2.7.4.1 Description

2.7.4.1.1 Overview

The classification of the stream network in Section 2.3.3 of companion product 2.3 for the Galilee subregion (Evans et al., 2018) was based on catchment position, water regime, and water source. This classification produced 10 landscape classes. Of these, four classes are GDE streams (comprising the ‘Streams, GDE’ landscape group) and six are non-GDE streams (comprising the ‘Streams, non-GDE’ landscape group) (Table 9 in companion product 2.3 (Evans et al., 2018)). The streams landscape groups occur widely within the zone of potential hydrological change of the Galilee subregion (Figure 15). Of the 6285 km of streams in the zone, 2801 km (45%) are in the ‘Streams, GDE’ landscape group, whereas the majority (55% or 3484 km) is in the ‘Streams, non-GDE’ landscape group. Non-GDE streams are most prominent in the western and southern area of the zone (Figure 15).

The Galilee subregion straddles the Great Dividing Range and includes the headwaters of six major river basins. Much of the Galilee subregion lies in the Cooper Creek – Bulloo and Diamantina river basins (see companion product 1.1 for the Galilee subregion (Evans et al., 2014)). There are proposed coal seam gas projects in the Cooper Creek – Bulloo river basin, however, these projects are at a less advanced stage than coal mine developments and were unable to be quantitatively evaluated for this bioregional assessment (BA) (Section 2.3.4 of companion product 2.3 for the Galilee subregion (Evans et al., 2018)). Most of the proposed coal mine developments in the Galilee subregion are located in the Burdekin river basin, with the most advanced coal mine developments situated on the western side of the Belyando river basin. As a consequence, the zone of potential hydrological change of the Galilee subregion is focused on the Belyando river basin (Figure 16) and includes the Carmichael River, Belyando River Floodplain, Fox Creek, Sandy Creek and Native Companion Creek subcatchments (Dight, 2009).

Figure 15 Distribution of the streams landscape groups within the zone of potential hydrological change of the Galilee subregion, with location of selected stream gauges

River cross-sections and flow duration curves for the four stream gauges shown on this map are shown in Figure 17.

GDE = groundwater-dependent ecosystem

Data: Queensland Herbarium, Department of Science, Information Technology, Innovation and the Arts (Dataset 1); Geoscience Australia (Dataset 2)

Figure 16 Belyando River at Belyando Crossing in the Galilee assessment extent

Credit: Bioregional Assessment Programme, Chris Pavey (CSIRO), September 2017

2.7.4.1.2 Hydrological regimes and connectivity

Within the zone of potential hydrological change, mean annual potential evaporation far exceeds rainfall, particularly in the summer months (companion product 1.1 for the Galilee subregion (Evans et al., 2014)). Furthermore, rainfall is highly variable. These major components of the water balance assert a substantial control on the availability of surface water in the streams landscape groups of the zone. Limited available streamflow data suggest that surface water flows are variable in river systems within the zone (Figure 17).

Within the zone of potential hydrological change, annual streamflow shows a high degree of interannual variability (companion product 1.1 for the Galilee subregion (Evans et al., 2014)). Flows in a given year can vary from almost no flow to major floods, although there is at least some flow each year in the main river channels (Figure 47a of companion product 1.1 (Evans et al., 2014)).

Mean monthly flow is also highly variable. Most streams within the zone of potential hydrological change have prolonged no-flow periods each year (Dight, 2009). Flows vary greatly between months with minimal to no flow from July to October, while most flows occur between December and April (Figure 47b of companion product 1.1 (Evans et al., 2014)). The streamflow within the zone is thus characterised as one of dry seasonal flows (Figure 17).

Figure 17 River cross-sections (a) and flow duration curves (b) at stream gauges 120301 (Belyando River at Gregory Development Road), 120309 (Mistake Creek at Twin Hills), 120305 (Native Companion Creek at Violet Grove) and 120302 (Cape River at Taemas)

Stream gauge locations are shown in Figure 15.

Source: https://water-monitoring.information.qld.gov.au/ Accessed 1 February 2017

Surface water – groundwater connectivity in the Belyando river basin is thought to occur in a number of different ways. First, there is discharge from shallow groundwater systems to rivers. Another form of interaction is discharge from springs creating outflow pools in rivers. An example of this situation is where the outflow from Joshua Spring and the House Springs group (part of the Doongmabulla Springs complex) converge to provide the main discharge feeding the Carmichael River for a distance of up to 20 km (Fensham et al., 2016; see Section 2.7.3.1.1). There is also some discharge from groundwater systems to lakes (e.g. Lake Galilee and Lake Buchanan).

