A GREAT ARIDNESS

New Mexico writer and conservationist deBuys (The Walk, 2007, etc.) offers a more-in-sadness-than-anger history of the land he loves and those who have exploited it, studied it and tried to fix it.

An immense arid area that includes a chunk of Mexico, it has usually supported farming and ranching. After 800 CE, a rich Native American culture flourished, ultimately building great cliff houses and roads before abandoning them after 1250 in the face of increasing drought. White settlers streamed in after 1800; 100 years ago, experts began warning that the area’s water resources could not support its population. There followed massive dam and canal construction since the 1930s, which tapped the Colorado River, allocating water to six states and Mexico. Most readers will be unsurprised to learn that the original allocations were too generous and that dwindling flow will produce a crisis within decades. Increasing dryness has also produced the Southwest’s worst forest fires in history, and increasing warmth has stimulated bark beetles, which have killed huge swaths of woodland. DeBuys delivers thoughtful portraits of efforts to ameliorate conditions, but some require controlling the region’s burgeoning growth, a strategy with little political support. No Pollyanna, he admits that the list of societies willing to accept difficult medicine in order to spare their descendants worse pain is extremely short.

Although they may miss the traditional upbeat ending, readers will appreciate this intelligent account of water politics, forest ecology and urban planning in a region seriously stressed even before global warming arrived to make matters worse.