Once the assets were identified and compiled into the asset database and it was confirmed the assets were encompassed within the PAE, they were assessed for water dependence. All assets in the asset list that may be potentially impacted by changes in the groundwater or surface water regime (i.e. changes in the quality and quantity of surface water and groundwater) were identified. Although most of the assets will be clearly ‘water dependent’ in the general sense of the phrase (e.g. groundwater bores, rivers and wetlands), there is a small group of assets that could be affected but are not as readily identified as being ‘water dependent’. Examples of these assets include historical buildings that may be potentially subject to inundation or salinity impacts, or Indigenous assets that may be more difficult to access due to changes in the water regime.
It is important to emphasise that BAs consider the potential impact to the habitat of species not the individual species per se. However, it is necessary to present species-based information to best reflect the available data; but implicit in this is the focus on habitat.
The preliminary version of the water‑dependent asset register, with associated maps and data, were presented to experts and organisations with technical expertise of the Gippsland Basin bioregion BA asset workshop in Traralgon on 1 December 2014 for comment and feedback. Fourteen local participants from relevant state and local governments attended (Table 5). They identified a number of shortfalls and subsequently provided data to amend the register. Some of the issues raised and actions identified are presented in Table 6.
Table 5 Organisations represented at the bioregional assessment asset workshop held in Traralgon, Victoria on 1 December 2014
Table 6 Summary of issues raised by participants at the asset workshop held in Traralgon, Victoria on 1 December 2014 and actions for the Assessment team of the Gippsland Basin bioregion
The water dependency of threatened species assets or habitats was assessed by review of the habitat requirements for each species. In most cases profiles from the Species Profile and Threats Database (SPRAT) (Australian Government Department of the Environment, Dataset 14) were examined. The water dependence of each species-related asset was ranked as being ‘likely’, ‘possible’, ‘unlikely’ or ‘potential’. Assets listed as ‘likely’ are those with a clear and demonstrated link to aquatic ecosystems (e.g. aquatic species). Assets listed as ‘possible’ may have some overlap with habitats that may be water dependent (e.g. species that may visit riparian areas). Assets listed as ‘unlikely’ show no water dependence in habitat requirements.
Species listed under Victoria’s Flora and Fauna Guarantee Act 1988 and the Victorian Department of Environment, Land, Water and Planning threatened species advisory list for areas covering East and West Gippsland CMAs were considered for inclusion in the asset database. However, there is currently insufficient habitat modelling information to make definitive determinations of:
- their occurrence within the PAE
- habitat requirements within the PAE.
As there was no available spatial information related to the distribution of assets associated with species and their habitats, they are recognised as being ‘potential’ assets but require further investigation before they can be included in the water‑dependent asset register.
A preliminary assessment of the water dependency of vegetation assets was made using the following assumptions:
- Riparian vegetation was assumed to be water dependent (attributed as ‘likely’).
- Vegetation assets that intersect with the maximum floodplain extent were assumed to be water dependent (attributed as ‘likely’).
- Vegetation assets outside the maximum floodplain extent mapping, where groundwater was less than 10 m from the surface, were assumed to be water dependent (attributed as ‘likely’).
- Vegetation assets derived from the ‘Groundwater-dependent ecosystem’ class with a known groundwater dependency derived from previous field work or a high potential for groundwater dependency were assumed to be groundwater dependent (attributed as ‘likely’). Assets with a moderate potential for groundwater dependency were attributed as ‘possible’. Vegetation assets sourced from the National atlas of groundwater dependent ecosystems (GDE Atlas) (Bureau of Meteorology, 2012; Bureau of Meteorology,Dataset 4) with a low probability for groundwater dependence were given an attribution of ‘unlikely’.
- Vegetation assets which intersect surface water features were assumed to be water dependent (attributed as ‘likely’).
- Vegetation assets which are located over shallow groundwater (i.e. watertable is less than 10 metres below ground level) were assumed to be water dependent (attributed as ‘likely’).
All non-vegetation based assets in the ‘Surface water feature’ and ‘Groundwater feature (subsurface)’ classes of the asset database were assumed to be water‑dependent assets and attributed as ‘likely’. Figure 3 shows the spatial coverage of the 100-year flood extent and regions where the watertable is within 10 m of ground surface.
Assets attributed as ‘likely’ or ‘possible’ are considered further in the BA and flagged as ‘yes’ with respect to water dependency in the asset database; assets attributed as ‘unlikely’ are flagged as ‘no’ in the asset database and are not considered further in the BA. Where uncertainty existed in relation to water dependence of an asset, a cautionary approach was taken and the asset was included in the water-dependent asset register.
Once water dependence was determined and the decisions recorded in the asset database, a preliminary version of the water‑dependent asset register was generated from the asset database and presented to experts and organisations with local knowledge at the BA assets workshop for comment and feedback.
The characteristics of the groups of water‑dependent assets identified in the Gippsland 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.
The water‑dependent asset register is a simple and authoritative listing of the names of the assets that will be included in other components of the BA; all the geographic and other data associated with each asset (including for each element) is stored in the asset database. Other BA components are described in the BA methodology (Barrett et al., 2014) including the companion submethodology M03.
