1. Consider the water footprint of your diet. Some foods require a lot more water to produce than others. According to WaterFootprint, it takes 140 liters (35 gallons) of water to make just one cup of coffee, 1,000 liters (270 gallons) to make one liter of milk, and 16,000 liters to make one pound of beef. Check out this online water footprint calculator to see how much water some common foods need in order to be produced. The same principles of decreasing the carbon footprint of your diet (eating local, eating organic, and eating less meat) are generally the same principles for decreasing the water footprint.