Of the 882 ecological assets in the asset list, 772 were deemed to be water dependent for the purposes of the BA. The water-dependent assets register contains 468 assets in the ‘Vegetation’ subgroup, 12 in the ‘Groundwater feature’ subgroup and 292 in the ‘Surface water feature’ subgroup. A more detailed summary of the distribution of assets according to asset class in the asset list is presented in Table 7.
Table 7 Summary of ecological assets within the Central West subregion
|
Subgroup |
Asset class |
Not in water-dependent asset register |
In water-dependent asset register |
Total assets (asset list) |
|---|---|---|---|---|
|
Groundwater feature (subsurface) |
Aquifer, geological feature, alluvium or stratum |
0 |
12 |
12 |
|
Groundwater total |
0 |
12 |
12 |
|
|
Surface water feature |
Floodplain |
0 |
6 |
6 |
|
Lake, reservoir, lagoon or estuary |
0 |
4 |
4 |
|
|
Marsh, sedgeland, bog, spring or soak |
0 |
27 |
27 |
|
|
River or stream reach, tributary, anabranch or bend |
0 |
42 |
42 |
|
|
Wetland, wetland complex or swamp |
0 |
213 |
213 |
|
|
Surface water total |
0 |
292 |
292 |
|
|
Vegetation |
Groundwater-dependent ecosystem |
86 |
259 |
345 |
|
Habitat (potential species distribution) |
24 |
209 |
233 |
|
|
Vegetation total |
110 |
468 |
578 |
|
|
Total |
|
110 |
772 |
882 |
Data: Bioregional Assessment Programme (Dataset 1)
Groundwater features
All 12 assets listed in the ‘Groundwater feature (subsurface)’ subgroup were ‘assumed to be water dependent’ and included in the water-dependent asset register for further consideration during the Assessment (Table 7). The majority of these groundwater features were aquifers identified in the Water Asset Information Tool (WAIT) database for the Central West (Australian Government Department of the Environment, Dataset 2). One asset, the Cadna-owie – Hooray Equivalent (Pilliga Sandstone), is identified as a Great Artesian Basin recharge area (Geoscience Australia, Dataset 9).
Surface water features
All 292 of the assets listed in the ‘Surface water feature’ subgroup were assumed to be water dependent (Table 7). There are many assets in the ’Wetland, wetland complex and swamp’ class distributed throughout the subregion, often covering only small areas in the eastern part, with more extensive coverage towards the north-west as the drainage nears the Barwon River and floodplains become prevalent. The Macquarie Marshes area, situated along the north-western flow of the Macquarie River is listed in several databases and has been classified in multiple ways. These include ‘Marsh, sedgeland, bog, spring or soak’, and as ‘Floodplain’ and ‘Wetland, wetland complex or swamp’ (Figure 4).
Figure 4 Surface water features in Central West subregion
Some assets are represented multiple times within the asset register. For example, the Macquarie Marshes, shown as ‘Marsh, sedgeland, bog, spring or soak’, are also classified as ‘Floodplain’ and ‘Wetland, wetland complex or swamp’.
Data: Bioregional Assessment Programme (Dataset 1); Australian Government Department of the Environment (Dataset 2, Dataset 5, Dataset 6, Dataset 8); NSW Department of Environment, Climate Change and Water (DECCW) (Dataset 3); Office of Environment and Heritage (OEH) NSW (Dataset 4); Murray-Darling Basin Authority (Dataset 7)
Vegetation
Assets listed in the ‘Vegetation’ subgroup consist of two classes: ‘Groundwater‑dependent ecosystems’ or ‘Habitat (potential species distribution)’.
Groundwater-dependent ecosystems
All 345 assets identified as ‘Groundwater-dependent ecosystems’ were sourced from the National atlas of groundwater dependent ecosystems (GDE Atlas; Bureau of Meteorology, Dataset 10). A breakdown of the ecological assets identified as being dependent on the surface water expression of groundwater and the subsurface water expression of groundwater is given in Table 8. Figure 5 and Figure 6 show their spatial distribution, respectively. Approximately 25% of the assets were excluded from the water-dependent asset register because they were deemed to have a low likelihood of dependence on either surface or subsurface expression of groundwater (Table 8).