Groundwater may also be important in providing moisture for vegetation within the streams landscape groups. As an example, shallow groundwater (i.e. <20 m depth from surface to watertable) may be transpired by deep-rooted riparian trees such as river red gums and other GDEs (Section 2.3.2 of companion product 2.3 for the Galilee subregion (Evans et al., 2018)).

2.7.4.1.3 Ecological processes

The hydrological regimes and surface water – groundwater connectivity within the zone of potential hydrological change of the Galilee subregion result in surface water within the streams landscape groups being available for limited periods in any given year (Figure 17). A conceptual model for a riverine landscape with dry seasonal flows and groundwater – surface water connectivity, such as within the zone, is provided in Figure 18.

The dry seasonal flows of the streams within the Belyando river basin result in the ecosystems of the streams landscape groups being characterised by ‘boom–bust’ cycles. Specifically, diversity in the system is maintained by natural cycles of river flow and drying, driven by surface water inputs (Sternberg et al., 2015). Although more arid rivers further west in the Galilee assessment extent are driven by highly unpredictable rainfall, the ‘boom–bust’ cycle in the Belyando river basin is predictable and follows an annual hydrological cycle (Blanchette and Pearson, 2012, 2013). Ecological processes within this system operate in an environmental context where there is seasonally predictable summer rainfall which produces a resource pulse that is followed by a predictable period of drying. The drying phase is a relatively constant process in an average year uninterrupted by rainfall outside the summer period (Blanchette and Pearson, 2013).

During the months of high rainfall (generally between December and April), the dry rivers begin to flow and seasonally isolated water-dependent habitats (e.g. waterholes) are connected. This annual period of in-channel flow, or flow pulses, may be associated with large flood events producing overbank flow (see below) or it may occur independently in response to localised rainfall (Sheldon et al., 2010). Periods of very high rainfall, which occur infrequently, are responsible for large flood events. During these high rainfall periods, there is overbank flow and the environment becomes a large network of interconnected river channel and floodplain habitat (Figure 19). These overbank flooding events are used to identify the onset of the ‘boom’ phase in Australia’s dryland rivers (e.g. Sheldon et al., 2010).

During the ‘boom’ phase, aquatic and terrestrial productivity is high. Dispersal of freshwater fauna occurs during this phase and important life-history stages are completed. A large component of the aquatic fauna in this system and elsewhere in the Galilee assessment extent is capable of long-distance dispersal, with animals recolonising areas from distant waterholes once movement pathways are opened by flooding. Fish are a prime example of such a group (e.g. Kerezsy et al., 2013). At the end of the wet phase, all of the waterholes are likely to be replenished and exist at their most productive levels (Figure 19).

Figure 18 Conceptual model of a riverine landscape in the zone of potential hydrological change of the Galilee subregion, showing seasonal variation in streamflow

GDE = groundwater-dependent ecosystem

Source: adapted from Queensland Department of Science, Information Technology and Innovation (Dataset 3), © The State of Queensland (Department of Science, Information Technology and Innovation) 2015

Figure 19 Model of the 'boom-bust' dynamics of the streams landscape groups within the Galilee subregion zone of potential hydrological change, showing hydro-ecological associations over a range of flow conditions at the scale of the landscape (top) and an individual waterhole (bottom)

CTF = cease to flow

Source: Sternberg et al. (2015), Figure 1

Thus, the streams landscape groups of the Galilee subregion’s zone of potential hydrological change experience annual in-channel flows each summer and flood events at irregular intervals. The in-channel flows are important for maintaining connectivity and dispersal of aquatic organisms; however, they do not feature the high primary productivity of the flood events (Sheldon et al., 2010).

During the months of low or no rainfall (generally May to November), drying of the drainage system produces a series of waterholes and running reaches that have variable connectivity (Pusey and Arthington, 1996). Where the drying results in cease-to-flow events, shallow waterbodies dry out and chains of pools, isolated pools or completely dry riverbeds result, depending on riverbed morphology (Figure 19). As conditions continue to dry, evaporation will reduce the depth of each waterhole. Over time, productivity will change and the physico-chemical conditions decline. Changes occur in dissolved oxygen, conductivity, and pH (Blanchette and Pearson, 2013). Within the ‘Streams, GDE’ landscape group, groundwater inputs may be important to maintain waterholes during this ‘bust’ phase.

Waterholes during low-flow or no-flow periods tend to be characterised by high turbidity and limited light penetration. The aquatic food webs of these waterholes are typically driven by energy inputs from filamentous algae that form as a highly productive band in the shallow littoral margins. Phytoplankton blooms and zooplankton may also be important parts of the aquatic food web during the ‘bust’ phase. The algae, phytoplankton and zooplankton support large populations of snails, crustaceans and fish (Bunn et al., 2003).

