Hyporheic zone

The hyporheic zone is the region of sediment and porous space beneath and alongside a stream bed, where there is mixing of shallow groundwater and surface water. The flow dynamics and behavior in this zone (termed hyporheic flow or underflow) is recognized to be important for surface water/groundwater interactions, as well as fish spawning, among other processes. As an innovative urban water management practice, the hyporheic zone can be designed by engineers and actively managed for improvements in both water quality and riparian habitat.

The assemblages of organisms that inhabits this zone are called hyporheos.

The term hyporheic was originally coined by Traian Orghidan in 1959 by combining two Greek words: hypo (below) and rheos (flow).