Six major types of groundwater dependent ecosystems have been identified:
- terrestrial vegetation - vegetation communities and dependent fauna that have seasonal or episodic dependence on groundwater
- river base flow systems - aquatic and riparian ecosystems that exist in or adjacent to streams that are fed by groundwater base flow
- aquifer and cave ecosystems - aquatic ecosystems that occupy caves or aquifers
- wetlands - aquatic communities and fringing vegetation dependent on groundwater fed lakes and wetlands
- terrestrial fauna - native animals that directly use groundwater rather than rely on it for habitat
- estuarine and near-shore marine ecosystems - coastal, estuarine and near shore marine plant and animal communities whose ecological function has some dependence on discharge of groundwater
The response of groundwater dependent ecosystems to change in the key attributes (level or pressure, discharge flux, quality of water) is variable. There may be a threshold response in some cases, whereby an ecosystem collapses completely if a certain attribute value is exceeded. For example, mound spring communities supported by groundwater could cease to exist if pressure in the aquifer fell to the point where there was no further surface discharge. In other cases a more gradual change in the health, composition and/or ecological function of communities may occur as, for example, with increasing groundwater salinity or contaminant concentration.
Ecosystems dependent on groundwater face a broad range of direct and indirect threats. The main pressures are: water resource development, agricultural land use, acid sulphate soils, urban and commercial development, mining and plantation forestry.
There is wide variability between the groundwater planning processes used in each of the Australian states and territories. In Queensland and Victoria many groundwater management units are over-allocated, despite the current lack of explicit provision of water for environmental purposes.
|Threat to ecosystem||Vulnerability||Risk||Value||Importance|
|Ecosystem||Process||Groundwater attribute||Impact if threat realised||Likelihood of threat being realised||Conservation value of ecosystem||Risk x Vulnerability x value|
|Entirely dependent on groundwater|
|Mound spring ecosystems||Water resource||Pressure||High||High||High||High|
|Karstic groundwater ecosystems||Water resource, agriculture, mining||Level, quality||High||High||High||High|
|Permanent lakes and wetlands of Swan Coastal Plain||Urban & commercial, water resources||Level, quality||High||High||Moderate||High|
|Pilbara spring ecosystems||Mining, water resource, agriculture||Level, quality||High||Moderate||High||High|
|Inland mangrove near 80 Mile Beach in Western Australia||No immediate threat||Level||High||Low||High||High|
|Arid zone groundwater calcrete ecosystems||Water resource, mining||Level, quality||High||Moderate||High||High|
|Riverine aquifer ecosystems||Water resource, agriculture, urban & commercial development||Level, quality||High||High||Moderate||High|
|Marine tide influenced cave (or anchialine) ecosystems||Water resource, mining||Level, quality||High||Moderate||High||High|
|Highly dependent on groundwater|
|Pilbara river pool ecosystems||Water resource, mining, agriculture||Level, quality||High||Moderate||Moderate||High|
|Near shore stromatolites of coastal Western Australia||Urban & commercial, water resource||Level, quality||High||Moderate||High||High|
|Groundwater dependent wetlands of basalt plains of Western Victoria||Water resource, agriculture, forestry||Level, quality||Moderate||High||Moderate||High|
|Damplands of Swan Coastal Plain||Water resource, urban & commercial||Level, quality||High||High||Moderate||High|
|Mesophyll palm vine forests of tropical north Australia||Water resource||Level, flux||High||Low||Moderate||Moderate|
|Solution hollow swamp communities of Eyre and Yorke Peninsulas||Agriculture||Level, quality||High||Low||Moderate||Moderate|
|Permanent water hole ecosystems of rivers and lakes of Central Australian lowlands and South Australian ranges||Water resource, agriculture||Level, quality||High||Low||Moderate||Moderate|
|Melaleuca stands in upper south-east of South Australia||Agriculture||Level, quality||High||Low||Moderate||Moderate|
