By Eilene Lyon
“We know surprisingly little about vanished civilizations whose majesty and whose ultimate demise were closely linked to liberties they took with water.” – Marc Reisner, Cadillac Desert: The American West and Its Disappearing Water
It’s no secret that the southwestern United States is a dry place—and getting drier. We’ve entered our third decade of drought and there is no end in sight. The two largest reservoirs, Lake Mead and Lake Powell, stand at 32% and 24% of capacity, respectively. According to the Lake Powell Water Database, inflows to the lake so far this water year (at day 200) are 59% of average. The tracked upstream reservoirs are at 64% of capacity.
Spring runoff might improve those figures, but given that our snowpack in Colorado is roughly 92% of the median for 1991–2020, that’s a mighty big IF (as in “IF it rains sometime soon and in a good quantity”).
The population of the six states making up the region was 61.02 million at the 2020 census. That’s an increase of 12.58 million (+26%) since 2000. Every one of those states grew in population over that 20-year period. As water resources continue to become depleted, how will it change the flow of people into and out of the area?
The current drought seems to be mimicking that of 1271–1300 CE, a time when the Ancestral Puebloan communities of the Four Corners were abandoned, sites such as Mesa Verde, Chaco Canyon, Hovenweep, and Canyon of the Ancients. (We know about ancient droughts, thanks to the brilliance of tree-ring data. Obtaining good core samples is a difficult process, as I discovered during my internship at Mesa Verde NP.)
The changing climate nearly a millennium ago not only made agriculture nearly impossible, but food shortages appear to have led to violent upheaval, causing the survivors to scatter. Our understanding is necessarily theoretical, but the fact of these empty villages stand as testament. (Native tribes do not consider them “ruins.”)
Is this the fate that awaits the denizens of today’s Southwest? Will Phoenix, Las Vegas, and San Diego become ghost towns after a spate of violent altercations and mass death? It doesn’t seem too likely, but who really knows?
What is probable begins with agriculture—the number-one consumer of water. Already, almond groves in California are being ripped from the ground and replaced with less water-intensive crops. That’s just a start. Fields all over these states will be fallowed. Herds of cattle will shrink as grazing lands wither and become desertified—a process that’s been ongoing for over a century.
As agriculture is abandoned, more water will be available for urban areas, but where will all these people get their food? If California continues its trend toward becoming a net importer instead of exporter of food, is that a sustainable scenario? Or will people flee the region in a mass exodus?
I have no answers for all the questions I’ve raised here, but they bear thinking about, and developing plans for the most probable scenarios.
Feature image: Chaco Canyon National Park (E. Lyon 1988)