The report found that the total water footprint of the UK is 102 Gm3 (billion cubic metres) per year. That works out as roughly 4, 645 litres per person per day!!
While on average a single person in the UK goes through 150 litres of water a day by drinking, flushing and washing, around 30 times that amount is consumed by ‘virtual’ water – the water embedded in the food we eat, the clothes we wear and the numerous other items we consume. This is equivalent to someone having 58 baths or washing their clothes 75 times in a single day.
Virtual water refers to the volume of water required to produce a product. For example it takes 2,900 litres to ‘grow’ a cotton shirt. As WWF say: "A water footprint is the total virtual water content of products consumed by an individual, town or country. A water footprint consists of two parts: the use of local water and the use of global water resources. The water used can be divided into blue water (water taken from ground or surface water resources), green water (water evaporated from soil moisture supplemented by rainfall) and grey water (defined in the WWF report as the amount of water rendered unusable by agricultural inputs, e.g. fertilisers). Concluding that the UK is the sixth largest importer of water in the world, the report brings into sharp focus the dependency of UK lifestyles upon water imported from other nations."
This means that only 38 per cent of the UK’s total water use comes from our own rivers, lakes and groundwater reserves. The rest is taken from water bodies from across the globe to irrigate and process food and fibre crops that people in Britain subsequently consume. This is worrying in that huge amounts of these products are grown in drier areas of the world where water resources are either already stressed or very likely to become so in the near future.
It is great to see WWF highlighting this issue as too little has been done to see what impact climate change, population growth and increased energy costs will have on all this - we are long overdue a time when governments, businesses and individuals should be considering their water footprints and improve currently managed water systems, especially in places where water is scarce. See my recent letter to press here - and that doesn't even begin to consider virtual water.
Meanwhile Lester R. Brown o the Earth Policy Institute, also writes last month on the need to raise water productivity (see here). He notes that worldwide, average irrigation water productivity is now roughly 1 kilogram of grain per ton of water used - it is not surprising that 70 percent of world water use is devoted to irrigation and therefore the need to raise irrigation efficiency is key to raising water productivity overall. As he notes: "Raising irrigation water efficiency typically means shifting from the less efficient flood or furrow system to overhead sprinklers or drip irrigation, the gold standard of irrigation efficiency. Switching from flood or furrow to low-pressure sprinkler systems reduces water use by an estimated 30 percent, while switching to drip irrigation typically cuts water use in half...."
He goes onto conclude: "What is needed now is a new mindset, a new way of thinking about water use. For example, shifting to more water-efficient crops wherever possible boosts water productivity. Rice production is being phased out around Beijing because rice is such a thirsty crop. Egypt also restricts rice production....For people consuming unhealthy amounts of livestock products, moving down the food chain reduces water use." Check your water footprint
He writes about eating less meat and the impact that could have on water use and goes on to mention other measures. However more could be said about the consumption of all goods and the size of their water footprint. It is time we became aware that more than three fifths of the water we use is imported and started to take more actions
Check your water footprintLastly a good article looking at last years floods and how water came to the Cotswolds - see London Review of Books: www.lrb.co.uk/v30/n15/meek01_.html