2.7.4.1.4 Vegetation

Dominant canopy species in the riparian vegetation of the streams landscape groups include various eucalypts (Eucalyptus camaldulensis, E. coolabah and others), red bauhinia (Lysiphyllum carronii), whitewood (Atalaya hemiglauca), Melaleuca leucadendra and M. fluviatilis and several bloodwood (Corymbia) species including C. plena, C. dallachiana, C. erythrophloia and C. leichhardtii. The riparian regional ecosystems (REs) that occur within the zone of potential hydrological change include:

Overall, riparian vegetation within the Belyando river basin is considered to be in very poor condition and to have experienced a major decline over the last 30 years. This decline is mostly the consequence of floodplain clearing (Dight, 2009).

‘Brigalow (Acacia harpophylla dominant and co-dominant)’ which is listed under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) as an ‘Endangered’ ecological community, occurs within the streams landscape groups. This ecological community occurs patchily in the eastern half of the Galilee subregion’s zone of potential hydrological change (see companion product 3-4 for the Galilee subregion (Lewis et al., 2018)). The vegetation types that make up the Brigalow ecological community mostly occur on acidic and salty clay soils. Within the zone of potential hydrological change these are mostly on deep cracking clay soils. A small proportion of the Brigalow ecological community is associated with river and creek flats (Department of the Environment and Energy, 2017a).

2.7.4.1.5 Flora and fauna

Macrophytes are rare and macrophyte assemblages are poorly developed in the drainages along the zone of potential hydrological change of the Galilee subregion. As an example, sampling at three locations close to the zone during the assessment and benchmarking of key sentinel wetlands in the Burdekin river basin, Loong et al. (2005) failed to locate any macrophytes (Table 9). However, sampling as part of the proposed Carmichael Coal Mine environmental impact statement, GHD (2012a) located macrophytes in low diversity and abundance. Macrophytes were detected at one of five sampling sites along the Carmichael River, at one of three sites along Cabbage Tree Creek, at a gilgai site and at multiple dam sites (GHD, 2012a). Abundance was higher in Cabbage Tree Creek than in the Carmichael River. The macrophyte species present were Persicaria attenuata, Ottelia ovalifolia (swamp lily), Cyperus difformis (dirty dora), Cyperus sp., Monochoria cyanea, Myriophyllum sp. and Potamogeton sp. These species are typical of shallow or still water conditions in these parts of central Queensland.

Table 9 Presence of macrophytes in the Belyando river basin

Source: Loong et al. (2005)

Different dispersal strategies are used by animal species that have evolved to live in environments with ‘boom–bust’ dynamics such as the streams landscape groups of the Galilee assessment extent (Sheldon et al., 2010). Some species are mobile and move readily between suitable habitats irrespective of flow conditions. Examples of this strategy include Coleoptera (beetles) and Hemiptera (bugs). Another group, that includes crustaceans and some types of fish, disperses between waterholes during periods of streamflow. A third group, that includes snails, mussels and some fishes, exhibits little dispersal even when flow conditions are favourable (Sheldon et al., 2010). Streams within the zone of potential hydrological change support a wide range of fish and invertebrates such that each of these dispersal strategies is likely to be present.

Eleven species of fish have been recorded from the streams landscape groups within the zone of potential hydrological change. A further six species are predicted to occur within the zone (Table 10). None of the species are restricted to the Belyando river basin and each species has a large geographic range.

A diverse range of aquatic invertebrates occurs in the streams landscape groups within the zone of potential hydrological change. In general, available information on the taxa present is limited, thus further sampling is likely to identify the presence of additional taxa. Ten orders of invertebrates were recorded during sampling undertaken for environmental impact statements for many of the proposed coal mines within the Galilee subregion. Within the 10 orders, 48 families of aquatic invertebrates were identified. These included three families of decapod crustacean, eight families of beetle, three families of fly, three families of mayfly, ten families of bug, five families of dragonfly and damselfly, five families of caddisfly, two families of bivalve mollusc and four families of gastropod mollusc.

The streams landscape groups are important habitat for a range of threatened plants and vertebrate animals. The threatened species known or predicted to occur within the Galilee subregion zone of potential hydrological change are detailed below.

In parts of the zone the waxy cabbage palm is present in the riparian zone. It occurs in the lower Suttor and Belyando river basins (Pettit and Dowe, 2004; GHD, 2013a, 2013b). Within the zone, it has been recorded on the proposed Carmichael Coal Mine tenement along a 17.5 km stretch of the Carmichael River and associated tributaries (GHD, 2013b). Within the Carmichael River, waxy cabbage palms occur within the channel bed and on channel bars (GHD, 2013a). The species is listed as ‘Vulnerable’ nationally under the EPBC Act and under Queensland’s Nature Conservation Act 1992 (Nature Conservation Act).

