Many people already consider the environmental impact of the foods they choose or the amount of energy they consume. But while the concept of a carbon footprint has become fairly widespread in recent years, the majority of consumers remain unaware of the water footprint associated with the goods they buy.

Water footprint is a calculation of the freshwater needed to produce goods and services. For example, a cup of coffee (7g) requires 130 litres of water to produce, while a pint of beer has a footprint of 168 litres. These figures take into account the entire chain of supply required to bring goods to market—from growing crops to processing. The non-profit Water Footprint Network (WFN) establishes standards for measuring water use and carries out studies of specific products and sectors to come up with reliable water footprints.

Water is often a hidden cost of the goods we consume, since prices do not reflect water consumption and no labelling system is currently in place to disclose this aspect of production. Many higher-order goods such as animal products use water at an unsustainable rate. According to a 2010 study, 1kg of beef requires a whopping 15,400 litres of water to produce compared to 1,644 for cereals and 4,500 for pulses. (Mekonnen and Hoekstra).

According to the WFN, water scarcity affects 2.7 billion people per year, and water resources are intricately linked to the global economy. The hope is that an awareness of water footprint would help consumers to make different, more sustainable choices. The WFN also calculates corporate and national footprints to highlight the economic consequences of water use and to help reshape water policies.

You can calculate your personal water footprint and see water statistics for the products you consume on their website.