“To walk down a gravel road just south of the border town of San Luis Rio Colorado and watch what remains of the Colorado pass through rusted culverts, bringing not fertility but toxicity to the land, is to ask what on earth become of this stream so revered in the American imagination, and yet now so despoiled that it today reaches the ocean a river only in name.”

If you’ve ever been in North America during the winter and eaten lettuce, you’ve drunk from the Colorado. The Yuma region, which gets 4 inches of rain a year, grows 95% of North America’s winter lettuce, watered almost exclusively by the Colorado. Without the river, America would be forced to largely abandon southern California and Arizona, and much of Colorado, New Mexico, Nevada, Utah, and Wyoming; upwards of 25 million people forced to relocate, not to mention eat less lettuce. As it withers, the animals, plants, and natural beauty that rely on it wither too.

Wade Davis mourns its treatment. Wade Davis, for those who don’t know him, is a possessor of one of the coolest jobs I’m familiar with, being one of the seven permanent Explorers-in-Residence at National Geographic, and is the guy who explored how zombies were created in Haiti.

Framed by his own rafting journey down the Grand Canyon, he weaves together stories of the native people around the river, both the Anasazi, the Ancient Ones, whose ruins cover the area, as well as extant groups; the stories of the first Europeans to explore the river; its geological and natural history; and its exploitation through dam construction and water diversions.

Americans may find his lament particularly powerful, but beyond enjoyment of his beautiful writing, I also took away a number of broader lessons. Water is a resource we tend to squander, and we have not yet begun to bear the costs of such behaviour, at least in the Western world. We also tend to lionize dams as a solution to global warming, and as such River Notes is a useful reminder that they too have costs, like all sources of energy. Most of all, though, he ends on an optimistic call to action: to maintain the Colorado ecosystem may take as little as 1% of the total flow, and if it were not for “cows eating alfalfa in a landscape where neither really belongs,” he points out, the entire crisis could be averted. It takes, after all, over 1800 litres of water to raise a pound of beef.

Disclosure: I read River Notes as a free advance reader copy – it is released on Saturday. You can get it here (or in the UK or Canada).