|Paperbark swamp forests and woodlands of tropical northern Australia||Water resource||Level||Moderate||Moderate||Moderate||Moderate|
|Base flow dependent aquatic ecosystems of uplands of south-eastern Australia||Water resource, agriculture||Level, flux, quality||Moderate||Moderate||Moderate||Moderate|
|Permanent coastal lake, dune and beachridge plain ecosystems of coastal NSW and coastal sand islands of NSW and Qld.||Urban & commercial, water resource, acid sulphate soils||Level, quality||High||High||Moderate||High|
|Phragmites and Typha communities of permanently flooded swamps and lakes of inland areas of the uplands of south-eastern Australia||Water resource, agriculture||Level, quality||High||High||Moderate||High|
|Permanent base flow dependent swamps and river pools of Kangaroo Island||Water resource, agriculture||Level, quality, Flux||Moderate||High||Moderate||High|
|Riparian swampland communities of Mount Lofty Ranges||Water resource, agriculture||Level, quality||Moderate||High||Moderate||High|
|Swan Coastal Plain damplands and sumplands with paperbark and Banksia woodlands||Water resources, urban & commercial||Level, quality||High||High||Moderate||High|
|Coastal swamp scrub sedgeland communities in the near-coastal dune systems of the Upper South East of South Australia||Agriculture||Level||High||Moderate||Moderate||High|
|Base flow dependent ecosystems in south-western Western Australia||Water resources, agriculture, forestry||Level, quality||Moderate||Moderate||Moderate||Moderate|
|Lake and riparian sedgelands, swamp heaths and bog communities in Tasmania||Agriculture, water resources||Level||Moderate||Low||Moderate||Moderate|
|Groundwater dependent seasonally-permanently waterlogged swamp heathlands, sedgelands, and Phragmites grasslands in Tasmania, where waterlogging is dependent on groundwater levels||Agriculture, water resources, forestry, urban & commercial||Level, quality||Moderate||Moderate||Moderate||Moderate|
|River pool and billabong herblands of floodplains in tropical northern Australia||Mining, agriculture||Level, quality||Moderate||Low||Moderate||Moderate|
|Base flow dependent herbland ecosystems of uplands and plateaux of northern Australia||Mining, agriculture||Level, flux||Moderate||Low||Moderate||Moderate|
|Lake ecosystems of major river systems of north-eastern Australia||Agriculture||Level, flux||Moderate||Low||Moderate||Moderate|
|Volcanic crater lakes and swamps of Cape York Peninsula||Agriculture, water resource||Level, quality||Moderate||Low||High||Moderate|
|Permanent glacial lakes supporting wet tussock and Carex grasslands and Sphagnum swamps in the south-eastern uplands||No immediate threat||Level||High||Low||Moderate||Moderate|
|Swamp heaths and sclerophyll forests of the Hawkesbury Sandstones and inland floodplains of the uplands of south-eastern Australia||Water resource, agriculture, urban & commercial||Level||Moderate||Moderate||Moderate||Moderate|
|Eleocharis and Baumea sedgelands in lagoons of the inland rivers of the south-eastern Australia||Water resource, agriculture||Level||Moderate||Moderate||Moderate||Moderate|
|Alpine bogs in the highlands of NSW and Victoria||No immediate threat||Level||Moderate||Low||Moderate||Moderate|
|Ecosystems fringing the Gippsland Lakes in eastern Victoria||Agriculture, urban & commercial||Level, quality||Moderate||Moderate||Moderate||Moderate|
|River plain grasslands on the floodplains of the North Australian Plateau||Mining, agriculture||Level, flux||Low||Low||Low||Low|
|Tropical sclerophyll forests and woodlands on the North Australian Plateau||Water resource, agriculture||Level||Low||Low||Low||Low|
|Ecosystems with opportunistic groundwater dependence|
|Ecosystems of the Coorong||Agriculture, water resources||Level, quality||Moderate||High||High||High|
|Ecosystems of permanent lakes and swamps at termini of inland rivers in the Central Lowlands and South Australian Ranges||Agriculture, water resource||Level||High||Moderate||Moderate||High|
|Major ocean embayments such as Port Phillip Bay||Agriculture, urban & commercial, acid sulphate soils||Flux, level, quality||Moderate||High||Moderate||High|
|Intermittent floodplain lakes of the Central Lowlands||Agriculture, water resource||Level, quality||Moderate||Moderate||Moderate||Moderate|
