What term describes the time water stays in a basin?

The term that describes the time water stays in a basin is "detention time." This concept refers to the duration that water remains in a specific location, such as a reservoir, pond, or any water-holding basin, before it either evaporates, infiltrates into the ground, or moves downstream. Understanding detention time is essential for water resource management, as it affects water quality, sediment transport, and the ecological health of aquatic systems.

While "retention time" might sound similar, it is more commonly used in specific contexts relating to wastewater treatment processes where it refers to the time water remains in a treatment unit to allow for adequate treatment. "Circulation time" typically pertains to the movement of water through a broader system, such as oceans or atmospheres, and does not specifically describe the duration of water stored in a basin. "Flow time" might also relate to the movement of water but lacks the focus on how long water is held in a static state within a basin. Thus, detention time is the precise term that captures the essence of the time water remains in a defined storage area.