Once assets were compiled into the asset database and checked for inclusion in the PAE, they were assessed for water dependence. Although most nominated assets are, by definition of their database sources, 'water dependent' (e.g. groundwater bores, rivers, lakes and wetlands), there are a number of types of assets that are less clearly 'water dependent' (e.g. a national park with a varied landscape, the habitat of a non-aquatic species and historical places). Because of the diversity of asset types, the spectrum of degrees to which assets might be water dependent, and the need for all assessment decisions to be transparent and recorded, a highly structured, formal approach was developed for assessment of water dependency.
Six principles form the foundation of the approach to assessment of water dependence of assets in the Galilee PAE:
- Efficiency. The methods are suitable for effective application to large numbers of assets.
- Transparency. All decisions in assessments are tracked, including their rationales, any data sources and dates of assessments.
- Rigour. Decision making is based on sound ecological, economic and sociocultural principles and clear logic, and able to withstand close peer and expert scrutiny.
- Multiple lines of evidence. Wherever possible, assessment decisions are based on as many sources of information about water dependence as possible. Three broad groups of evidence are used: (i) asset naming conventions, (ii) documents describing asset management and (iii) GIS and remote sensing databases containing layers that directly or indirectly quantify surface water and groundwater availability.
- Precaution. Where part of an asset is water dependent, the entire asset is assessed as water dependent. Where there is inconclusive evidence, assessment decisions consistently err on the side of assuming potential water dependence (i.e. if one data source indicates water dependence, then the overall decision across the multiple lines of evidence is water dependence). On this basis, the maximum number of assets is retained within the database for subsequent analysis of potential development impacts.
- Separate tracking of assessment for dependence on groundwater and surface water. Later stages of the BA impact analysis are likely to demonstrate separate causal pathways for potential impact of coal resource development via surface water and groundwater systems. If that proves to be the case, then potential for impact on an asset via the surface water or groundwater pathway will only be true if the asset depends on the corresponding above or below-ground water resource (Figure 4).
This report focuses exclusively on assessment of water dependence i.e. the upper part of this logic. Future bioregional assessments for the Galilee subregion will assess hydrological connectivity and response, and thus the potential for impact on assets.
For some asset sources, the only direct information available for assessing water dependence of each asset is its name. The Environmental Assets Database (EAD), Great Artesian Basin Groundwater Recharge Beds database and the Key Environmental Assets (KEA) of the Murray-Darling Basin are databases in which little asset data other than name and geographic coordinates are available. The Queensland groundwater and surface water licensing from the water management system databases are also restricted in terms of information other than asset name and type.
Two simple naming criteria were used to assess water dependence for assets of these types:
- if asset name includes ‘spring’, ‘soakage’, ‘bore’, ‘groundwater’, etc., then the asset is groundwater dependent
- if asset name includes ‘river’, ‘stream’, ‘floodplain’, ‘waterhole’, ‘billabong’, ‘lake’, ‘wetland’, ‘marsh’, ‘surface water’, etc., then the asset is surface water dependent.
Although initially developed for specific, information-poor data sources, these rules were subsequently applied to all assets in the asset list, regardless of data source.
Most assets sourced from the Collaborative Australian Protected Area Database (CAPAD), A directory of important wetlands in Australia (DIWA), the Ramsar List of Wetlands of International Importance and EPBC threatened ecological communities (EPBC TEC) are subject to legislatively required management plans that include some degree of ecosystem description. For these assets, management plans and/or asset descriptions were obtained from federal and Queensland agencies. The management plans and their constituent ecosystem descriptions were then subjected to text analysis, using the following simple criteria to assess water dependence:
- if ecosystem description includes ‘spring’, then asset is groundwater dependent
- if ecosystem description includes any ecosystem type, community type, habitat type or dominant species and has been identified in any published literature as accessing groundwater (e.g. river redgum, coolibah (Eucalyptus coolabah), black box (Eucalyptus largiflorens), fish species), then asset is groundwater dependent
- if ecosystem description includes ‘riverine vegetation’, ‘floodplain’, ‘waterhole’, ‘billabong’, ‘lake’, ‘wetland’, ‘marsh’, etc., then asset is surface water dependent
- if ecosystem description includes any ecosystem type, community type, habitat type or dominant species known to access surface water (e.g. river redgum, coolibah, black box, lignum, most waterbird species, fish), then asset is surface water dependent.
The water dependency of threatened species’ habitats, including threatened species listed under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and under Queensland’s Nature Conservation Act 1992 (Nature Conservation Act), was assessed by a review of the habitat requirements for each species. It is important to emphasise that BAs consider the potential impact to the habitat of species, not to the population of the species per se. In most cases, profiles from the Species Profile and Threats Database (SPRAT) (Australian Government Department of the Environment, Dataset 23) and the Queensland Government’s WetlandInfo website were examined.
Any information suggesting that water dependence was ‘certain’, ‘likely’ or ‘possible’ was interpreted as ‘water dependent’ for the purposes of the asset register.
