1. The water footprint of a person, family, community, nation is the total volume of fresh water used to produce the goods (including food) and services consumed, in other words, the water footprint is the volume of water needed to sustain a personal or family lifestyle or, indeed, a global population;
2. The virtual water content of a food is the volume of water that has been needed to grow, process and prepare the food instead of the actual nutritional content and it is the virtual water content that we consider when we talk about the water footprint of a food. food. For example, an apple has a virtual water content of 70 Liters of water, an orange of 100g 50L; 100g of chicken meat 390L and 100g of beef 1600L;
3. The water footprint of a food or product can increase significantly if the production process generates wastewater that must be treated or waste products that must be diluted before being disposed of;
4. The water is called blue when it is surface water or is extracted from groundwater and it is called green when it is infiltrated rainwater;
5. A food can have a different footprint depending on where it is produced. For example, if the cotton product is produced in China, it has a virtual water content of 5,404 m3/ton, but if it is produced in India, it will have a virtual water content of 21,563 m3/ton. The variation will depend on the amount of rainfall, the available water in the soil and the amount of water needed for irrigation and the water needed to dilute the processing by-products before disposal.
6. Virtual water consumption varies between countries depending on the level of personal consumption in terms of food, goods and services. In the UK it is 1245 m3/person/year, in the US 2483 m3/person/year, which is three times the level in China.
7. The per capita consumption of virtual water contained in our diets varies according to the type of diet, from 1 m3/day for a survival diet, up to 2.6 m3/day for a vegetarian diet and more than 5 m3 for a diet based on American-style meat. diet.
8. The water footprint of a food is often not found in the country where the food is consumed;
9. A nation’s water footprint can be described by location as internal, when the nation’s footprint is within its national borders, or external when goods are imported and the water used to produce those goods is external to the country;
10. The UK has a relatively high water import dependency of 70%. This is compared to other European countries such as Switzerland (79%), Belgium-Lux (80%), the Netherlands (72%), but much more than France (37%).