Did you know that a single orange contains eighty litres of water?
We’re not talking about the amount of water you literally consume when you enjoy this delicious fruit. We’re talking about embedded water. You can’t see it, but it’s there.
Simply put: embedded water (also known as hidden and virtual water) is an estimate of the total amount of water needed to produce a product – taking into consideration everything from growing crops, to keeping livestock, to transporting goods, to washing factories.
This means that our actual daily water consumption is far greater that we might ever realise. On average, water consumption worldwide is said to amount to approximately 90 litres per person per day - with the average Briton using 150 litres daily for drinking, cooking, cleaning, washing and flushing.
In reality, when we include embedded water, the average Briton actually consumes over 3400 litres every day!
In the UK, approximately 65% of the water we consume is embedded in the food we eat. For instance, we need 1000 litres of water to produce just 1 kilogram of wheat. And you can multiply that figure by 15 times for beef. This is because water is needed to feed and maintain the cows throughout their lifetimes. So every time we chuck a burger on the BBQ, we’re about to eat 2400 litres of embedded water – excessively more than an orange!
Blue and Green water – what’s the difference?
Some plants are particularly water intensive; for instance it takes 140 litres to grow enough coffee for one cup. But it should be noted, before you kick the morning latte habit, that there are two types of water – green and blue.
Green water is precipitation which becomes trapped in soil, and has less of an impact on the environment than fresh surface and ground water known as blue water.
Cotton, for instance, uses blue water intensively for irrigation. It takes 11,000 litres to produce a single pair of jeans, the majority of which is blue water.
Back to oranges!
It’s difficult to say exactly how much water is in each product we use. Even in the same product there can be variation depending on where it’s grown or manufactured. Getting back to those oranges - a kilogram of oranges from the USA contains about 175 litres of embedded water but a kilo from Australia contains over three times more. This is due to differences in climate, irrigation and production techniques and technology, among other factors.
A water footprint is not a direct measure of environmental or social impact. Water has a much greater social and environmental cost in an area of water scarcity than in an area of water abundance, and be more much harmful during a dry season than during a wet season.
We import huge amounts of ‘embedded water’ to the UK. In fact about 70 percent of the UK’s water footprint is external. And our consumption here in the UK may be adversely impacting lakes, rivers, and aquifers in other countries.
The realisation that we are consuming more water than we might have originally thought due to these surprising statistics should make us more aware of our need to reduce water consumption.
Over to you
Find out your water footprint with an online calculator. We're developing one for this site too.
Meat is a notable culprit for boosting our water footprints. While a beef burger contains 2400 litres of virtual water, a 150g soy burger contains around 160 litres. If you can’t envisage yourself becoming a full-time vegetarian, then consider meat-free Mondays. It will not only significantly reduce water (and carbon) footprints, but could also have great health benefits. It’s a win all round. (Or, if you feel firmly dedicated to the cause, maybe you could try an insect diet like these HSBC employees in North America!)
Call on retailers and food manufacturers to deliver water sustainability through their stores and supply chains, and support UK government to implement policies relating to the sustainable use of water
As ever, signing up to FreshWater Watch is one of the best ways that you can help us to understand how to preserve our fresh water.
Next time: F is for Ferruginous Pochard
A is for Alien Invasions; B is for the Biggest!; C is for Crickets in your lunchbox; D is for Data. Or is it datum?; E is for Eighty Litres of Water in an Orange; F is for Ferruginous Pochard; G is for Going, Going, Gone?; H is for Heroes; I is for Industrial Revolution; J is for Jigsaw Puzzles; K is for (Everything including the) Kitchen Sink; L is for Life itself; M is for Microbeads; N is for Namedropping
What's your water footprint?