The American West has a drinking problem. On farms and in cities, we are guzzling water at an alarming rate.

Scientists say that to live sustainably, we should use no more than 40 percent of the water from the Colorado River Basin. As it is now, we use 76 percent, nearly double the sustainable benchmark.

The water supports the populations of California, Arizona, Nevada, Utah, New Mexico, Colorado and Wyoming, providing for agriculture and cities. With a changing climate and continued population growth, increasing demand for water may make this vital resource increasingly scarce.

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There are some safeguards in place against water scarcity. The reservoir Lakes Mead and Powell can provide approximately five years of average annual stream flow at full capacity for insurance against low rainfall years.

But John Sabo, an associate professor in Arizona State University’s School of Life Sciences, believes that 50 years in the future – rather than five – should be the planning mark for water usage.

“My take on that is we’re already beyond the point where we have enough insurance against the bad years, which is why a year and a half ago we started talking about water rationing before it started raining in December,” says Sabo, who is also director of research development in ASU’s Global Institute of Sustainability.

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After dipping to a record low in 2011, Lake Mead presently sits at below half capacity, and that’s with favorable rainfall and snowpack accumulating in the Rocky Mountains, which feed the Colorado.

Also, to our detriment, there is a culture dedicated to creating an oasis in the Southwest’s arid environment. Most of the West’s water falls in the mountains, where it slowly melts, We collect it and then spread it thin across the deserts. Moving water from wet areas to dry areas makes people feel safe, according to Sabo.

“We have lawns, palm trees and lush green parks because we store water from far away to offset the arid reality of the desert,” he says.

Regardless of how much our lawns guzzle, the largest use of water isn’t in urban areas but in agriculture. Farming uses 77 percent of the water allocated for human use in Arizona, according to the Morrison Institute for Public Policy’s publication “Watering the Sun Corridor.”

For example, Southwestern farms produce approximately 75,000 acres of lettuce annually. As much as 55,000 acres of that is grown in Arizona, according to University of Arizona publications. Of Arizona’s lettuce, 95 percent is grown in the southwestern corner, in Yuma county, which receives an average rainfall of about 3.6 inches.

“People might ask, why are we growing lettuce in Arizona?” questions Sabo. “Well, it’s because it’s warm here in the winter and people want salads in the winter. And if you want a salad in the winter and you don’t want to wait for natural salad season to come around, you’ve got a tradeoff, and that tradeoff is the water footprint.”

The water footprint of produce isn’t often taken into consideration, however.

“There’s this ‘eat local’ movement that has done a great job to educate people about how your decisions at the supermarket relate to your carbon footprint and climate change,” says Sabo. “But there’s nothing like that for water, and I think there needs to be.”

Since most water isn’t used for cities, urban lifestyle changes aren’t going to do much to solve the problem. Shorter showers and eco-friendly appliances aren’t enough to make a significant impact on our massive water use.