Virtual water, the cumulative of hidden water

Ali Mohtashami

(Postdoc Researcher of UNESCO Chair on Aflaj Studies and Archaeohydrology, University of Nizwa)

Virtual water is the “hidden water” in the goods, products, services and processes people buy, sell and use every day. On the other hand, virtual water is a concept that reveals the cumulative hidden impact of water consumption in our daily lives. When we buy or use products, we also indirectly consume virtual water used throughout their supply chain. This hidden water extends beyond and is considered separately from the visible water we use for domestic purposes, drinking, cooking, and cleaning.

The virtual water concept was first introduced by Dr. Tony Allan in 1993, a Middle Eastern specialist [1] [2]. Dr. Tony Allan reached this idea after researching Middle Eastern and North African countries that were able to meet their food needs despite water scarcity. He mentioned that these countries, in order to overcome water scarcity in their environment and economies, imported food from water-rich countries.

Having a pervasive knowledge of “virtual water” able the humans to gain a better understanding of its implications on water consumption. It allows us to know the indirect impact of our choices on water resources and the interdependence and water connections among regions. In addition to reducing their own water stress, virtual water allows regions with limited access to water to import goods that require a lot of water, increasing their dependence on external sources of water. Therefore, the exhibition of virtual water makes our actions become more aware of the hidden water impacts on the environment. This awareness is critical for pursuing and adopting sustainable goals and responsible consumption.

 Choosing products that use fewer resources and supporting companies that prioritize water efficiency, can significantly minimize our virtual water footprint and reduce our impacts on the environment. Moreover, virtual water emphasizes the necessity of developing strategies to manage water locally and globally. The following table shows some of the products and their hidden water content. The mentioned products include foods and goods.

According to table 1, for just drinking a cup of coffee, 140 liters are consumed indirectly. If a man averagely drinks 3 cups of coffee per day, in a year, more than 153000 liters are consumed. 

The following figure (Figure 1) is derived from a study conducted by Islam et al. (2007). They drew this figure assuming that imports were equally distributed across different grids based on population density. 

Export of virtual water	Import of virtual water
Figure 1. Virtual water trading among the countries [4]

In another table, one can find the average virtual water content of some selected products between 1997 and 2001 (m3/ton) based on information from some countries. 

By raising awareness of hidden water footprints, encouraging responsible water usage, supporting initiatives that develop water conservation, promoting water-efficient technologies and by implementing responsible irrigation practices, we can take action within our community and it will be possible to conserve water resources by reducing the consumption of that resource. For instance, if food or products are exported to a dry region, there is no requirement for water consumption in the dry region to produce those goods. 

It is therefore beneficial for individuals to be familiar with this concept. Following listed are some of them:

• Water Awareness

• Water Conservation

• Sustainability

• Water Management

• Global Water Security

• Equity and Social Justice

• Climate Change Adaptation