The Hohokam Cultural Sequence (Irrigation and Foraging), Sonoran Desert, greater Phoenix basin, Arizona, USA

Resource System
Lower Sonoran watershed and associated terrestrial biodiversity
Resource Units
Freshwater, desert plants and animals

The Hohokam is a Native American cilivilization that emerged and occupied the present day Phoenix Basin area and its outer bounds for a thousand years. The archeological records indicate that the Hohokam society evolved into a complex irrigation society and reached its peak in levels of population, social institutions, and irrigation infrastructure by the 11th century.

Perplexingly though, the Hohokam society subsequently declined and collapsed by the mid 14th century. As they declined, the Hohokam abandoned their irrigation-related infrastructure and social institutions. The motivation behind their evolution into a complex irrigation society is not hard to deduce – irrigation and associated institutional changes tend to make their subsistence robust to some familiar disturbances. This is so because such 'buffering' infrastructure can reduce the impact of climate variability (e.g., frequent local droughts) on the food production level. The reason why they collapsed, however, is not clearly known.

Based on the archeological records, this case explores the likely social and ecological interactions that took place and how those interactions impacted the robustness of the Hohokam society. This can shed some light on why the Hohokam collapsed.