Table 8 Breakdown of groundwater-dependent assets in the ‘Vegetation’ subgroup for the Central West subregion
|
Subgroup |
Asset class |
Groundwater source |
Not in water-dependent asset register |
In water-dependent asset register |
|---|---|---|---|---|
|
Vegetation |
Groundwater-dependent ecosystem |
Dependent on surface expression of groundwater |
15 |
109 |
|
Dependent on subsurface expression of groundwater |
71 |
150 |
||
|
Total |
86 |
259 |
Data: Bioregional Assessment Programme (Dataset 1)
Data: Bioregional Assessment Programme (Dataset 1); Bureau of Meteorology (Dataset 10)
Figure 6 Groundwater-dependent ecosystems that rely on the subsurface expression of groundwater
Data: Bioregional Assessment Programme (Dataset 1); Bureau of Meteorology (Dataset 10)
Habitat (potential species distribution)
Out of a total of 235 assets, 209 assets within the ‘Habitat (potential species distribution)’ asset class were considered to be water dependent (Table 7).
All assets from the Collaborative Australian Protected Area Database (CAPAD; Australian Government Department of the Environment, Dataset 12) and the Important Bird Areas database (Birds Australia, Dataset 13) were deemed to be water dependent. Of the NSW state government assets, all assets derived from the Travelling Stock Route Conservation Values (NSW Department of Environment, Climate Change and Water (DECCW), Dataset 14), Native Vegetation Management areas (NSW Department of Environment, Climate Change and Water (DECCW), Dataset 15) and NSW Climate Change Corridors (Office of Environment and Heritage (OEH) NSW, Dataset 17) were deemed water dependent.
The remaining assets were either categorised as ‘Threatened ecological communities’, or ‘Habitat of threatened ecological species’.
Threatened ecological communities
Six communities listed under the EPBC Act occur in the Central West subregion, and all were assumed to be water dependent (Table 9). The ‘White Box-Yellow Box-Blakely's Red Gum Grassy Woodland and Derived Native Grassland’ communities are located in the east of the subregion and together with the ‘Weeping Myall Woodlands’ located more in the west cover large extents in the Central West subregion. ‘Coolibah - Black Box Woodlands of the Darling Riverine Plains and the Brigalow Belt South Bioregions’ are more prevalent in the north-west (Figure 7). The GAB spring-dependent species occur in a small area in the north-west of the subregion. ‘Natural grasslands on basalt and fine-textured alluvial plains of northern New South Wales and southern Queensland’ only occur in a small area towards the north-east of the subregion, while ‘Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia’ are located mainly in the east throughout the subregion (Figure 7).
Table 9 Water-dependent threatened ecological communities in the Central West subregion listed under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999
|
Name |
Comments |
|---|---|
|
Coolibah - Black Box Woodlands of the Darling Riverine Plains and the Brigalow Belt South Bioregions |
Likely to exhibit both surface water and groundwater dependence |
|
Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia |
Box woodlands may exhibit groundwater dependence over areas of shallow groundwater |
|
Natural grasslands on basalt and fine-textured alluvial plains of northern New South Wales and southern Queensland |
On alluvial plains may exhibit surface water dependence |
|
The community of native species dependent on natural discharge of groundwater from the Great Artesian Basin |
Groundwater dependent |
|
Likely to be surface water dependent due to floodplain habitat |
|
|
White Box-Yellow Box-Blakely's Red Gum Grassy Woodland and Derived Native Grassland |
Box woodlands may be groundwater dependent over areas of shallow groundwater |
Data: Bioregional Assessment Programme (Dataset 1); Australian Government Department of the Environment (Dataset 11)
Data: Bioregional Assessment Programme (Dataset 1); Australian Government Department of the Environment (Dataset 11)
Names in the legend have been shortened. Full names can be found in Table 9
Habitat of threatened ecological species
Fifty threatened species listed under the EPBC Act were identified in the Central West subregion (Bioregional Assessment Programme, Dataset 18). Of these, 24 were excluded from the water-dependent asset register because a demonstrated surface water or groundwater dependency of the habitat could not be established (Table 7). The excluded assets include 15 plant species, 5 bird species, 1 marsupial, 1 reptile and 2 rodents. Species included in the water-dependent asset register are listed in Table 10.
Table 10 Water-dependent threatened species in the Central West subregion listed under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999
Although examples of individual species are listed, bioregional assessments consider the potential impacts to the habitat of the species not the individual species per se.
