... is the amount of water you consume indirectly ie: the amount used to grow the food and make the products that are imported.
The average UK citizen uses about 100 cu meters pa directly through the mains supply. This is dwarfed by your virtual consumption which is a staggering 1,000 cu meters per person pa. For a family of 4 that is about one and half olympic swimming pools.
The figures come from a new study by the University of Twente in the Netherlands and are illustrated graphically in this month's Scientific American.
Other big importers are Germany, Italy, Mexico and Japan. The biggest exporters are the USA, India, Australia and Brazil. Nearly all the world's water consumption goes into food production. One of the big factors in the equation is the amount of meat produced and imported or exported.
Conclusion: We may worry about own rainfall but perhaps we should worry a little more about the droughts in other countries.