You might be surprised by how much water it takes to grow and make our food. The food we eat makes up more than 2/3 of our total water footprint, mostly because of all the "virtual water" needed to produce that food. It seems pretty obvious when you really think about it; crops can’t grow without water. In the US, agriculture is responsible for 80 percent of all water consumed (water that is evaporated or otherwise removed from the watershed).
Let’s take a look at a typical lunch. A loaf of bread requires about 240 gallons of water, and a pound of cheese takes about 382 gallons. So a simple cheese sandwich takes about 56 gallons of water. Throw in a small bag of potato chips at 12 gallons and you just ate about 68 gallons of water. Add some turkey and it jumps to 160 gallons! Thirsty? Rinse your sandwich down with an ice cold soda and you can add an extra 46 gallons of water onto your tab.
The sheer amount of water used to make the food we eat every day can be mind-boggling.
Let’s take a closer look at meat. Pound for pound, it has a much higher water footprint than vegetables, grains or beans. For instance, a single pound of beef takes, on average, 1,800 gallons of water. That huge water footprint is primarily due to the tremendous amount of water needed to grow the grass, forage and feed that a beef steer eats over its lifetime, plus water for drinking, cleaning and processing.
In the US, at least 80 percent of beef cattle are "conventionally" raised. This means they eat grass in pasture, typically for 12 to 14 months, then they go to a feedlot for three to six months, where they eat feed made from corn and soy, because a grain-heavy diet speeds up the cattle’s growth. It takes about 147 gallons of water to produce one pound of corn, and a beef steer or heifer can eat 1,000 pounds or more of feed over a few months. All that grain and water really adds up!
It also adds up for the average American who eats about 167 pounds of meat a year – three times the global average! By eating more vegetables, grains and beans and eating less meat, you can save water.
Another important part of using water and other resources productively is to think about where our food comes from and how it is made. California produces more food than any other US state, supplying a large part of the country's milk, beef, produce and nuts. It is also one of the nation's driest states and is in the midst of an historic drought. As a result, California's agricultural sector puts enormous pressure on the water supplies of the entire southwest, often shipping those limited water resources overseas as food exports. Likewise, when we buy food that's been shipped from other states and countries, we're tapping into distant water supplies, too.
Transporting food over long distances also requires large quantities of fuel that pollute the air, contribute to climate change and use a great volume of water. That's because it takes water to produce gasoline and other transportation fuels. In fact, it takes about 3/4 gallon of water to produce the gasoline needed to drive 1 mile.
Diets that are made up of highly processed foods (like candy, chips and ready-made meals) also take a lot of water. Take, for example, the potato chip (as compared to a whole potato). After growing the potatoes – which takes the biggest portion of water – potato chip-processing takes additional water to clean potatoes and machinery, produce cooking oil for deep frying, produce the fuel for delivery, produce packaging, and so forth. The water use accumulates above and beyond what it would take to produce and eat a whole potato.
In short, the more meat, dairy and processed foods we eat, the more water we consume. The next time you're thinking about what's for lunch, you might also want to appreciate how much water it took to make that meal.