# Australian Bureau of Statistics

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 MAT 02 – Water - Use It Wisely

You can download the activity, solution and rubric in Word (doc) format at the bottom of the page.

Subject Area
Mathematics

Suggested Level
Years 7–9

Overview
This activity focuses on how Australians use water. State/territory comparisons are made between water use and where the water is used in the household. Students will need to make some simple calculations to make these comparisons. An extension exercise is also provided where students solve a set of equations to estimate the potential for water wastage.

Requirements
• Calculator
• Computer
• Internet connection

Instructions
It is vital that we use water wisely and respect it as a precious resource. Water is an essential part of our lives. It is important to be aware of how we use water and what we can do to assist with water conservation. Our environment is under great stress facing issues such as decreasing river flows, soil salinity and deforestation.

PART1: Water use by location

Task 1: Graphing household water use by state and territory
The table below contains the percentage of household water used in different rooms and places within households in 2000-2001. Data is rounded to whole numbers.

 TABLE 1: PERCENTAGE OF HOUSEHOLD WATER USAGE 2000–2001 Location NSW Vic. Qld SA WA ACT AUS Bathroom 26 26 19 15 17 16 20 Toilet 23 19 12 13 11 14 15 Laundry 16 15 10 13 14 10 13 Kitchen 10 5 9 10 8 5 8 Outdoors 25 35 50 50 50 55 44

Note: Data not available for Tasmania and the Northern Territory.
Source: Australian Bureau of Statistics, Water Account, Australia, May 2004 (cat. no. 4610.0)

Read the table and complete the following questions:

1. Using the data in Table 1, draw a bar graph of household water usage for each state and territory.
2. Compare your state’s graph to the graphs for the other states and territories. Describe any differences and similarities.
3. Suggest reasons for the differences between states and territories.

Task 2: The effect of water efficient products on water use

The column graphs below show percentage water use by state and territory from Table 1.

 a) bathroom Figure 1: Percentage of Bathroom Water Use b) toilet Figure 2: Percentage of Toilet Water Use

The following graph uses data from Australian Bureau of Statistics, Environmental Issues: Water Use and Conservation Table 9 (cat. no. 4602.0.55.003).

Figure 3: Percentage of Water Saving Products by State and Territory

1. Considering the percentage of households with water saving products such as a water efficient shower head and dual flush toilet, comment on water use in the bathroom and toilet for the various states and territories.

PART 2: Calculating the actual volume of water use

The table below shows the volume of water used per household (kilolitre/household) for the year 2004–2005, 2000–2001 and 1996–1997.

 VOLUME OF WATER CONSUMED PER HOUSEHOLD (kL/household) NSW Vic. Qld SA WA Tas. NT ACT 2004 - 2005 219 209 323 244 468 372 399 248 2000 – 2001 252 251 372 286 497 326 420 298 1996 – 1997 253 263 347 236 341 181 585 280
Table 2: Volume of water consumed per household (kL/household)
Source: Australian Bureau of Statistics, Water Account, Australia, May 2004, Table 7.8 (cat. no. 4610.0) and Australian Bureau of Statistics, Water Account, Australia, May 2000-1 Table 9.6 (cat. no. 4610.0)

1. Draw a side-by-side column graph showing the volume of water consumed by each household by state or territory. Include all three sets of data on one graph using a different colour for each.
2. Comment on the change in the volume of water use over time.
3. Using Tables 1 and 2, calculate how many kL of water (i.e. the volume) each household used outdoors in 2004 - 2005 for each state and territory. Example: In 2000–2001, each household in NT used a total of 620kL and 25% of this was for outdoor use. Therefore, outdoor use is 620 x 0.25 = 155kL.
 Location NSW Vic. Qld SA WA ACT % Outdoors kL 2004 -2005 total
4. Choose a graph type and graph the volumes calculated in the previous question. Label the graph and axes appropriately. Comment on the important features of the graph.
5. A kilolitre is the amount of water that would fill in one cubic metre (1m x 1m x 1m). 1m3
Using 2004-05 data for your state or territory from Table 2, show the total amount of water used as a cube with dimensions correct to 1 decimal place. For comparison draw a scale drawing of yourself next to the cube.
6. Based on all the information, create a list of suggestions that will help reduce water use.

Extension

With a partner, list possible ways that water is/could be wasted around the home. List solutions to what can be done to decrease their household water consumption.

How much water is wasted per person in a year if they leave the tap running while they brush their teeth?
Complete steps 1 - 4 (below) as homework.

Step 1: Time how long it takes to brush your teeth in seconds. Call this tb.
tb = ______seconds

Step 2: Time how long it takes to fill a 1 litre (L) container at your bathroom sink (please use this water wisely). Call this tf. (Hint: make sure you have the tap running at a normal flow)
tf = ______seconds

Step 3: Calculate the flow rate in L per second.
flow rate = 1/tf
= L per second

Step 4: Calculate the water wasted by multiplying the flow rate by the time it takes to brush your teeth.
Water wasted = tb x flow rate
= L per second

Questions

1. If a person brushes their teeth twice a day and leaves the tap running while doing so, calculate how much water will be wasted over a week, a month and a year? Do the same calculation for a family of four.
2. Why are the figures calculated an approximation?
3. How could this calculation be improved?

References

Student Activity

Teacher Solutions

Marking Rubric

To provide any feedback regarding this activity, please contact ABS Education Services on 1800 623 273 or email education@abs.gov.au.

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