Unit 8: Our Water Footprints
Embodied water game activity guide and handout
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This project was funded by the Department of Sustainability and Environment.
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Unit 8: Our Water Footprints
Embodied water game activity guide
Estimated duration: 20 minutes Aim •
To develop an understanding of the water required to produce foods and materials.
Outcome By the end of this class, students will be able to: • estimate the quantities of water used in the production of several common foods and materials.
Resources • •
Handout: Embodied water game (included below). One set per group of 2‐4 students. One pair of scissors per group.
Activity Description 1. 2.
3.
4.
5. 6.
Provide each group of 2‐4 students with a set of picture cards and have them cut them out. Explain to students the concept of embodied water being the water involved in growing, processing and distributing the product (see additional information below). Ask students to move the cards into an order of largest to smallest embodied water content. Encourage them to discuss the each item with members of the group. Have students place a figure from between 10 and 20,000L next to each picture. They will probably find it difficult but you can point out that, as they are calculating the “hidden” water content in these foods and materials, it is supposed to be difficult. Encourage them to have a go anyway and not get too worried about being right or wrong. Ask each group finalise their lists, and then go through the solutions. Discuss any anomalies and the use of water in growing, processing and transport phases of the food production cycle.
Additional teacher information: What is embodied water? 'Embodied water' is the amount of water used during the growing, processing and transportation of the goods we use or consume, or the services we use. Some of the items we take for granted in our lives – food, clothing, furniture and many building materials have very high embodied water content. An example of the embodied water concept is: Page 2 of 5
To eat a bowl of pasta 1. The grain has to be grown (through rain or irrigation) 2. The grain is processed into pasta which requires water as an ingredient and to clean the machines after making it 3. The pasta is then packaged (water is used in the packaging manufacture and the printing process of the brand name) 4. The pasta and packaging is then transported to the supermarket with the transport using water from coolant in the motor to washing the vehicle 5. Finally, once you buy the pasta you have to cook it up in a pot of water All of these steps use water. Embodied water is particularly high for beef because cows drink a lot of water throughout their lifetimes and also eat a lot of fodder and grain which needs water to grow. Embodied water in wheat is much lower partly because wheat has a much shorter lifespan before being harvested. Beef has a much higher embodied water content than poultry. Embodied water is also known as virtual water, embedded water and hidden water. There is no standardised way of calculating embodied water, so some figures only include irrigation water, whereas others include rainwater. Environmentally, water use from irrigation is a much bigger problem than rainwater use, because we divert huge amounts of water from our rivers into irrigation and don’t leave enough to support healthy river ecosystems. Note that the lack of a standardised calculations means that embodied water figures for the same thing from different sources will vary. Answers It is estimated that the following amounts of water are required to produce the various products: • 15,500 litres of water for 1 kg of beef • 3,400 litres for 1 kg of rice • 2,700 litres for 1 cotton shirt • 2,400 litres of water for 1 hamburger • 1,500 litres of water for 1 kg of cane sugar • 1,300 litres of water for 1 kg of wheat • 1,000 litres of water for 1 litre of milk • 140 litres for 1 cup of coffee • 75 litres of water for one glass of beer • 40 litres of water for one slice of wheat bread • 10 litres of water for one A4‐sheet of paper Source: www.waterwise.org.uk
Student Roles and Responsibilities Participate in agreed tasks Contribute to class discussions Complete activities and worksheets
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Work cooperatively with others
Level of Teacher Support Facilitate discussion Organise materials and equipment Provide encouragement Introduce tasks and activities Provide assistance when requested
Assessment To use this learning activity as an assessment task, collect evidence such as: Teacher checklist and observation Teacher checklist for class discussions
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Unit 8: Our Water Footprints
Embodied water game handout
1 kg of wheat
1 kg of rice
1 A4‐sheet of paper
1 kg of beef
1 glass of beer
1 cotton shirt
1 cup of coffee
1 slice of wheat bread
1 hamburger
1 litre of milk
1 kg of cane sugar
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