We hear a lot these days about water, either there's too little or too much, rarely what we think we need. Now a relatively new concept surrounding water is emerging... that of a water footprint. Humans use water in a large variety of ways from the obvious such as drinking, washing and irrigating; to the not so obvious such as steel production, chemical plants, clothing and textiles, indeed almost all industrial production.

A water footprint is a measure or an indicator of total water use taking into account both direct and indirect water use. The water footprint of an entity or indeed an individual, is defined as the total volume of freshwater that is used directly as well as that used to produce the goods and services consumed by the entity.

According to the Water Footprint Network, (WFN) a Dutch based organisation out of the University of Twente, the average water footprint of Australia is between 1300 and 1500 cubic metres per capita, (1.3 to 1.5million litres per person) which is twice that of China, but only 60% of countries like the USA. So in Australia, the average family household of four has a water footprint around 5 million litres a year.

It sounds hard to believe, but consider these statistics also quoted by WFN:

• A cup of coffee has an average global water footprint of 140 litres;
• one kilogram of beef requires some 16,000 litres of water;
• a litre of milk, needs 1,000 litres of water;
• a kilogram of wheat takes 1,350 litres of water;
• and so on.

Average national water footprint per capita (m3 /capita/yr). Green means that the nation’s water footprint is equal to or smaller than global average. Countries with red have a water footprint beyond the global average. Graph courtesy of Water Footprint Network.

When looked at in that context it seems easy to see how the average person in Australia is responsible for 25,000 to 30,000 litres a week. Indeed there are some in my office who are responsible for nearly 1000 litres a day just through coffee consumption alone!

To check out your own footprint visit the Your Water Footprint section on the WFN site.

It's a fairly arbitrary calculator, and very generalised, but it does shock you see just how big our impact is. For instance by selecting a category of average meat consumer and comparing it with a vegetarian – all else being equal – it comes up with a difference of almost 30 per cent.

So what do we do with this information?

The main thrust of the movement is for people to build awareness of their own usage; because it's only through this awareness that people will seek to change both their personal habits and also to bring about change on a national and international level. It has often been said over the past decade, that the next big rivalries amongst nations will be about water, and that will be far more dangerous than our recent disputes about oil, after all oil does have substitutes, water does not.

Also check out www.savewater.com.au

Written by Gavan Farley

Image credit: Chris Young via Flickr Creative Commons.