It is important to maintain the quantity and quality of water in the aquifer, that is, the integrity (resilience) of the aquifer, so that it has the ability to yield water now and in the future. Risks to aquifer integrity can arise if abstraction alters the aquifer’s water quality (e.g. through saline water intrusion). Risks to aquifer integrity can also occur through subsidence, where the removal of water from the aquifer leads to its compaction. The level of risk to groundwater-dependent ecosystems from abstraction depends on how much they rely on groundwater, their sensitivity to changes in the quantity and quality of groundwater and their significance as ecosystems.