Look around you: at home, in the office, on the train, in the cafe… Almost everything you see took significant amounts of water to produce, source or transport. We depend on this precious resource for our health, our food, our infrastructure and industry. But until now, we've taken its abundant supply for granted, and paid very little for the privilege.
These days of plenty will soon be over. Consultants McKinsey predict that by 2030 global water requirements will have grown from 4,500 billion m3 today to 6,900 billion m3. Such a hike means demand will exceed our current reliable and accessible supplies by 40%. And these are becoming increasingly unreliable as climate change kicks in.
So who will feel the pinch? The answer's simple: we all will – and not just because of headline-hitting drought. Supply chains for everything are at risk: from food to clothing, from cosmetics to concrete. Heavy industry needs water pressure to slice through steel; data warehouses need a constant flow to keep the servers cool.
This isn't just a problem for the future. Droughts across the world's cotton belt triggered price rises that slashed the margins for high street retailers. The recent Russian dry spell led to export bans and historic highs in the price of wheat. Nestlé's Chairman has gone so far as to suggest that there's a greater risk of running out of water before oil.
Last year, the Carbon Disclosure Project (CDP) asked 302 of the world's largest companies – mostly in food and drink, tobacco, metals and mining – how significant a concern water is to them. Over two thirds replied that they were already facing problems including water shortages and rising prices for extraction. Many are taking action to cut consumption, setting goals and reporting against performance. But this looming crisis is demanding something more rigorous than the watery equivalent of energy targets.
"It's beginning to dawn on companies that the supply could dry up", says CDP's Head of Water, Marcus Norton. "They want to get a handle on the risks, not only within their own operations, but up and down their supply chains."
Hence the growing interest in comprehensive 'water footprinting'. It's not an entirely new concept. It was first used in 2003 to calculate annual average water consumption per head, across a range of countries. Yemen had the smallest, at 619m3; the US topped the chart at 2,483m3. No surprises there. Then research shifted from countries to consumer goods, and the picture got more intriguing. We discovered that the average cup of coffee takes 140 litres to produce; an apple 70, and an egg 200 – mostly for feeding the hens. But one of the most detailed studies assessed the water footprint of … beer.
In 2009, a report by WWF and SABMiller found that it takes 155 litres of water to make just one litre of beer – in South Africa. If you're brewing in the Czech Republic, though, the footprint is just 45 litres. But before you reach for the Pilsner, there's a catch: when it comes to water, size isn't the be-all and end-all. This is what makes water footprinting a good deal more complex than its carbon equivalent, where it's a simple case of the smaller the better.
"The big difference is that carbon is a global concern, whereas water is a very local one", explains Rob Lillywhite, a senior research fellow at the University of Warwick. A kilogram of CO2 emitted in Spain has exactly the same effect on the atmosphere as one emitted in New Zealand. But with water, the impact depends on the degree of water scarcity in the area it's taken from."
Much as SABMiller found. The company has also mapped its water footprint in Peru, Tanzania and Ukraine, and identified different totals – and challenges – in each location. Even within South Africa, footprints varied. Barley grown in the hot and arid Northern Cape, and maize in the flat grasslands of the North West province, depend largely on irrigation using groundwater (known in footprinting terminology as 'blue' water). But in the Southern Cape and Mpumalanga province, there's enough rainfall to quench the same crops with 'green' (rain) water.
Elsewhere, it's a different story. Take lamb. Cranfield University calculated that the production of a kilo of English lamb requires over 50,000 litres of water. On the surface, that sounds hopelessly unsustainable, and should be enough to put you off kebabs for life. But a whopping 96.6% of it is 'green' water. Many lambs graze rain- fed grasslands where water scarcity isn't a problem, which means, says Cranfield, that the actual hydrological impact of English lamb production is "very small".
If location can make all the difference, so can timing. It's one thing to take 100 litres from the ground in Suffolk, say, when it's still soaking up the spring showers. Go back in the height of summer, when the water table is much lower, and it's another story. The same applies with bells on in a country like India, where using a thousand litres of water at the height of the monsoon has a dramatically different impact than it would during the dry season.
So when it comes to working out the water footprint of a product or activity, a single figure doesn't cut it. As Andy Wales, Global Head of Sustainable Development at SABMiller, puts it, "a water footprint is much more than just a number". It's a story, fleshed out with when, where and how.