|
Functional group |
Scientific namea |
Common namea |
Dependence on surface water |
Dependence on groundwater |
Comment |
|---|---|---|---|---|---|
|
Plants |
Philotheca ericifolia |
NA |
Likely |
Likely |
Occurs in damp sites creek beds and gullies |
|
Swainsona murrayana |
Slender Darling-Pea |
Likely |
Possible |
Associated with black box communities |
|
|
Lepidium aschersonii |
Spiny Pepper-Cress |
Likely |
Possible |
Occurs periodically in wet sites such as gilgai and margins of freshwater and saline marshes and lakes |
|
|
Eleocharis obicis |
A spike Rush |
Likely |
Unlikely |
Species grow in ephemerally wet locations |
|
|
Maireana cheelii |
Chariot Wheels |
Likely |
Unlikely |
Often associated with floodplains or low lying areas that become water logged |
|
|
Cynanchum elegans |
White-Flowered Wax Plant |
Likely |
Possible |
Habitat may overlap with other water dependent habitats |
|
|
Birds |
Botaurus poiciloptilus |
Australasian Bittern |
Likely |
Likely |
Prefers permanent shallow wetlands tall dense vegetation |
|
Rostratula australis |
Australian Painted Snipe |
Likely |
Possible |
Inhabits shallow temporary and permanent wetlands |
|
|
Ardea ibis |
Cattle Egret |
Likely |
Possible |
Occurs in temperate grasslands woodland and wetlands |
|
|
Anthochaera Phrygia |
Regent Honeyeater |
Likely |
Possible |
Prefers fertile sites along creek flats, riparian vegetation |
|
|
Ardea alba |
Great Egret |
Likely |
Possible |
Prefers wide range of habitats-inland and coastal, freshwater and saline, permanent and ephemeral, open and vegetated, large and small, natural and artificial wetlands |
|
|
Haliaeetus leucogaster |
White-Bellied Sea-Eagle |
Likely |
Possible |
Coastal habitats and terrestrial wetlands |
|
|
Himantopus himantopus |
Black-Winged Stilt |
Likely |
Unlikely |
It inhabits most wetlands but does prefer shallow open freshwater areas |
|
|
Calidris ferruginea |
Curlew Sandpiper |
Likely |
Unlikely |
Recorded inland, including around ephemeral and permanent lakes, dams, waterholes and bore drains, usually with bare edges of mud or sand |
|
|
Apus pacificus |
Fork-tailed Swift |
Likely |
Possible |
They mostly occur over dry or open habitats, including riparian woodland and tea-tree swamps, low scrub, heathland or saltmarsh. |
|
|
Gallinago hardwickii |
Latham’s Snipe |
Likely |
Likely |
Occurs in permanent and ephemeral wetlands |
|
|
Tringa stagnatilis |
Marsh Sandpiper |
Likely |
Likely |
Lives in permanent or ephemeral wetlands of varying salinity, including swamps, lagoons, billabongs, saltpans, saltmarshes, estuaries, pools on inundated floodplains, and intertidal mudflats |
|
|
Pandion haliaetus |
Osprey |
Likely |
Likely |
Occurs in littoral and coastal habitats and terrestrial wetlands. Occasionally travel inland along major rivers. They require extensive areas of open fresh, brackish or saline water for foraging |
|
|
Recurvirostra novaehollandiae |
Red-Necked Avocet |
Likely |
Possible |
Freshwater and saltwater wetlands, estuaries, tidal mudflats |
|
|
Calidris ruficollis |
Red-Necked Stint |
Likely |
Likely |
May be seen in sewage farms, saltmarsh, shallow wetlands including lakes, swamps, riverbanks, waterholes, bore drains, dams, soaks and pools in saltflats, flooded paddocks or damp grasslands |
|
|
Calidris acuminate |
Sharp-Tailed Sandpiper |
Likely |
Likely |
In Australasia, the Sharp-tailed Sandpiper prefers muddy edges of shallow fresh or brackish wetlands, with inundated or emergent sedges, grass, saltmarsh or other low vegetation |
|
|
Philomachus pugnax |
Ruff |
Likely |
Unlikely |
Found in terrestrial wetlands including swamps lakes pool, swampy field and floodplains |
|
|
Myiagra cyanoleuca |
Satin Flycatcher |
Likely |
Unlikely |
Mainly inhabit eucalypt forests often near wetlands or water courses |
|
|
Numenius minutus |
Little Curlew |
Likely |
Unlikely |
Most often found feeding in short, dry grassland and sedgeland, including dry floodplains and blacksoil plains, which have scattered, shallow freshwater pools or areas seasonally inundated |
|
|
Mammals |
Phascolarctos cinereus |
Koala |
Likely |
Possible |
May occur in riparian forests or GDE woodland |
|
Dasyurus maculatus maculatus |
Spot-Tailed Quoll |
Likely |
Likely |
Habitat includes inland riparian and river red gum forests |
Data: Bioregional Assessment Programme (Dataset 1)
aPunctuation and typography appear as used in the asset list.
NA = not available
The asset list and other details are available from the water-dependent asset register and asset list (O'Grady and Bruce, 2016) and the asset database (Bioregional Assessment Programme, Dataset 1).
