There is always "water footprint" embedded in food or other products. The amount of fresh water used is even greater than we could imagine.
For example, the water footprint for a 16oz steak is about 7000L:
1. Around 280L of water for cow to drink
2. Around 6500L of water used to produce grains and roughages
3. Around 210L of water for servicing
Meanwhile, the water footprint for a cotton T-shirt is about 2500L:
1. Around 2200L of water for growth of cotton (from precipitation and irrigation)
2. Around 300L of water for dyeing
High water footprint causes higher impact on the environment. In Central Asia, for example, excessive abstractions of water for cotton irrigation have resulted in the near-disappearance of the Aral Sea.
Understanding the concept of water footprint not only let us know the impact of our daily life to water resources, but also let us be aware of water crisis that every place in the world cannot escape from.
Source: Water Footprint Network