Water Management
Groundwater Dependent Ecosystems
Groundwater is water which is found below the water table in saturated soil and rocks. Water–bearing zones are called aquifers and they can provide significant quantities of water for stock, irrigation, domestic use, towns, mining and other commercial purposes. Importantly, they are also the source of water to groundwater dependent ecosystems.
Groundwater dependent ecosystems (GDE) are a diverse and important component of biological diversity. The term GDE takes into account ecosystems that use groundwater as part of their survival strategies, and so GDEs can potentially include wetlands, vegetation, mound springs, river base flows, cave ecosystems, playa lakes and saline discharges, springs, mangroves, river pools, billabongs and hanging swamps. The groundwater dependence of ecosystems can range from complete reliance to a partial reliance on groundwater, such as might occur during droughts. The degree and nature of dependency of these ecosystems on groundwater will influence the extent to which they are affected by changes to the groundwater system, both in quality and quantity.
Ecological processes in groundwater dependent ecosystems are threatened by the regular extraction of groundwater and changes in land use or management. Species and communities thatrequire permanently wet conditions, particularly in arid, semiarid or seasonally dry conditions are more likely to be groundwater dependent than those tolerant of a regular cycle of wetting and drying. Groundwater pressure and temperature in the Great artesian Basin mound springs ecosystems play an important role in maintaining endemic species.
The National Water Initiative (NWI) recognises the importance of protecting groundwater-dependent ecosystems and calls for the development of better understanding of the relationship between groundwater and important groundwater-dependent ecosystems.
The Department of Water and Energy is undertaking collaborative work with the National Water Commission into how best to identify groundwater dependent ecosystems and assess their condition.
Documents on groundwater contamination and groundwater vulnerability mapping can be found at Groundwater contamination.