Water is the primary necessity of life for people, animals and crops. About 70% of the earth’s surface consists of water. Only 2.5% of it is fresh water and 0.25% of it is usable for humans. The vast majority is trapped in ice sheets and glaciers. In the Netherlands, approximately 2.3 million liters of water are used per year. About 2% of this is household use. The remaining 98% is indirect water consumption. This indirect water consumption is mainly in the production of food, clothing and industrial products. But what is the indirect water consumption of certain products and how is that calculated?
Chapters
- Virtual water
- Large consumers of water
- The water footprint of a country
- 1 liter of beer = 155 or 45 liters of water?
Virtual water
The indirect water use that is necessary for the production of food, clothing and industrial products is virtual water mentioned. For example, for one cup of coffee, 140 liters of water are needed. For this calculation, the amount of water used is calculated for each step in the production process. The amount of water required for the growth of the plant on which the coffee bean grows, the coffee harvest, the first operation of the bean, the transport, the next operation, the packaging, storage, sale to brewing the cup of coffee. (1 Of course, this cannot be calculated to the liter because a lot depends on the climatic conditions, not every plant that grows coffee beans needs the same amount of water to grow. Also, not all operations of the coffee bean are the same in every production process from different suppliers. All figures mentioned are therefore an approximation. Also, not all water is consumed but used and a large part returns to the water cycle.
Large consumers of water
The Netherlands imports many products and uses a lot of water abroad in this way. Only 11% of our water footprint (total water consumption, direct + indirect) is in the Netherlands and the rest of our consumption abroad. Which sectors are the major consumers of water? The first place is occupied by the agricultural sector. Agriculture has many ‘thirsty crops’ such as cotton, sugar, coffee and grain. A lot of water is also needed in the production of flowers, for which we are known ourselves.
Product | Water usage |
---|---|
1 kilo of rice | 3,400 liters of water |
cotton T-shirt | 2,700 liters of water |
1 kilo of sugar | 1,500 liters of water |
1 kilo of soybeans | 1,800 liters of water |
1 kilo of wheat | 1,300 liters of water |
1 kilo of corn | 900 liters of water |
1 kilo of bananas | 860 liters of water |
1 bag of chips 200 grams | 185 liters of water |
1 cup of coffee | 140 liters of water |
1 glass of wine | 120 liters of water |
1 glass of beer | 75 liters of water |
1 apple | 70 liters of water |
1 orange | 50 liters of water |
1 slice of bread | 40 liters of water |
1 cup of tea | 30 liters of water |
The livestock sector is in second place for large consumers. 98% of the water use in the Netherlands is indirect water use, 67% of this is for the production of agricultural goods. Of this 67%, 30.8% is for meat and other animal products. Animals need a lot of food, which is sometimes also grown especially for them.
Product | Water usage |
---|---|
1 kilo of beef | 15,500 liters of water |
1 kilo of cheese | 5,000 liters of water |
1 kilo of pig | 4,800 liters of water |
1 kilo of goat | 4,000 liters of water |
1 kilo of chicken | 3,900 liters of water |
1 hamburger sandwich | 2,400 liters of water |
1 liter of milk | 1,000 liters of water |
1 egg | 200 liters of water |
The water footprint of a country
How is a country’s water footprint calculated? The water footprint is the total volume of water in cubic meters per year required to produce the goods consumed in a country (1). This is calculated on the basis of three criteria:
- domestic water consumption for producing goods and services consumed in the country;
- water consumption in other countries for the production of goods to be consumed in the country and for export;
- direct water consumption for household consumption: drinking, washing, cooking.
There are several factors that influence a country’s water footprint. First, what and how much is consumed. Second: the influence of the climate, in a warmer climate there is more evaporation of water and more water is therefore needed to grow crops. Thirdly, how is the water handled, for example during irrigation. In production companies, too, it is often possible to use water more efficiently by recycling.
1 liter of beer = 155 or 45 liters of water?
A good example of climatic conditions and the production process is the brewing of beer. In collaboration with WWF, beer brewer SAS Miller has had two water footprints made. SAS Miller has a brewery in South Africa and one in the Czech Republic. The water footprint of the South African brewery came to 155 liters for the production of 1 liter of beer. The Czech brewery has a water footprint of only 45 liters for the production of the same liter of beer. This big difference is mainly in the grain cultivation that is required for the brewing process. In South Africa, 98% of the water footprint went to grain cultivation. Due to the warmer climate, grain cultivation requires more water. In the Czech Republic, 90% of the 45 liters was needed for cereal cultivation.