But conveying this level of detail to stakeholders, from the consumer to the business strategist, presents a challenge. It's a lot to squeeze into a single label, let alone a single figure – which is what a wave of eye-catching statistics have led many to expect. WWF-UK's water footprint expert, Ashok Chapagain, admits these headline figures (some of which he had a hand in calculating) are great for raising awareness about the extent to which water is embedded in our lives, but not helpful as a basis for decision making. He says businesses need to look behind the numbers, and into the detail: "That's where the really great data is."
When SAB Ltd, the South African franchise, mapped the water use of its crops onto local availability, it found that the North West has sufficient resources to support the maize production, despite its dependence on irrigated water. More vulnerable, according to the study, is barley growing in the Southern Cape. There's doubt as to whether, with a changing climate and growing population, there'll be enough rainfall to meet future demand. So in this particular case 'blue' water is better than 'green'.
Overall, agriculture takes the lion's share of water at 85%, compared to 10% for industry and just 5% in the home. So it's no surprise that much of the early work on water footprinting has involved food and drinks companies. Smart players, though, are finding ways to cut water use right across their footprint. Take PepsiCo, owners of Walker's crisps. First it cut use out in the fields; now it's harvesting water lost in the cooking process, and using it to clean, peel and slice the potatoes as they enter the plant. Spuds can be up to 80% water, most of which evaporates to give the crisps their crunch. Simply by placing cold lids above the steam to capture condensation, and installing filters in the waste pipes, PepsiCo can harvest over 3,000 litres of clean water an hour. It really can be as simple as that.
For other companies, the end user is where the action is – or rather, needs to be. When Aquafresh toothpaste makers GSK commissioned a water footprint tool to identify potential savings, they came up with a surprise: no less than 99.7% of the toothpaste's footprint comes right at the end of the chain – when people brush their teeth – largely because they leave the tap running. It was an area completely outside GSK's control. Not to be deterred, the company launched a 'Chiudi Il Rubinetto' (switch off the tap) campaign in Italy, an area where domestic water supply could be at risk in the future.
"It's one of the few examples of an FMCG company marketing to its customers around water use", says David Symons, a director of consultants WSP, which carried out the footprinting work for GSK. "What's more, it's an example of how to take an academic concept [water footprinting] and apply it to your business."
Persuading consumers to change behaviour – even in the simplest of areas – can be an uphill struggle. So what about developing products that do the job for you? That's the thinking behind a new concept for a 'waterless' washing machine, which uses nylon beads as cleansing agents, cutting water use by 90%. Designed by Leeds-based Xeros, this hit the spotlight a year ago when it was listed by WWF as a 'green game changer'. But despite the ubiquity of dry cleaners on the high street, the public have so far struggled to accept a domestic washing machine that doesn't need water.
A less revolutionary approach adopted by Unilever may have more success. "We can't tell women to have shorter showers, but we can develop hair conditioners that don't take so long to rinse out," says the company's Environmental Sustainability Director, John Temple. Unilever, which makes household brands such as Dove, Persil and Timotei, has already brought a new conditioner to the Indian market, albeit one used on clothes; it requires a third less water to rinse out. In a country that is water stressed, the potential environmental impact could be significant, but there is a social benefit too: less water means less time spent fetching and carrying it, a laborious chore which can keep children from attending school and women out of employment.
Unilever was able to identify this opportunity thanks to an expansive footprinting exercise – work that has, says Temple, proved "a fabulous resource for R&D and spotting new opportunities". The company footprinted 1,600 of its products based on the metrics of waste, carbon and water. Temple says carbon is pretty straightforward, but with water "it's a steep learning curve. However, if you take a pragmatic approach then it can be a very useful exercise."
While the approach must be pragmatic, the results can throw up a few surprises – or 'outliers', as statisticians like to call them. Without water footprinting, whoever would have known that Turkish people are the "pre-wash champions of Europe" with 44% indulging compared to the 7% EU average. But when Turks do their laundry, the study found, they also tend to under-fill their machines. As a result, this water- stressed country is consuming 30% more to clean clothes than the global average. With a well-known brand, Omo, already established in the market, Unilever had the scope to help change that.
"We ran a big PR campaign with WWF to highlight good laundry habits, stop pre- washing [because it wastes water and energy] and reassure people that Omo washes brilliantly without [it]," says Temple. "Life cycle measurements like [water footprinting] allow you to spot these outliers and work on approaches to tackle them." That isn't always easy, he adds. "Trying to reduce our impacts at the consumption end is the biggest challenge we face. But, if we can encourage people to use different products that consume less water then we can make a real difference."