Criteria based upon asset naming and upon available, published asset descriptions and management plans proved to be inadequate for satisfactory assessment of water dependence in a large proportion of assets. Other sources of information were sought to expand the range of data available for assessment of asset water dependence.
Six mapped GIS and remote sensing data layers were identified as providing additional information relevant to assessing dependence on surface water or groundwater. GIS analyses were used to spatially intersect each asset with each of the six data layers. If any part of an asset was found to overlap with any one of these layers, that observation was used as evidence for water dependence, according to the precautionary principle previously described.
The six data layers were:
- Groundwater-dependent ecosystems reliant on subsurface presence of groundwater, derived from the National atlas of groundwater dependent ecosystems . Subsurface presence of groundwater is defined as groundwater that contributes to the soil water and near-surface aquifers accessible to plant roots without generating a flow of water at the soil surface. Only those GDEs derived from previous field work or possessing a high or moderate potential for groundwater dependency were used in the intersection. Positive intersection of an asset with this layer indicates potential dependency on groundwater. A map of this data layer across the Galilee PAE is shown in Figure 5.
- Groundwater-dependent ecosystems reliant on surface expression of groundwater, derived from the National atlas of groundwater dependent ecosystems . Surface expression of groundwater is defined as groundwater that flows at the soil surface in the form of a spring or seep, including those springs that lie under surface water bodies such as streams, waterholes, lakes or swamps, for which the primary source of water may be from surface flows. Only those GDEs derived from previous field work or possessing a high or moderate potential for groundwater dependency were used in the intersection. Positive intersection of an asset with this layer indicates potential dependency on groundwater and/or surface water. A map of this data layer across the Galilee PAE is shown in Figure 6.
- Wetlands defined according to the Queensland Government’s regional ecosystems classification . Positive intersection of an asset with this layer indicates potential dependency on groundwater and/or surface water. These data are not available for the parts of the PAE that lie in SA. A map of this data layer for the Queensland parts of the Galilee PAE is shown in Figure 7.
- Mean annual evapotranspiration in excess of incident rainfall across the Galilee PAE . This layer is calculated as the difference between actual evapotranspiration assessed through remote sensing techniques during 1992 to 2011 and a predicted model of evapotranspiration if water were sourced only from incident rainfall. A positive difference means that long-term observation of the amount of water released into the atmosphere by plant evapotranspiration exceeds the inputs of water from rainfall, and the vegetation is accessing additional water from groundwater pools or contributions to soil water. These contributions to soil water result from surface water flowing from elsewhere in the catchment; however, the data are not able to be interpreted to indicate whether the additional water is from a groundwater pool or surface water flow. Thus, intersection of an asset with high excess evapotranspiration values in this layer indicates potential dependency on groundwater and/or surface water. A map of this data layer across the Galilee PAE is shown in Figure 8.
- The percentage of time water was observed during 1987 to 2015, from the Water Observations from Space database (Bioregional Assessment Programme, Dataset 27). Positive intersection of an asset with higher percentage inundation classes in this layer indicates potential dependency on surface water. A map of this data layer across the Galilee PAE is shown in Figure 9.
- The distribution of riparian vegetation potentially intersecting groundwater (Bioregional Assessment Programme, Dataset 28). This layer summarises the results of an analysis of remote sensing data to measure evapotranspiration rates towards the end of a prolonged period of below average rainfall. Positive intersection of an asset with this layer indicates potential dependency on groundwater. A map of this data layer across the Galilee PAE is shown in Figure 10 .
Application of this approach is demonstrated for a single asset in the Galilee PAE, Lochern National Park, in Figure 11 and Figure 12. Lochern National Park sits immediately to the west of the Thomson River (see Figure 10). All six GIS and remote sensing layers provide clear evidence for dependence on groundwater and/or surface water along the main channels of the Thomson River. Therefore, this asset is assessed to be water dependent and is included in the register of water-dependent assets. However, it is important to note that away from the channels, each of the six layers provides evidence for different patterns of potential water dependence. Therefore the six layers provide independent and complementary lines of evidence for the assessment of asset dependence on water.
Data: Bureau of Meteorology (Dataset 8)
Data: Bureau of Meteorology (Dataset 8)
Data: Bioregional Assessment Programme (Dataset 25)
Data: Bioregional Assessment Programme (Dataset 26)
Data: Bioregional Assessment Programme (Dataset 27)
Data: Bioregional Assessment Programme (Dataset 28)
Figure 11 Spatial intersection of a specific asset, Lochern National Park, with layers of (a) mean annual evapotranspiration in excess of incident rainfall, (b) groundwater-dependent ecosystems reliant on subsurface presence of the water and (c) groundwater-dependent ecosystems reliant on surface expression of the water
Figure 12 Spatial intersection of a specific asset, Lochern National Park, with layers of (a) percent duration of time water was observed, (b) wetlands according to the Queensland Government's regional ecosystems classification and (c) riparian vegetation potential intercepting shallow groundwater
Product Finalisation date
- 1.3.1 Methods
- 1.3.2 Ecological assets
- 1.3.3 Economic assets
- 1.3.4 Sociocultural assets
- Contributors to the Technical Programme
- About this technical product