Back in 2007, Levi's did a cradle-to-grave assessment of the resources required for its famous 501 denim

and found out something surprising: its jeans were practically made of water. The San Francisco-based

company discovered that over the lifetime of its jeans, from the cotton fields needed to make the fabric to

consumers' tossing their dirty dungarees in the washing machine, each pair used up 3,480 L of water,

which is the equivalent of running a garden hose for 106 minutes.

There wasn't much Levi's could change about cotton farming or consumer hygiene, but company

executives realized they could use ozone processing to reduce the amount of washing needed to soften

jeans before they're sold — i.e., the wash in stonewashed. The result is Levi's Water‹Less jeans, a new

line that hits stores in January. On average, the jeans, which will cost the same as conventional ones,

use 28% less water in the finishing process. Multiply that by the more than 1.5 million pairs of Water‹Less

jeans Levi's expects to sell this spring and the savings add up to approximately 16 million L of water. "It

took a different way of thinking, but the results are kind of amazing," says Carl Chiara, director of special

projects at Levi's.

Fashion may seem low impact — after all, consumers don't use electricity or burn gasoline when they put

on their khakis — but growing cotton and other fibers involves a lot of water and fertilizer, and a great

deal of energy is needed to manufacture, ship and, eventually, wash and maintain the clothes that wind

up in your hamper. Some 25% of the world's pesticides, for example, is used to grow cotton, and on

average, 15% to 20% of the fabric that goes into producing clothing ends up as scraps.

One way to shrink fashion's environmental impact is through efficiency initiatives that reduce the need for

water, pesticides and energy in the manufacture of clothes — just as Levi's has done with its new line.

Using natural dyes rather than harsh chemicals can also cut down on the pollutants from prêt-à-porter.

Some fashion pioneers are trying to push the boundaries of sustainability further by purposefully

designing clothes that leave little to no waste. This involves techniques like creating a scrap-free pattern

that fits together like a puzzle. But the overall look still has to be attractive. "The waste can't be more important than the aesthetics," says Timo Rissanen, an assistant professor of fashion design and

sustainability at New York City's Parsons the New School for Design. "It should still be about designing

beautiful things."

For now, however, zero waste is on the margins of design, and efficiency improvements like Levi's

Water‹Less jeans are barely a drop in the bucket. That's why the most dedicated followers of sustainable

fashion might want to limit the amount of clothing they buy — and make sure those choices last a long

time. "It's easy to confuse needs with wants," says Rissanen. "I do believe in buying less and buying

better." That may be the greenest design of all.