Flood-damaged canals and human response, A.D. 1000–1400, Phoenix, Arizona, USA

Abstract

The scale of prehistoric canal construction in the North American Southwest peaked in A.D. 450–1450, during what has been named the Hohokam Millennium. Explanations for the eventual Hohokam “collapse” remain elusive. Environmental disturbances, such as floods, that were once manageable may have become unmanageable. Recent archaeological excavations of Hohokam canals in Phoenix identified stratigraphic evidence for three destructive floods that date to A.D. 1000–1400 within two large main canals in System 2, Hagenstad and Woodbury’s North. Woodbury’s North Canal was flood-damaged and abandoned sometime after A.D. 1300. Thereafter, no main canals of similar size were constructed to supply villages within System 2 and the area was depopulated. Our investigation provides the first stratigraphic evidence for a destructive flood during the late Classic period in the lower Salt River Valley and is compatible with the hypothesis of diminished resilience to environmental disturbance at the end of the Hohokam Millennium.