Everything You Know About Water Conservation Is Wrong

Forget short showers. Worry about the 6,340 gallons of "virtual water" in your leather bag.

By Thomas M. Kostigen|Wednesday, May 28, 2008

I’ve been mindful of the amount of water I use when making a pot of coffee ever since learning that one-third of the tap water used for drinking in North America is actually used to brew our daily cups of joe—and that if each of us avoided wasting just one cupful of coffee a day, we could save enough water over the course of a year to provide two gallons to every one of the more than 1.1 billion people who don’t have access to freshwater at all.

That is a stark statistic, when as many as 5 million people die unnecessarily each year because of lack of water and water-related illnesses; one-third are under age 5.

So for me that excess cold coffee at the bottom of the pot became a bothersome reminder. But I had never thought beyond that—about how much water it takes to actually grow the coffee. That amount is called virtual water (pdf), and it’s the kind of thing you don’t really consider until someone brings it to your attention: “Do you know how much water it took to make this?” Virtual water is a calculation of the water needed for the production of any product from start to finish.

Here’s how it is figured: It takes about 155 gallons of water on average to grow a pound of wheat. So the virtual water of this pound of wheat is 155 gallons. For a pound of meat, the virtual water is 5 to 10 times higher. There’s a virtual water count for everything. The virtual water footprint of a cup of coffee is 37 gallons; an apple, 19 gallons; a banana, 27; a slice of bread, 10; a sheet of paper, 3; and a pair of leather shoes, 4,400, according to Waterfootprint.org, a Unesco-run Web site providing a calculator for individual and national water use. In fact, virtual water in internationally traded food and products such as these accounts for 15 percent of global water consumption.

Virtual water matters a lot these days because we are in an encroaching global water crisis. According to the United Nations Environment Programme, the world needs to increase its water supply (pdf) for irrigation by 14 to 17 percent by 2030 just to meet its dietary needs. Virtual water is where major savings can accrue.

Proper management and use of the world’s virtual water already save almost 5 percent of the water used annually in global agricultural production, according to Unesco. This follows a simple logic: Places with less water gain access to foods with high water requirements by importing them from areas with high rainfall or substantial water supplies. This allows water-scarce regions to use their own water resources more efficiently for other purposes—and create water savings. For instance, areas of southern China that have more water and are better equipped to grow certain water-intensive agricultural products can send them to northern China. This frees up northern water supplies for other uses, such as drinking and sanitation. Jordan saves 60 to 90 percent of its domestic water supply by importing water-intensive products.

The water savings are even greater than they seem at first. Producing grain and other foods in an arid country like Jordan may require two or three times the water it takes in humid settings in South America or the United States. So the virtual water saved may be three times the amount that was actually necessary to grow the crop in a more appropriate climate. It’s all about being smart with water.

Yet we can be smarter, and need to be.

Right now we lose 30 to 50 percent of the food we grow—and all the virtual water in it—by the time it is ready for consumption, says Daniel Zimmer, executive director of the World Water Council (WWC) in Marseille, France. These losses come in harvesting, production, processing, transportation, and storage. Tossing out leftovers wastes every drop of water it took to grow the food (and think of all the times you don’t ask for a doggie bag). Indeed, the third most common refuse found in landfills is food, according to the Environmental Protection Agency. “Sure, a few liters of water are saved when you take a shorter shower,” Zimmer says. “But hundreds of liters of water are lost when you throw away food. We have to begin to think about our water use differently.”

I like the idea of virtual water because it helps us think about our water use differently without having to make giant, complicated leaps. It puts water into the context it deserves: We use freshwater mostly for agriculture, not for drinking or bathing. Today agriculture accounts for about 70 percent of all water use in the world and up to 95 percent in several developing countries. So it makes sense to first start looking at savings via food production. And when I say savings, I mean efficiencies and better water management, not necessarily avoiding particular food groups altogether—although that isn’t such a bad idea once in a while either. Meat requires 5 to 10 times more water to produce than vegetables do. Swap the two in your diet and you will save up to 750 gallons of water a day. (See “What’s Your Virtual Water IQ?” page 26.)

While thinking about water differently should be a moral imperative, in a world view it comes with controversy. “At the global level, virtual water and the trading of it has geopolitical implications,” the WWC says in a report on the subject (pdf). “It induces dependencies between countries....This can be regarded either as a stimulant for cooperation or as a reason for potential conflict.”

