- How much water is needed to produce food and how much do we waste? "Approximately 3.8tn cubic metres of water is used by humans annually with 70% being consumed by the global agriculture sector. The amount of water wasted globally that never reach the consumer is estimated at 550bn cubic metres" http://www.guardian.co.uk/news/datablog/2013/jan/10/how-much-water-food-production-waste 6 comments worldnews