31/08/2011 08:53 BST | Updated 29/10/2011 06:12 BST

What's Your Water Footprint?

Renewed focus on the relationship between business, the consumer and water consumption emerged again last week in Stockholm at the annual World Water Week.

Awareness of our individual carbon footprints has steadily grown as we have come to realise in recent years that our behaviours are impacting the environment in many more ways than we ever thought possible.

While minds remain focused on carbon footprints and online calculators advise the consumer how much carbon they are using, little attention has so far been given to water usage. This looks set to change and present businesses across the spectrum with the additional challenge of managing their own water behaviours and a potential consumer backlash to poor water stewardship.

The water footprint concept was first mooted in 2002 as an alternative indicator of water use. Where traditional indicators of water use relate only to production, the water footprint takes into account the amount of freshwater used in the goods and services consumed or used in production.

An internationally accepted water footprint methodology has been devised and covers three categories - green, blue and grey water. Green water represents the natural water cycle that affects, say, crop production (i.e. rain). Blue water relates to water drawn from rivers, lakes and acquifers for the use in producing or manufacturing a product. Grey water represents the amount of water needed to assimilate the remaining pollutants after cleaning process / by product wastewater.

Importantly, the Global Water Footprint Standard devised by the Water Footprint Network helps build knowledge and understanding about how much water we use, where it comes from and how we each can take steps to make our water footprint sustainable. To that extent it differs from carbon footprinting which calculates emissions.

The water footprint methodology, therefore, is not an exact science. Water footprints can differ enormously between agricultural regions depending on the amount of rainfall that a region receives. As a recent report on water footprints by WWF cautioned there is also significant complexity in calculating the impact of one water footprint versus another on the environment and on communities. Whilst good for consumer awareness, water footprints are not yet effective tools for helping consumers choose between different products. Over time, and as methodologies mature and become more standardised, this is likely to change.

That said, the current water footprint calculators provide an indicative, and humbling, assessment not only of commercial water consumption but also our individual water consumption and use, as well as collectively as a nation.

For example it can take an average of 140 litres of water to produce each cup of coffee we drink, while the average hamburger requires around 2,400 litres of water. Water consumption habits broadly breakdown into the visible and invisible.

In the UK, about 1% of the water footprint is at home. The average consumer will use 21 litres of water per day for drinking, washing, cooking etc. The other 99% of a consumer's footprint is 'invisible'. In other words it relates to the products bought in the supermarket, or used in the workplace and in transportation. That includes 3,021 litres per day for agricultural products which become foodstuffs, and a further 405 litres per day for industrial products. Perhaps the most revealing statistic is that 75% of Britons' water footprint lies abroad.

Painful figures when you consider one billion people in the world don't have access to safe drinking water and over two billion people don't have access to water for sanitation.

A new concept, the so-called water, energy and food nexus, has emerged in the lexicon of policymakers in recent years. It highlights the interconnectivity of water, food production and energy requirements of the earth's growing population. As a finite resource and a fundamental for life, water sits at the heart of the debate. Indications are that the consumer is beginning to understand this and that water looks set to be the next big environmental issue to capture the public imagination.

A recent partnership between National Geographic Society, the Nature Conservancy and WWF has puts its efforts into educating the consumer about their water footprints, with an emphasis on where their food and other consumer goods come from, and how much water is required in those places. It has also sought to inform consumers about water scarcity and its implications for business, local communities and freshwater ecosystems.

So the pressure is now beginning to be applied to business, especially those with significant water impacts. Credit, then, to some high profile consumer facing companies such as Coca-Cola who were present in Stockholm and engaging with the water experts on the measures that they're applying in sustainable water management.

Coca-Cola, a global product which has a high water content, has demonstrated some leadership in putting water at the heart of its sustainability strategy and establishing a so-called global water stewardship programme which, since 2004, has seen an almost 20% reduction in water usage. Companies such as Coca-Cola which innovate not only to reduce their water consumption but also the water footprint of its products will be best placed to face the consumer and regulatory front.

Corporate effort to reduce carbon footprints appears to be having some effect, in the developed world at least. Business now needs to look at what lessons it learnt from that process and apply informed thinking on how to manage its water footprint. It may not be an entirely flawless approach, but the water footprint will serve as another stepping stone to a more holistic view and understanding of our total impact upon the environment.