But the Colorado River, a lifeblood that sustains 40 million people and four million acres of farmland across seven states in the south-western US and two states in northern Mexico, is an increasingly stressed resource. Decades of over pumping and the worst drought in 1,200 years have severely depleted the waterway and the reservoirs it feeds. Last year, for the first time ever, the US government declared a shortage on the river, triggering widespread restrictions across the region.