Australian House & Garden

A watery footprint

 There is a sign on a highway nearby that tells me of our daily water use – me and the giant community I live in. Yesterday it told me we had use 193.7 megalitres (or 193,000,000 litres).

What is that in real numbers? Or better yet, how many buckets? Such a big number made little sense to me. I wondered how much of that I was responsible for using. How do I stack up against the average? What is MY water footprint?

Confounded things these footprints. Like working out your carbon footprint, it is not just about the liquid stuff-o-life that comes out of your taps that makes up your footprint but what water has been used across the globe to bring you stuff and services.

I have measured our water use at home by reading the meter and dividing it up amongst the folk in the house. We use around 120L each per day. I think this is pretty good (and I haven’t taken the chooks into the calculation) but I am not actually sure.

Give me a target. I like a target. It gives me a goal to work towards and a figure to compare myself to. With water restrictions all over our wide brawn land I think that Queensland has done a great job of really assisting people to reduce their water use. At a time of their toughest water restrictions last year they set a target of 140L per person. This was no doubt hard at first but, as hundreds of thousands of Queenslanders would attest to, very achievable. Even though the restrictions have been lifted a little to 170 L per person per day the average daily use is still around 140L. Once achieved anything else seems like a waste.

The trickier bit to factor into our footprint is the water used to create the products we buy and services we use. This is called ‘virtual’ water.

It is quite a thing to get your head around.

Take a cup of espresso coffee. The amount of water in the cup is about 125ml of water from your tap but it took roughly 140L of water to grow, harvest, process and transport it to you.

And a kilo of beef. I know poor old cows get blamed for everything but it takes around 15,500L to produce 1kg of beef. This takes into account the grain they eat, the water they drink and all the processing and transportation required to get it onto your plate.

Below are a few products and their ‘virtual’ water:


Global average virtual water content of some selected products (from Hoekstra and Chapagain, 2007)


So next time you’re thinking about your water use look beyond the tap, the flushing toilet and the garden hose and tap into the water use of all the other bits you consume in your life.

I must admit I struggle to see how it takes 135L of water to grow one egg, especially since the chooks have a dust bath and eat all our scraps and only a cup of grain a day but maybe that is the benefit of having your own fowl play in your backyard.

• Posted By: Going Green at 3.33PM

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