Changing consumer behaviour is one possibility, but some are looking to water footprinting as a means of changing entire sectors. Balfour Beatty, the construction company, is one of a handful of those outside the food and drink industry who have jumped in with both feet. The infrastructure group is working with consultants Parsons Brinckerhoff to develop a water footprint tool for both its internal operations and a variety of construction products. This will mark a shift in direction for water footprinting which, to date, has been most useful to manufacturers. "It'll enable us to look at the design of a project, and the materials we are using, and determine whether there's a way of reducing the water impacts 'by design'," explains Lynne Ceeney, PB Head of Sustainability for Europe and Africa. "No one has done anything like this on this scale in construction before."
Ceeney admits there is a plethora of issues to understand, but there's no chance of anything being swept under the carpet. "There's a risk that we could end up spotlighting water-intensive products that are being sourced from water scarce areas, but we need to deal with that. We're not doing this so we can strike products off a list, but so we can get a better picture of where the risks are in our [work] and the construction industry more widely, and what we can do about them."
Eventually Ceeney would like to have a database where companies can compare products. "It won't be possible to [do a direct comparison] of every product", she admits, "but at least we'll be able to see the emerging patterns in the supply chains and where the risks are. For instance, do we bring dry or wet product to a site, and how does that affect the other impacts like carbon?"
In the eight years since Professor Hoekstra introduced the concept of water footprinting, the science has come a long way. Corporate attitudes towards water scarcity have changed over that time, too, with some businesses already facing risks. However, the marriage of scientific advancement and business requirement can be a complex one – and nowhere is this more apparent than for water footprinting.
The organisation charged with 'counselling' that relationship is the Water Footprint Network, a collaboration of businesses and scientists. It's just published its 'state of the art' manual which, says Executive Director Ruth Mathews, should help companies understand in more detail what their water use is, and guide them to take the most significant steps toward good water stewardship.
The likes of SABMiller, PepsiCo and Unilever are already on the journey, while others, like Balfour, are just setting out. Many more will be keeping a close on water footprinting going forward, says Stuart Orr, Freshwater Manager at WWF International. "We will all need to do a better job of accounting for our water. To set targets and benchmarks, to show best practice, to anticipate consumer trends, to answer investor questions and to adhere to regulatory frameworks and laws. In all these cases a water footprint is relevant."
Plastic less drastic: one company's journey to put footprints into practice
It's the food and drink businesses that have led the way on water footprinting – indeed the methodology is very much biased towards the sector. Now, others are catching the wave.
Swedish plastics manufacturer Borealis is one. It's recognised that the footprint of the materials it's developed use in water and sewage pipe systems is considerable. About 17 million m3 a year, to be precise.
It isn't the most water-intensive operation in the world, but Borealis knew that water was becoming a hot topic and felt there was sufficient need to look at any risks. "If we build a plant it'll be there for 30 years, so we want to know that in 30 years' time we'll still be able to run operations from that plant," explains European Affairs Director, Sylvain Lhote. "We'd identified water as an issue some time ago, and we'd been following the progress with water footprinting, so we wondered: 'Could it work for us?' Could it help us fill some of the gaps we had in the knowledge of our operations and our supply chain?"
So, in 2008, Borealis offered itself up as a "happy guinea pig" to the Royal Institute of Technology in Sweden (KTH) for an experiment that would result in the first ever water footprint assessment of plastics. Using WFN guidelines, they embarked on a detailed pilot study of the most prosaic of products: a polyethylene crosslinked (PEX)
pipe plumbing system for a 100m² apartment. It's hardly stuff to set the heart racing, but it helped Borealis and KTH sort through various methodological challenges and data gaps, and distinguish between direct and indirect impacts.
"We found our direct water footprint to be quite low – ranging from 1.2 to 6.5 litres of fresh water per kilo of finished product," says Lhote. "But the indirect footprint originating from feedstock can triple the figure. So we're looking at about 4m3/tonne of finished product (or 17 million m3 a year in all). But that doesn't tell us much at all – now we need to relate the data to the local level."
That's the complicated bit. Borealis has now drawn up a range of guidelines looking at water availability, quality, risk, flow and discharge at seven of its manufacturing sites. Later this year, it should be in a position to define what the sustainable management of water might look like for the company, site by site. And that's the level at which it has to operate, if the exercise is to have any meaning. "Unlike the case of carbon emissions, we can't just give every plant a set figure and tell them to cut water by that amount."
The company is already taking actions on some of the findings. On one Belgian site, for instance, where water stress has been identified, a drainage water recovery project is helping to reduce ground water use by 30%. Other applications are sure to follow. It's also still relatively early days for water footprinting as such, though, and Lhote cautions that there is a long way to go before it proves powerful in practice as it does in theory.
David Burrows is a freelance writer