|Swamp sclerophyll forests on the coastal floodplains of the uplands of south-eastern Australia, and of the Lander-Barkly Tablelands||Agriculture||Level||Moderate||Moderate||Moderate||Moderate|
|Jarrah forest and Banksia woodlands of south-western WA||Agriculture||Level||Moderate||Moderate||Low||Moderate|
|Lignum shrublands on inland river systems||Agriculture, water resource||Level||Moderate||Moderate||Low||Moderate|
|Coastal mangrove and salt marsh ecosystems||Agriculture, urban & commercial, acid sulphate soils||Level, quality||Moderate||High||Low||Moderate|
Source: Sinclair Knight Merz Pty Ltd 2001, Environmental Water Requirements of Groundwater Dependent Ecosystems, Department of the Environment and Heritage, viewed 16 Nov 2005, http://www.deh.gov.au/water/
rivers/nrhp/groundwater/chapter2.html, Table 2.1
There are 334 mound springs in the Great Artesian Basin, mostly in South Australia or Queensland. The ecosystems associated with these mound springs are totally dependent on artesian pressure. Significant pressure recovery has occurred in the Flinders Zone, but only moderate to minor recovery has occurred in other spring zones. The effects of pressure recovery on overall spring health is variable and may take many years to be observable.
In response to declining pressures and water levels in the Great Artesian Basin there has been the capping of many bores, the piping of drainage canals, and the restoration of some spring wetlands.
Source: Hassall and Associates Pty Ltd 2003, Review of the Great Artesian Basin sustainability initiative, Department of Agriculture, Fisheries and Forestry, Canberra, viewed 4 Oct 2005, http://www.affa.gov.au/content/publications.cfm?
Number of artesian bores controlled (reconditioned, plugged, replaced, piped) under the Great Artesian Basin Sustainability Initiative
Source: Hassall and Associates Pty Ltd 2003, Review of the Great Artesian Basin sustainability initiative, Department of Agriculture, Fisheries and Forestry, Canberra, viewed 4 Oct 2005, http://www.affa.gov.au/content/publications.cfm?ObjectID=07F7F8F9-DD6A-4E87-93BC79E638BBCDDB.
If groundwater is to be managed according to the principle of ecological sustainable development then resources need to be managed to conserve biological diversity. This can only be if some allocation of groundwater is provided to meet the needs of dependent ecosystems.
Where surface water and groundwater interact, integrated management would be appropriate.
Limited data are available on management of groundwater dependant ecosystems.
The existence of groundwater management plans that consider groundwater dependent ecosystems is indicative of the extent to which this issue is receiving consideration in water management.
Other indicators for this issue:
- IW-05 Average annual groundwater depth
- IW-06 Average annual groundwater pressure
- IW-08 Groundwater used for irrigation
- IW-09 Groundwater used for urban/industrial
- IW-43 Implementation of National Water Initiative
- IW-44 Sustainable yield determination
- IW-46 Implementation of COAG principles
- IW-48 Ramsar wetlands with implemented management plans
Groundwater dependent ecosystems represent a small, but diverse and important component of Australia's biological diversity. The existence of groundwater management plans that consider groundwater dependent ecosystems is indicative of the extent to which this biodiversity issue is receiving consideration in water policy and management.
Other indicators for this issue:
- IW-36 Willow removal
- IW-48 Ramsar wetlands with implemented management plans
- BD-03 Summary of measures being implemented to respond to threats to biodiversity from invasive species
Groundwater management plans that consider groundwater dependent ecosystems indicate a focus on habitat management.
Other indicators for this issue:
- Great Artesian Basin Consultative Council - Annual Report 2001-2002
- Review of the Great Artesian Basin Sustainability Initiative (Hassall and Associates Pty Ltd 2003)
- Biograze - Waterpoints and Wildlife
- Environmental Water Requirements of Groundwater Dependent Ecosystems (Sinclair Knight Merz Pty Ltd 2001)
Links to another web site
Links to data in the DRS
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