Right now the United States is a water exporter, but population growth, pollution, and lingering drought in vast regions may change that. “As demand grows we are going to have to ask what is it being used for and whether that is a good use of our water,” says Maude Barlow, cofounder of the Blue Planet Project. “One-third of the water in the United States is exported as virtual water when a number of major water systems in the United States are in a catastrophic decline. People may begin to say, ‘Why are we shipping our water away?’”

Dominant virtual water exporters in addition to the United States are Canada, Australia, Argentina, and Thailand. Countries with a large net import of virtual water are Japan, Sri Lanka, Italy, South Korea, and the Netherlands. Based on estimated global virtual water trade flows, national virtual water trade balances can be drafted, but getting countries to agree on creating a fair market for water isn’t easy. “Trade arrangements, access to markets, finance, and foreign exchange must all be taken into account,” the WWC says in its report. For poorer countries those are big obstacles.

International companies are also being pitted against one another because of water shortages and competition for existing resources. The food industry, for example, may end up fighting the biofuel industry for access to arable land as the world runs short of water, warns Peter Brabeck, Nestlé’s chairman and chief executive. “We will not find sufficient water to produce all the crops,” he told the Financial Times in February. “There will be a fierce fight for arable land.” But that doesn’t have to be the case.

“Companies like Coca-Cola, Nestlé, and many others particularly like the water footprint concept,” says Arjen Hoekstra, professor of multidisciplinary water management at the University of Twente in the Netherlands. He notes that because many businesses depend on water as a major component for their products, it’s in their best interests to ensure supplies are plentiful to avoid the potential conflicts. “Some companies see the business risks attached to water scarcity and seriously look into how to reduce and offset their water footprint,” Hoekstra adds.

In the end, though, water parity and more supply will come only through increased awareness among individuals, as they will drive the larger interests. “It’s really about education and getting people to see their own water use and their water footprint; we think that is the first step in conservation,” says Scott Cullen, executive director of the nonprofit group Grace (Grass Roots Action Center for the Environment). Along with Food & Water Watch, the Interfaith Center on Corporate Responsibility, and the Johns Hopkins Center for a Livable Future, Grace has developed a water footprint calculator for a joint program, H2Oconserve.org. Initiatives such as this may lead to further developments, such as labeling the water content of products. This, in turn, may lead to even more water-conscious decision making. “Tastes Great…Less Filling…Less Water”—that type of thinking.

It’s time to ask how we can make better use of our water supplies so that virtual water doesn’t remain the ethereal concept its name suggests. It can be a far bigger source of real-world savings. For my part, I now note waste in different forms. I try to plan or order meals more accurately so I don’t have leftovers, and I try to eat lower down the food chain. In short, I try to do what my mother told me as a child—“Eat your vegetables”—because I now know what went into making them: a lot of water.

Our Very Wet Footprint
The average person on earth has a virtual water footprint of about 328,410 gallons each year; that includes everything used to make the food, clothing, and other water-driven products we consume. In China the average footprint is only 185,412 gallons, while in the United States it is 656,012—the largest on the planet. DISCOVER staffers Missy Adams and Corey Powell measured their water footprints using a questionnaire at Waterfootprint.org (and you can too). Questions ranged from how many showers they take each week to whether the water runs while they brush their teeth; from their food preferences to their income.

Research Editor Missy Adams has a relatively small footprint (see chart below), in part because she’s light on the laundry and quick with a shower and has a diet driven by vegetables, fruits, and sweets.

Executive Editor Corey Powell likes meat in his takeout, and you’re sure to find chicken breasts and beef in his freezer—something to cook up while he’s watering his garden or hosing off his sidewalk in Brooklyn.


VIRTUAL WATER USAGE (annual average per person, in gallons)

World 328,410
United States 656,012
Missy Adams 469,792
Corey Powell 1,047,437
To determine your own virtual water footprint, go to waterfootprint.org.

Where’s the Water
There are 10,460 cubic miles of freshwater available on the planet as a resource each year, and the breakdown of worldwide access to it just isn’t equal. But understanding who has the good stuff and who is in need can allow us to maximize commerce in virtual water, helping balance things out. For instance, Kuwait has essentially no freshwater; its residents live off desalinated seawater, which doesn’t count as a direct resource. South America, on the other hand, has an enormous surplus of freshwater due to rainfall and its ecosystem, so it is a great exporter of virtual water. Source: Worldmapper.org. (All percentages are estimates.)

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