The issue of water scarcity has been creeping up the corporate agenda for some time. Nestlé chairman Peter Brabeck-Letmathe has claimed that water will run out before oil, while Sainsbury's chief Justin King used this year's City Food Lecture to highlight water as potentially the biggest environmental concern facing the food industry.
In a survey of UK-based fresh produce, meat and bakery processors, 80% said water scarcity could have a significant impact on their business. Many manufacturers are already responding to the challenges ahead.
Walkers Crisps' owner PepsiCo, for instance, is perfecting a technology to 'harvest' the water lost when potatoes are cooked, re-using it to clean, peel and slice them when they enter the plant. Greenvale has ploughed over £1M into a new 'cascade' system for washing the 5,500t of spuds it uses each week. It has cut consumption of water from 750l to 120l a tonne and is being introduced at two other sites.
However, the likes of Greenvale and PepsiCo know this is not where the story ends: the big savings will come at the production level where water use and risks are often greatest.
Take soft drinks. Many firms have set targets to use 2.2l of water per litre of soft drink. Two Degrees supply chain manager Izabela Stacewicz says that's a "good effort" but it's important to think strategically. "If the drink is sweetened by cane sugar then 150250l of water are used." This has an impact on the overall footprint.
Producing food is thirsty work: about 85% of our water footprint is from the consumption of agricultural products. By 2030, demand for water is expected to outstrip supply by 40%. "We're already tipping from 'serious' to 'business-critical'," explains Dan Crossley, a principal sustainability adviser with Forum for the Future. "That's why we're seeing [more firms] taking the issue of embedded water [all the water used to produce, retail and consume their products] very seriously indeed."
PepsiCo has set a '50 in 5' target, in which it is working with supplier farms in water-stressed regions to reduce the impact of applied water by 50% in five years. Unilever estimates that half its water impact is accounted for by the production of raw materials; work with tomato growers in California has already doubled yields through varietal selection and drip irrigation.
Many more firms may look closely at farm-level water use. After all, crop failure can create sudden fluctuations in commodity prices, or the need to source more crops at short notice both of which affect profit.
Assessing water risks, let alone water footprints, is not always easy especially for those buying on the commodity markets. But that doesn't mean traders shouldn't be asked questions, says Two Degrees' Stacewicz. Food and Drink Federation director of sustainability Andrew Kuyk agrees, adding: "You need to be aware of what you are buying, where it is from and what impact it has locally. Questions need to be asked."
In some areas, pressures are already acute. Innocent has confronted issues with suppliers of strawberries in Spain where demands from farmers and an adjacent national park are putting strain on a vast underground aquifer. Ingredients manager Rozanne Davis says Innocent is collecting data on water and looking to optimise the use of the resources available. "We've created a dialogue where before there was only negativity and conflict," she adds.
Even in the UK, competition will intensify. Already the drought has caused concern for this year's potato harvest. Long-term fears also exist. Nestlé, for example, 'footprinted' its Bitesize Shredded Wheat cereal following concerns that the farms growing its wheat and factories processing its cereals were located where water levels were decreasing and the population was set to rise by 30%.
Challenges will come and food firms will need a better understanding of the water embedded in their products. Without it, where would they be?