Cadillac Desert: The American West and Its Disappearing Water

by Marc Reisner

When it came to irrigation, however, the Hohokam were in a league by themselves. The largest of the canals they dug was fifteen miles long and eleven yards wide from bank to bank; like the other main canals, it had a perfectly calibrated drop of 2.5 meters per mile, enough to sustain a flow rate that would flush out most of the unwanted silt. There were dozens of miles of laterals and ditches, implying irrigation of many thousands of acres of land. Because of the dry climate and the provenance of the irrigated land, the Hohokam should have enjoyed good health; they made superior weapons; they were more populous than any culture around. Why then should they disappear? It is hard to imagine a civilization covering thousands of square miles and comprising hundreds of thousands of people just vanishing, but according to Emil Haury, an archaeologist who became fascinated by their demise, they apparently did. “We are almost totally ignorant of Hohokam archaeology . . . after 1400,” writes Haury in Snaketown, an archaeological record of the impressive Hohokam artifacts he and his colleagues unearthed. The relatively few Pima Indians whom whites found living in central Arizona in the 1800s were presumably descended from the Hohokam—which in Pima language, means “those who have gone”—but they offered no explanation as to what happened to them. Drought remains a possibility—perhaps a twenty-year drought the likes of which they had never seen—but an equally plausible explanation is t...