Saving water with the iPhone

How much water does it take to grow a kilo of apples or fresh lettuce? And how about a kilo of pasta, a jar of pasta sauce or a packet of sweets? Perhaps one day, all products will bear a label indicating their water footprint, in other words, the amount of water that goes into their manufacture.

This is the goal of a study by Australian water conservation specialist Brad Ridoutt, who explains: "Most people have no idea how much fresh water they're consuming. For example, food and energy production account for nearly 90% of the world’s water consumption''. In fact, you may be astonished to learn that a kilo of beef takes 16,000 litres of water to produce, or that a cup of coffee requires 140 litres.

The idea of measuring the water footprint of various products on the supermarket shelf has aroused the interest of ISO (International Organisation for Standardisation), the organisation which compiles the world’s measurement standards.

In the meantime, there is already a water footprint application for the iPhone, which can be downloaded from the website You can choose from different categories (food, beverages, products and household), calculate how much water you’re using and even compare different products, to select the one with the lowest water footprint.