Water Use in Consumer Goods | UCF-1.2.1

Water Use in Consumer Goods is a topic with rich potential for a teaching unit that integrates geography, environmental education, mathematics, and critical thinking—even at the primary school level. Here’s a step-by-step breakdown of how much water is used for consumer goods, how you could translate that into a teaching unit, and how to meaningfully include geodata like river flow.

Understanding Water Use in Consumer Goods

Water is used not only in drinking and sanitation but also in producing almost everything we use—called virtual water. Some examples:

Item	Approx. Water Used to Produce
1 sheet of paper	10 litres
1 cotton T-shirt	2,700 litres
1 hamburger	2,400 litres
1 apple	125 litres
1 pair of jeans	7,000–10,000 litres

The key concepts of virtual water are foundational for understanding how much water is hidden in the production of goods and services we consume.

 

Virtual Water Concepts

1. Virtual Water

• Definition: The total volume of water used to produce a product, from start to finish.
• Example: A cup of coffee requires around 140 litres of water—mostly to grow the coffee beans.
• Why it matters: It shows how we use water indirectly, not just from the tap.

 

2. Water Footprint

• Definition: The sum of all the water a person, product, or country consumes, including virtual water.
• Types:
  • Blue water: Irrigation or groundwater used
  • Green water: Rainwater used for crops
  • Grey water: Water needed to dilute pollutants
• Classroom idea: Have pupils trace the water behind a simple meal or outfit.

 

3. Product Water Use

• Water is used at multiple stages:
  • Agriculture (e.g., growing cotton)
  • Manufacturing (e.g., dyeing jeans)
  • Transportation (fuel, packaging)
• Example comparisons for children:
  • Apple = 125 litres
  • T-shirt = 2,700 litres
  • Hamburger = 2,400 litres

 

4. Global Trade of Virtual Water

• Products made in water-rich countries may be consumed in dry regions.
• Concept: When you import a product, you also “import” the water used to make it.
• Example: Europe imports coffee, chocolate, cotton, etc., which are water-intensive.

 

5. Water-Intensive vs. Water-Saving Choices

• Teaching point: Not all items use the same amount of water—some choices use much more.
• Simple comparisons:
  • Lentils vs. Beef: Lentils use much less virtual water per gram of protein than beef
  • Showers vs. T-shirt: A week of showers uses less water than one cotton shirt

 

Teaching Unit Idea: “How Much Water Hides in Our Things?”

Grade Level: Primary ans Secondary School

Subjects Covered: Geography, Math, Science

Timeframe: 3–5 lessons (can be expanded)

Learning Objectives

• Understand the concept of virtual water
• Compare virtual water consumption of different products
• Use real geodata to understand water flow in nature
• Develop a critical attitude towards consumption
• Practice measuring, comparing, and data interpretation

 

Suggested Lesson Flow

Lesson 1: What is Water Used For?

• Brainstorm: “Where do we use water?”
• Introduce virtual water with simple examples
• Picture cards showing objects and their water consumption (e.g. burger, T-shirt, apple)

Lesson 2: How Much Water Is That?

• Use containers or visual analogies:
  • 1 litre bottle = 1 litre of water
  • Create a chart: e.g., line up bottles to show 2,700 litres = cotton shirt
• Pupils sort everyday items by water consumption

Lesson 3: Compare With Nature (Geodata Integration)

• Introduce river data: e.g., “How much water flows through the Danube/Elbe/etc. per minute?”
  • Example: The Danube in Vienna flows at around 1,900 cubic meters per second = 1.9 million litres per second
• Ask: “How many T-shirts is that every second?”
• Use simple math:
  • 1.9 million litres / 2,700 = ~700 T-shirts worth of water flowing every second
• Use online maps or a pre-selected interactive water flow map (e.g., from national hydrology services)

Lesson 4: What Can We Do?

• Introduce the concept of water footprints
• Reflect: “What can I do differently?” (e.g., eat less meat, use clothes longer)
• Mini project: Pupils create posters about virtual water or their personal water hero (from memory | closed book approach)

 

Tools for Including Geodata

WWF Risk Filter Suite: https://riskfilter.org/water/explore/map

Why This Works Well in Primary School

• It’s tangible (water = bottles)
• It’s visual and spatial (maps, rivers, containers)
• It connects personal behavior to global issues
• It promotes systems thinking in a very basic form

Extensions

• Compare water use in different countries (per capita)
• Link with climate change or drought events

 

Sample Worksheet: “How Much Water Hides in Our Stuff?”

“Virtual Water Comparison”

Example: True or False?

1. It takes more water to produce a hamburger than a cotton T-shirt.
2. A pair of jeans uses more water than 50 apples.

 

Interactive Activity: “Water Bottles on the Wall”

Materials:

• Empty plastic bottles or printed bottle cutouts
• Labels with different litre values (1L, 100L, 1,000L)
• A poster or wall space

Instructions:

• Each child gets an item (T-shirt, burger, apple).
• They collect the matching number of bottles (scaled, e.g., 1 bottle = 100L).
• They “stick” or stack bottles to show how much water their product “uses.”
• Compare and reflect: “Which product uses the most water? Why?”

Learning Goal: Visualize invisible quantities, practice estimation and comparison.

 

Digital Map Task: “River vs. Burger”

Objective:

Compare water in a river to the water used in making products.

Tool:

• Google Earth or printed river maps
• Simple data table (prepared by teacher) showing:
  • River name
  • Location on map
  • Flow rate (litres/second)
  • How many hamburgers or T-shirts this would equal

Example Table Entry:

River	Location	Flow per Second	How Many T-Shirts per Second?
Elbe (Germany)	Magdeburg	500,000 L/sec	≈ 185 T-shirts
Danube (Vienna)	Austria	1,900,000 L/sec	≈ 700 T-shirts
Thames (London)	UK	65,000 L/sec	≈ 24 T-shirts

 

How to Teach These to Children

• Use visual comparisons (e.g., water bottles or bathtubs)
• Create sorting games with product cards by water usage
• Involve maps or rivers to show water availability vs. use
• Encourage questions and critical thinking: “What can I change?”

 

Everyday Object Equivalents

Relate virtual water amounts to familiar water quantities:

Product	Virtual Water Used	Visual Equivalent
One shower	~50 L (5 mins)	One shower head pouring out water
One bath	~150 L	A full bathtub
Jeans	~10,000 L	~66 bathtubs
T-shirt	~2,700 L	~18 bathtubs

 

Location-Based Comparison Map

Show a river on a map (e.g., Elbe or Danube), and label how many litres flow per minute. Then compare:

• “The river brings 2 million litres every minute.”
• “That’s enough to make 740 T-shirts every minute!”