In Maine, officials worried about the increase in forest and grass fires. In Massachusetts, paddlers encountered gravel and sandbars in formerly passable river stretches. New Jersey residents had to limit their water usage as reservoir levels plummeted, and farmers in Virginia watched wheat and soy crops wither.

This year's searing Northeast summer landed much of the region in or near drought conditions, and offered a stark reminder of a reality people around the world face every day: water scarcity.

DID YOU KNOW?

Low-flow toilets are great, but household uses represent just 5 percent of the water you consume—the rest is known as hidden or "virtual" water. Check out how much water it takes to produce these common items. Sheet of paper, 2.5 gallons Computer microchip, 8.5 gallons Gallon of gas, 13 gallons Cup of coffee, 37 gallons Cotton T-shirt, 713 gallons Pair of leather shoes, 2,113 gallons Car, 39,000 gallons Sources: Water Footprint Network, Circle of Blue, National Geographic, Marketwatch

According to the U.N.'s Food and Agriculture Organization, water use increased at more than twice the rate of population growth over the last century. Today, 1.1 billion people lack enough water to meet their basic needs. This bleak situation is compounded by climate change, which experts say will only make things worse down the road; in fact, a recent study commissioned by the Natural Resources Defense Council says water supplies in 70 percent of all U.S. counties could face risks from climate change by 2050.

So what can be done to protect this precious resource? Efforts range from legislation to irrigation to conservation. But none of that will succeed without public awareness and action. Enter the tool that promises to make consumers, corporations, and entire nations aware of their true impacts: the water footprint.

What’s a Water Footprint?
Simply put, a water footprint tells you how much water you use—not just the gallons that flow from your faucets, but the "hidden" ones found in everything from food to clothes to energy sources. Take the typical hamburger: When you consider beef production inputs, your meaty indulgence represents a whopping 634 gallons of water. (See sidebar for more examples.)

Similar to the more widely known concept of a carbon footprint, the water footprint is intended as a tool for raising awareness and inspiring conservation. Created in 2002 by Dutch professor Arjen Hoekstra, the model found a permanent home in 2008 when an international coalition of institutions, companies, and government agencies created the Water Footprint Network.

"The water footprint [concept] shows how integral water is to everything we do," says Kai Olson-Sawyer of H2O Conserve, a New York-based program that also launched in 2008 and recently joined the Water Footprint Network. "We have to start thinking more about this issue, because water is crucial to our future."

While the water footprint can be an eye-opener for individuals, it also offers a broader look at consumption habits around the world. The American lifestyle, for instance, requires about 1,800 gallons of water a day, according to the Water Footprint Network; that's twice the global average, and three times the smallest footprint, found in Yemen.

Besides allowing individuals and countries to compare notes, the water footprint can be a useful business tool. As Olson-Sawyer and others point out, there are major economic implications at stake; Fortune magazine has called water "a precious commodity that determines the wealth of nations," and the Associated Press reports that "high-tech companies, farms, and soda bottlers have lost millions because they didn't foresee the risks posed by droughts and floods tied to global warming."

Now the water-footprint notion has been embraced by major corporations including Coca-Cola, Unilever, and Starbucks, and it's gained such currency that advocates have suggested it become a product label similar to the Energy Star label. But critics say there's a long way to go before that's even possible. For one thing, the current model does not factor in where the water used to grow and manufacture products originates—in wet climates, a gallon of water means something quite different than it does in the desert. Furthermore, critics say, the concept needs to be standardized in order to be effective. Much like the carbon market, the many variables at play mean interpretations and information can differ.

Close to Home
Still, the fact that the water footprint is becoming more common is welcome news to its proponents. They hope it will provide the inspiration people need to think more carefully about the water that sustains us, around the world and here at home.

In the mid-Atlantic Highlands, for instance, water is a crucial issue, says Mark Zakutansky, AMC's Pennsylvania Highlands coordinator. The 3.5 million-acre region, which stretches through Connecticut, New York, New Jersey, and Pennsylvania, provides drinking water for at least 15 million people along the eastern seaboard.

"People definitely realize there's a connection between clean water and healthy aquatic habitats," Zakutansky says, adding that drawing attention to drinking water inspires support for land conservation by "bringing the issue directly home."

After all, it's one thing to feel sympathy for parched denizens of faraway lands. It's quite another to see your neighbor's crops failing, to paddle your canoe onto a sandbar where water used to be, or to find that your own well has run dry—and to realize that protecting headwaters and watershed lands can help prevent these things from happening again.

Water conservation, once a matter of remembering to turn the tap off while you brushed your teeth, must be broader, more thoughtful, and more coordinated in the 21st century. And the water footprint might just be a step in the right direction.

Water Footprint Calculators
Americans use the most water in the world, according to the Water Footprint Network. Curious about how your own habits measure up? Try one of these calculators.

Water Footprint Network. This is the original—and also the most formal. It's geared toward the metric-savvy, so be ready to estimate the kilograms of food you eat each week.

H2O Conserve. Run by the GRACE Foundation, this site offers a more U.S.-friendly calculator, as well as tons of tips for saving water at home.

National Geographic. Frustratingly vague at times—is my yard small, medium, or large?—this is the most fun to use (and offers full explanations behind the scenes).