Centennial Wash (Maricopa County)

Centennial Wash is an ephemeral stream located in Maricopa County, Arizona. It is a tributary of the Gila River. The wash is characterized by its intermittent flow, typically only containing water following significant rainfall events. The watershed contributing to Centennial Wash is primarily undeveloped desert land, though increasing urbanization in the surrounding areas is impacting the hydrology of the wash.

The wash serves as a drainage channel for stormwater runoff and plays a role in groundwater recharge. Due to its ephemeral nature, vegetation along the wash is typically drought-tolerant and adapted to infrequent flooding. The Centennial Wash area provides habitat for a variety of desert wildlife. Concerns exist about potential flooding hazards associated with the wash during periods of heavy precipitation, particularly as development encroaches upon the floodplain. Studies and mitigation efforts have been undertaken to manage flood risks and protect property in the vicinity of Centennial Wash.