The American south-west is running out of water. We’ve known this would happen for years | Kim Heacox and Jimmy Bluefeather

Welcome to the worst drought in an estimated 1,200 years

If water is the lifeblood of planet Earth, the American south-west is in big trouble.

John Wesley Powell, the one-armed US army civil war veteran who led the first white expedition down the Colorado River through the Grand Canyon - a daring boat run in 1869 - later became an ethnographer who wrote a prescient 1878 government paper titled: Report on the Lands of the Arid Regions of the United States. In it, he unflinchingly described the scarcity of water, and summarized that much of the American south-west, if it must be settled, should be settled lightly and modestly. Overpopulate it, and it will be unforgiving.