Assessing water dependence

Assets in the asset database that intersect the PAE of the Sydney Basin form the asset list for the Sydney Basin bioregion. The water dependency of each asset in the asset list must then be assessed. Only assets that have a water dependency qualify for inclusion in the water-dependent asset register. Thus any asset that might potentially be affected by changes in the groundwater and/or surface water regime due to coal resource development is added to the water-dependent asset register. Many assets are clearly ‘water dependent’, including all economic assets (i.e. water access entitlements and reservoirs).

For ecological assets, features such as rivers, wetlands, lakes, lagoons and groundwater-dependent ecosystems are clearly water dependent; however, the water dependency of other assets, such as nature reserves and conservation areas, is less certain. The water dependency of nature reserves and conservation areas was determined based on their intersection with obvious surface water and groundwater features. Assets that do not overlap with obvious water features were judged not to be water dependent. The water dependency of threatened species and communities were assessed on a case-by-case basis, based on their profiles in the Species Profile and Threats Database (SPRAT) (Australian Government Department of the Environment, Dataset 10; Bioregional Assessment Programme, Dataset 11) and the NSW BioNet website (NSW Office of Environment and Heritage, 2016).

A similar approach was taken to judge the water dependency of sociocultural assets. The water dependency of sociocultural assets is not always obvious, so it was assumed that within some specified distance of a water feature, there is the potential for changes in groundwater table or streamflow regime to impact the assets. A 500 m buffer (i.e. the same buffer width used to define the area around streams where surface water and groundwater potentially interact (see section and Figure 12)) – was put around all rivers and wetlands, and this was intersected with the sociocultural assets to identify those having a potential water dependency.

Water dependence was determined for a preliminary list of assets to produce a preliminary version of the water-dependent asset register. For transparency, decisions about water dependency are recorded in the asset database. The preliminary version of the water-dependent asset register, with associated maps and data, was presented to experts and organisations with local knowledge at the Sydney Basin asset workshop in Penrith (NSW) in August 2015 for comment and feedback. There were 14 participants from state and local governments and 10 participants from Commonwealth agencies and the Assessment team (Table 17). The participants demonstrated an enormous willingness to provide additional or better data to improve the water-dependent asset register for the subregion.

Most participants had seen the preliminary list of assets prior to the workshop and had already identified missing datasets. There were very few issues raised on the day and the discussions were mostly around additional data that could be made available. They are summarised in Table 18, together with the BA response to these issues.

Following the workshop, three weeks was allowed to follow up additional datasets from the local government and state agencies. Where datasets were deemed fit-for-BA purpose and the assets were within the PAE, they were added to the water-dependent asset register.

More details about the ecological, economic and sociocultural water-dependent assets identified in the Sydney Basin bioregion, and the reasons for their inclusion or exclusion from the water-dependent asset register, are described in Section 1.3.2, Section 1.3.3 and Section 1.3.4 respectively.

The water-dependent asset register is an authoritative listing of the assets that will be included in other components of the BA; all spatial data and other data associated with each asset are stored in the asset database.

Table 17 Organisations represented at the Sydney Basin bioregion asset workshop held in Penrith on 24 August 2015


Number of participants



Department of the Environment – Environmental Resources Information Network


Department of the Environment – Office of Water Science


Bureau of Meteorology


NSW Office of Environment and Heritage


NSW Department of Primary Industries, Fisheries


NSW Department of Primary Industries, Water




Greater Sydney Local Land Services


Southeast Local Land Services


Central Tablelands Local Land Services


Wollondilly Shire Council


Blue Mountains City Council


Campbelltown City Council




Table 18 Issues and comments from the Sydney Basin bioregion asset workshop and actions for the Assessment team





WaterNSW: Greater Sydney water supply catchments are not specifically included as an asset.

Four water supply catchments were defined based on water source areas in the Greater Metropolitan Region Unregulated water sources WSP.


Greater Sydney LLS: missing some surface water GDEs

OEH: NSW Wetlands (2006) layer will not include a lot of upland swamps. Other sources available (Macquarie University; OEH may have data; Centennial Coal mapping)

’National Groundwater Dependent Ecosystems (GDE) Atlas’ (Bureau of Meteorology, Dataset 3) includes some upland swamps. No other mapped data obtained. This is potentially a data gap, but some may also be covered by other spatial layers in the asset register.

Greater Sydney LLS: have vegetation layer that covers all freshwater wetland endangered ecological communities

Two data layers were supplied: OEH (Dataset 22) and NSW Office of Water (Dataset 27).

OEH: mapping of EPBC Act-listed species is highly uncertain

Noted. This is acknowledged as a data limitation in Section 1.3.2 .

OEH: individual rivers and creeks are not identified as assets. Grose and Colo are examples of wild rivers. OEH have statewide data layer of Wild Rivers

Geofabric rivers cover river assets, but Colo and Grose have been specifically added as assets (Dataset 33).

OEH: recharge areas for GDEs (e.g. Birds Rock Flora Reserve; Agnes Banks woodland)

Recharge areas are part of the causal pathway, but not water-dependent assets under the BA definition. If changes occur from mining that affect recharge areas, conceptual and/or numerical modelling will reflect this connectivity.

OEH: raised question of connectivity between Thirlmere Lakes and groundwater (i.e. should it be listed as a GDE?)

Regardless of the connectivity, it meets BA criteria for water dependence – it is a lake. It is included in five of the asset datasets: DIWA (Dataset 2), CAPAD (Dataset 7), NSW Wetlands (Dataset 4), WAIT database (Dataset 6), Register of the National Estate (Dataset 42).

DPI: are caves included? Not part of National Atlas Wetlands or NSW wetland mapping

Gardens of Stone National Park is in CAPAD dataset (Dataset 7) and includes Coco Creek, Blue Rock karst systems. They have been added as point features to the water-dependent asset register (NSW Office of Water, Dataset 27)

DPI Fisheries: threatened fish

Fitzroy Falls spiny crayfish, Macquarie Perch, Purple spotted gudgeon added (DPI, Dataset 23; DPI, Dataset 24; DPI, Dataset 25)

Platypus should be included

Iconic species. Identified as an asset at Gloucester, Hunter and Sydney Basin workshops. Included in WAIT_ALA_ERIN dataset (Dataset 17)


Greater Sydney LLS: Brad Moggridge was commissioned by Hawkesbury-Nepean CMA to do a study of Indigenous water assets

Report supplied (Moggridge, 2010) and assets within PAE included in asset list (Bioregional Assessment Programme, Dataset 1)

OEH: EISs include Indigenous/cultural info (e.g. Russell Vale has some important sites)

Office of Water Science have a process for pursuing Indigenous assets as part of BA. Mining reports have not informed the asset list for sociocultural assets.

OEH: are rivers with recreational values (e.g. used for canyoning) included?

All Geofabric rivers are included in the water-dependent asset register (Dataset 33). Can have multiple values

Coco Creek – sociocultural significance

In asset list as a geological feature of significance (karst) (NSW Office of Water, Dataset 27)

BA = bioregional assessment, CAPAD = Collaborative Australian Protected Areas Database, CMA = catchment management authority, DIWA = A directory of important wetlands in Australia, DPI = New South Wales Department of Primary Industries, EPBC Act = Commonwealth’s Environment Protection and Biodiversity Conservation 1999, EIS = environmental impact statement, GDE = groundwater-dependent ecosystems, OEH = Office of Environment and Heritage, PAE = preliminary assessment extent, WAIT = Water Asset Information Tool, WSP = water sharing plan

Last updated:
21 January 2019