Every single thing which you are holding, sitting on or nibbling is water. In the same way as plants and produce need water to grow, the computer you are typing on required liters of water during its manufacturing. The same goes for the clothes that you are wearing or the soaps and detergents that you use at home. We might not think of the water that is used in these products because we don’t see it bottled or coming out of our taps, but we are still consuming it. Our use of water resources directly impacts fresh water systems which is all the lakes and ponds, rivers, streams, springs, bogs, and wetlands
How much are we consuming?
Well, a lot actually given that from all the water on earth, only 3% is fresh water of which only 1% is readily available for our consumption (FAO, 2013). The Water footprint network (WFN) has estimated the average global consumption to be 1,240 m3 per year per person, with variations across regions and countries (Hoekstra. Y, A et al., 2011). Countries like Peru, China and the Democratic Republic of Congo use on average 600 to 800 m3 of fresh water per year per person. While countries like the USA and Russia have a much higher average of 2,100 to 2,500 m3 per year per person.
In 2002 Arjen Y. Hoekstra (a water management professor at the University of Twente) presented the concept of The Water Footprint. This serves as a tool that tells us how much water is required to produce the goods and the services that we consume, be it food, clothing, or the running of a multinational company. It quantifies the impact of humans’ consumption patterns on freshwater system by looking at the full production process from the supply chain to the end user. This means that is looks at the water that is used directly and indirectly in the process. In so doing, making government, companies, and individuals are accountable for their water use (Hoekstra. Y, A et al., 2011).
What is wrong with a large water footprint?
Many people have the misconception that water’s status of renewability means that it is endless source. A renewable resource is not endless; rather it means that the natural rain cycle replenishes the resource. Water is continually moving throughout the planet, with each climate receiving its own kind and volume of precipitation so its availability in regions varies. If a community overuses or pollutes its water source, the source can temporarily run out. However through conservation efforts water resources can eventually be restored.
In the Netherlands the total water footprint is 23,000 million m3 per year meaning that every individual living in the Netherlands consumes 4,000 litres of water per day. However only 5% of this is internal, while the other 95% is external (Ibid). Water use in a globalised world means that products are not always consumed in their country of origin, water consumption is externalised to the countries producing the goods and services. This however does not mean that the consuming countries are not accountable for their consumption.
Rather, global water consumption is tracked at river basin and aquifer level, which is particularly useful to understand the implications of water consumption or pollution within that region. It especially matters in regions prone to water scarcity in countries like Chile, Malta or Kuwait, as further extraction or pollution of their water resources can be detrimental to their national water resources and global water systems.
The water food print is made up of three components; blue water, green water, and grey water.
So, by knowing how much and where, the water footprint informs us on how better manage our use of fresh water resources.
Why does this matter?
Let’s imagine that all the freshwater available to us for consumption was a 1 litre bottle. This one bottle of water needs to serve all freshwater ecosystems with their species, as well as our growing industries and communities. Global estimates suggest that of this single source of freshwater 70% goes to growing our food, mainly for irrigation in agriculture (FAO, 2014).
Water use in food production varies from crop irrigation to food processing i.e. cleaning, sanitizing, peeling, cooling. It is essential therefore for our food supply chain to have a healthy constant source of fresh water to grow produce and feed animals. Yet, one-third of food produced for human consumption is thrown out (FAO, 2014).
Some of the most commonly wasted food are bread, milk, and apples.
Using the Water Footprint product gallery, we can now look at the estimated water costs of these products.
The global average water footprint of wheat is 1827 litres per kg
The global average water footprint of milk is 1020 litres per kg.
On average, one apple costs 125 litres of water.
The global average water footprint of beef is 15400 litres per kg.
The Water footprint shows us that it is not just the valuable food being wasted but also such finite resources as water. FAO (2013) estimates that globally, the blue water footprint i.e. the consumption of surface and groundwater resources of food wastage is about 250 km3. While conservative estimates of water loss caused by discarded food indicate that about half of the water withdrawn for irrigation is lost. Once food is dumped, it sits landfills which leads to harmful soluble substances (via leachates and runoff) to seep into the ground. This pollutes waterways and groundwater which negatively impact both land and aquatic biodiversity (Hoekstra. Y, A et al., 2011).
What can we do to shrink our Water footprint?
There are many positive contributions we can make.
We can start off by calculating our personal water footprint. This will give us a clearer idea of how much water our lifestyle requires and how sustainable this is. Once we know this we can start making more conscious decisions about our dietary choices and consumption habits.
Of course, this does not fall on us individuals. It is also important to voice our concern and let governmental representatives know that we care about water and want it to be used and managed in a sustainable way across the globe. We can do this by electing representatives with a sound water policy and being an active global water citizen.
In that way governments can set up coherent policies which look at multiple industries, and work to ensure sustainable production of produce and services from importing countries. Similarly, industries need to implement resource efficiency in their production process and ensure transparency in their water use.
Happily, this shows how by learning to reuse food, reducing our food waste, and recycling food scraps we’d also be making a contribution to shrinking our water footpring. By fighting food waste we’re also alleviating pressure from water sources and assuring the sustainability of fresh water systems. In our mission to fight food waste we’d;
- Reduce blue water consumption for irrigation in agriculture
- Require less blue water for food processing
- Downsize the amount of food waste in landfills and the resulting leachates and run off
- Reduce the possibility of contamination of waterways and groundwater
Looks like a win- win!
FAO. (2013). Food wastage footprint Impact on natural resources Summary report. FAO.
FAO. (2014). Food wastage footprint Full-cost accounting Final Report. FAO.
Fao. (2014). Mitigation of societal costs and benefits of food waste. Fao.
FAO. (2014). The Water-Energy-Food Nexus; A new approach in support of food security and sustainable agriculture. Rome: FAO.
Hoekstra, A. Y., Chapagain, A. K., Aldaya, M. M., & Mekonnen, M. M. (2011). The Water Footprint Assessment Manual; Setting the global standard. London: EarthScan.