Not a drop to drink

Pointing out that it takes 800 gallons of water to make one hamburger, a British writer argues that water shortage is the "defining crisis" of our time.

By Katharine Mieszkowski

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April 25, 2006 | Leave the tap running while brushing your teeth, and you're dumping four and a half gallons of water down the drain, according to the U.S. Environmental Protection Agency.

That's the kind of shiny stat trotted out to inspire profligate water-wasters to conserve. Just shut off the tap, save water. It's easy! Huzzah! Yet, as British science journalist Fred Pearce makes crystal clear in "When the Rivers Run Dry," the water we consume -- and waste -- in everyday life is hardly limited to what comes out of our own faucets.

Pearce, a longtime editor for New Scientist, who is now an environmental consultant for the magazine, calculates that it takes 40 gallons of water to grow the ingredients for the bread in a single sandwich, not to mention 265 gallons to produce a glass of milk and 800 gallons for a hamburger. And that's just what's for lunch. Don't get him started on what you wear to this water-rich feast. Even a simple cotton T-shirt bearing some hopeful green slogan like "Save the Bay" is a huge water user. Pearce figures it takes 25 bathtubs-full of water to grow the scant 9 ounces of cotton for such a shirt.

Water is the ultimate renewable resource, literally falling from the sky back to earth after it evaporates. And since it's so heavy and cumbersome to move great distances, it's also a local resource. Yet, start quantifying the water embedded in foods and goods, the "virtual water" as economists call it, and water is fast becoming a global commodity like oil. There's Brazilian water in the coffee beans grown for an American latte; there's Pakistani water in the cotton in that T-shirt.

In "When the Rivers Run Dry," Pearce finds a growing strain on many local water resources around the globe, as the world's population grows. As he visits dozens of countries, he sees rivers that have been so diverted, depleted and dried out, such as the Rio Grande, that they no longer conform to their original map locations. Pearce reports that the fallout from the competition for water resources is enormous, exacerbating tensions between Palestinians and Israelis in the West Bank and even accidentally poisoning villagers by the millions in India and Bangladesh.

Yet, Pearce also finds hope in the way some communities around the world are harvesting and using water. Salon spoke with the writer by phone from England about why he thinks we need a "blue revolution."

If there are 650 gallons of water in a pound of cheddar cheese, is it futile to make small gestures like turning off the water when you brush your teeth in the name of saving it?

It helps with water bills, so it makes sense in that way. And it may make sense with local water resources, which may be constrained, just within a small town, or even a community.

At the global scale, no, it doesn't make much difference. Most of the water that each one of us uses comes from the water used to irrigate the crops that we consume. That's principally food, but not only. Cotton for our clothing is a major user of water around the world.

We don't really know as we pick up the food from the store whether our purchases are responsible for making some local crisis elsewhere worse, but it is often the case. Many countries are facing serious water shortages; often their rivers are running dry, or their water tables falling very fast, and in many cases much of that water is being exported by those countries in the form of goods. Yet, when we pay market price for those goods, that price doesn't usually include any estimate of the cost to the water resources. We still think of water as an unlimited resource rather like the air we breathe.

Now some countries are entirely dependent on water from elsewhere to feed their people, on this "virtual water."

Many countries have run out of water for growing their own crops and are now importing water in the form of food. Egypt really, for instance, lost the ability to feed itself perhaps 30 years ago. It now imports a large amount of water in the form of food. That is the only way it can do it. Water is pretty heavy stuff to move, but the trade in products produced with water is huge, and in many ways can be seen as a trade in water.

What are some of the rivers around the world that have run dry, or are most in danger of it?

There are two rivers in a bad way in the U.S., one of which is the Colorado. There's a U.S. treaty with Mexico to deliver water over the border, and the U.S. has considerable difficulty in providing any water over the border to meet its minimum treaty requirement, because all the water is used up essentially by farmers and increasingly by cities along the Colorado.

The water goes off to Southern California, Phoenix, Tucson [Ariz.]. By the time the river crosses the border into Mexico, which is close to its delta, it is really very dry. There's not a lot of water left.

The Rio Grande is another interesting example. It essentially dries up about a thousand kilometers from the sea near El Paso [Texas]. The riverbed is virtually dry for 300 kilometers before some more water comes back in from tributaries coming in from Mexico.

So, whatever it looks like on the map, really the Rio Grande is two rivers. There's a river that gives out at El Paso, and there's the tributary that comes in and replenishes the last run to the Gulf of Mexico. There are very serious economic repercussions from the drying up of the Rio Grande. I met farmers who simply no longer have water to irrigate their crops, and that's on both sides of the border, on the Mexican side and on the Texas side.

If you look around the world, virtually no water flows from the Nile into the Mediterranean; very little water flows from the Indus through Pakistan into the Arabian Sea; the Yellow River in Northern China, one of the world's longest rivers, is essentially dry for much of the year. A little flow goes down to the sea, but very little. So, this is close to becoming a global phenomenon, some of the world's largest rivers, and longest rivers, simply not reaching the sea.

One response to rivers running dry is to move water enormous distances, at the cost of hundreds of billions of dollars. What do you make of such grand projects?

There are plans now for huge transfers of water across some of the world's biggest, most densely populated countries in order to provide water for the new mega-cities, and for farming. China's got one of the largest, and that's going to take a large amount of water out of the River Yangtze, which runs through the south of the country, and deliver it into the northern plains, to the Yellow River, which has essentially run dry for much of its course.

Essentially, the Yangtze is going to replenish the waters of the north of China. This project is already underway. Two of the three branches that are planned are already under construction. China hopes to be delivering water from the Yangtze to Beijing in time for the Olympics in 2008. This project will probably cost something like $60 billion. It's a major enterprise in order to keep northern China from running dry. India has talked about something even larger.

Yet, in these vast projects to move water around, aren't incredible amounts of the water lost through evaporation or seepage from canals?

Many large engineering projects suffer from a huge range of inefficiencies, which is why -- in general -- I'm not in favor of them. It's much better to do things locally, because you can control the water more. One thing that surprised me greatly was discovering that with Lake Nasser behind the Aswan High Dam in Egypt -- one of the world's kind of totemic dams -- that the evaporation from the reservoir behind that dam annually amounts to, in metric, 15 cubic kilometers of water [3.6 cubic miles], if you can imagine a vast amount like that.

That is roughly the amount of water that is used by the whole of the United Kingdom in a year. In other words, you could fill every tap, meet every water demand in the U.K., a country of more than 50 million people, simply by the water that evaporates from the surface behind the Aswan Dam.

Now, that's an amazing statistic, but there are other reservoirs that lose similar amounts of water, especially in the hot tropical regions. That can't make much sense, if you have a country which is desperately short of water, and desperately trying to collect it up to deliver it to farmers. There are also huge evaporation rates from some of the distribution canals. Also, seepage from beneath distribution canals can be a major loss of water.

Next page: What water has to do with the Israeli-Palestinian conflict