Groundwater commonly supplies or supplements summer flows with cool, oxygenated water and creates focal areas of groundwater discharge that provide important localized habitats crucial to the survival of certain species or aquatic food webs in warm summer rivers. Unfortunately, groundwater pumping reduces the flow of groundwater to many aquatic and riparian ecosystems over timescales ranging from days to centuries and can even interpret streamflow in severe cases.

Environmental flows describe the quantity, quality, timing and range of variability of water flows and levels required to sustain or restore freshwater and estuarine ecosystems and the functions and services they may provide. Environmental flows are fundamental to the management of water resources as a tool for ecosystem and biodiversity conservation and adaptation to climate change at a country scale.