Groundwater dependent ecosystems

Ecosystems that rely on groundwater for some or all of their water requirements are classified as Groundwater Dependent Ecosystems (GDE). Not all GDEs draw on groundwater directly and not all are solely reliant on groundwater. However, in many cases groundwater commonly provides an important and reliable source of water to many ecosystems, and can be the main factor controlling the distribution of ecosystem types. In many cases the groundwater provides baseflow in rivers that ecosystems depend on. The impact of changes in groundwater quantity and quality on GDEs is determined by the degree and nature of their groundwater dependency.

Six types of Groundwater Dependent Ecosystems have been identified in Australia:

• terrestrial vegetation that relies on the availability of shallow groundwater
• wetlands such as paperbark swamp forests and mound springs
• river baseflow systems where groundwater discharge provides a significant baseflow component to the river
• aquifer and cave ecosystems where life exists independent of sunlight
• terrestrial fauna, both native and introduced species, that rely on groundwater as a source of drinking water
• estuarine and near-shore marine systems, such as coastal mangroves, salt marshes and sea-grass beds, which rely on the submarine discharge of groundwater.