Water footprint: the hidden water

On 22 March 2021, World Water Day was celebrated to raise awareness of the global water crisis. Water is the lifeblood of ecosystems, on which our present and future food and nutritional security depends. Yet, freshwater resources are dwindling at an alarming rate.

70% of the earth’s surface is covered with water. It sounds like a lot, but only 0.027% of the fresh water on the planet is available for use. In fact, only 3% of it is fresh and most of it is ice.

What is a water footprint?

Everything we use, buy and eat takes water to make. The water footprint measures the amount of water needed for each of the goods and services we use. It can be measured for a single process, such as growing rice, for a product, such as a pair of jeans, or for an entire multi-national company.

The water footprint has three components that together provide a comprehensive picture of water use:
Green water footprint is water from precipitation that is stored in the root zone of the soil.
Blue water footprint is water sourced from surface or groundwater resources.
Grey water footprint is water required to assimilate pollutants to meet specific quality standards.

The hidden water behind our diet

The ‘water we eat’ every day through food is much more than what we drink. Depending on the diet, it ranges from 2,000 to 5,000 litres for a person’s daily consumption.

Farming accounts for almost 70% of all water withdrawals. About 27% of the water footprint of humanity is related to the production of animal products.  By far the largest contribution (98%) to the total water footprint of all animal products comes from the cultivation of feed.  This step is the most far removed from the consumer, which explains why consumers generally have little notion about the fact that animal products require a lot of land and water.

Water stress

The level of water stress is defined as the ratio between total freshwater withdrawals by all economic activities and total available freshwater resources, after taking into account environmental flow requirements essential to maintaining ecosystem health and resilience.

Water problems are often closely tied to the structure of the global economy. Many countries have significantly externalized their water footprint, importing water-intensive goods from elsewhere. This puts pressure on the water resources in the exporting regions.