Hong Kong's average daily domestic fresh water consumption per capita is about 150 litres. Around 40% of that is used for bathing, 10% for laundry and the remaining 50% for cooking and other purposes.

It is just a visible part of our water consumption, merely constituting a small fraction of the total amount of water each of us actually uses everyday. There is greatly more fresh water invisibly embedded in commodities and particularly in food that we consume in daily life.

What is Virtual Water?

Virtual Water refers to the amount of water embedded in the production and transportation of products.

Virtual Water of our Food

For example, to produce one kilogram of wheat, we need about 1,000 litres of water, i.e. the amount of this kilogram of wheat is 1,000 litres.

Below is a brief illustration on the amount of fresh water consumed for the production of 1 kilogram of beef:

The amount of fresh water consumed for the production of 1 kilogram of beef
  Resources embedded in the production of 1 kilogram of beef Water embedded in the production of 1 kilogram of beef
(1) Water for grains - about 6.5kg of grains (e.g. oats) Producing this volume of feed requires about 15,300 litres of water on average
(2) Water for roughages - about 36kg of roughages (e.g. pasture, dry hay)
(3) Water for drinking Drinking and servicing require about 155 litres of water on average
(4) Water for servicing
Total: The virtual-water cost for producing 1 kilogram of beef requires about 15,455 litres of water

 

Fresh Water used to produce one kilogram of food / one litre of drinks

Fresh Water used to produce one kilogram of food / one litre of drinks
Food Fresh Water Consumed
Chocolate 24,000 Litres / Kilogram
Coffee Bean 18,900 Litres / Kilogram
Beef 15,455 Litres / Kilogram
Chicken 3,900 Litres / Kilogram
Rice 3,400 Litres / Kilogram
Bread from wheat 1,300 Litres / Kilogram
Coffee 1,120 Litres / Kilogram
Milk 1,000 Litres / Kilogram
Banana 860 Litres / Kilogram
Apple 700 Litres / Kilogram
Lettuce 130 Litres / Kilogram

If you wish to learn more about your dietary virtual water, please visit http://www.jcwise.hk/calculator/?lang=e.

 

Virtual Water of Products

Below is a brief illustration on the amount of fresh water consumed to make the products:

The amount of fresh water consumed to make the products
Products Fresh Water Consumed
A car 151,416 Litres
A cotton shirt 2,900 Litres
A pair of leather shoes 8,000 Litres
A pair of jeans 10,000 Litres
A smartphone 12,760 Litres

 

How Can We Help?

As responsible citizens of the world living in the global village, we should do what we can to ensure sustainable use of water resources. We can reduce water consumption by making smart choices in purchase and transportation and wisely consuming food/products that require less water for production without wastage.

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