The koala (Phascolarctos cinereus) occurs within the streams landscape groups in the Galilee subregion zone of potential hydrological change. Koalas in Queensland are listed as ‘Vulnerable’ nationally (EPBC Act) and under Queensland legislation (Nature Conservation Act). Koalas in semi-arid environments, including the zone, inhabit forest and woodland dominated by Eucalyptus species with important food and habitat trees including Eucalyptus camaldulensis, E. populnea, E. crebra, E. tereticornis, E. melanophloia, E. tessellaris and Melaleuca bracteata (Gordon et al., 1988; Ellis et al., 2002). Eucalyptus camaldulensis is the dominant tree in several of the regional ecosystems within the streams landscape groups (see Section 2.7.4.1.4). Koalas occur in riparian E. camaldulensis woodland along Tallarenha Creek on the South Galilee Coal Mine development (MET Serve, 2012a, 2012b). In semi-arid Queensland, riparian vegetation along drainage lines is considered to be an important refuge area for koalas during droughts (Sullivan et al., 2002 cited in Department of the Environment and Energy, 2017b).

Table 10 Summary of fish species recorded during surveys for environmental impact statements at five proposed coal mine developments in the Galilee subregion zone of potential hydrological change

✓ indicates the species was recorded at the location, * indicates the species is predicted to occur at the location, x indicates the species was not recorded at the location. Scientific names for each species are shown in italics below each common species name.

Source: Environmental impact statements for Alpha (Hancock Prospecting Pty Ltd, 2010), Carmichael (GHD, 2012a), China Stone (Cumberland Ecology, 2015), Kevin’s Corner (Hancock Galilee Pty Ltd, 2011) and South Galilee (ALS Water Resources Group, 2011)

The ornamental snake (Denisonia maculata) occurs within the zone of potential hydrological change. The species is listed as ‘Vulnerable’ under both the EPBC Act and the Nature Conservation Act (Department of the Environment and Energy, 2017c). Within the zone, it will potentially occupy all four of the broad landscape groups but is most likely to occur in the streams landscape groups and ‘Floodplain, terrestrial GDE’ landscape group. The ornamental snake is considered to be water-dependent as it feeds almost exclusively on frogs. It occurs in riparian vegetation along watercourses, on the margins of wetlands including lakes and swamps and in terrestrial vegetation that is likely to be groundwater-dependent. The latter category includes woodland and open woodland of coolibah (Eucalyptus coolabah), poplar box (E. populnea), brigalow (Acacia harpophylla), gidgee (A. cambagei) and blackwood (A. argyrodendron) (Department of the Environment and Energy, 2017c). The REs in which it has been found all have clay soils. These REs include 11.4.3, 11.4.6, 11.4.8 and 11.4.9 (Department of the Environment and Energy, 2017c).

The yakka skink (Egernia rugosa) is a threatened lizard that occurs within the Galilee subregion zone of potential hydrological change. It is listed as ‘Vulnerable’ under both the EPBC Act and the Nature Conservation Act (Department of the Environment and Energy, 2017d). The species occurs in woodland and open forest dominated by a range of trees including species of Acacia, Eucalyptus, Casuarina and Callitris spp. Yakka skinks are burrowing animals that occur in colonies or small groups (Chapple, 2003). Within the zone the yakka skink is likely to occupy sand plains, clay and clay loam plains, sandstone rises and minor pediments and vegetation fringing watercourses and stream channels and on alluvial plains. Therefore, it is expected to occupy the streams landscape groups. Potential habitat includes riparian vegetation along the Carmichael River and Cabbage Tree Creek on the Carmichael Mine site (GHD, 2012b). The water-dependency of the species is poorly understood.

The southern subspecies of the squatter pigeon (Geophaps scripta scripta) is listed as ‘Vulnerable’ under both the EPBC Act and the Nature Conservation Act (Department of the Environment and Energy, 2017e). It is a granivorous bird that occurs through much of the Galilee subregion zone of potential hydrological change. It was recorded during surveys as part of the environmental impact statements for five of the major coal mine developments in the zone. From north to south these are China Stone, Carmichael, Kevin’s Corner, Alpha and China First. The squatter pigeon (southern) forages and breeds in a range of open-forest, woodland and open-woodland vegetation types that have a grassy understory. It depends on surface water as it needs to drink on a daily basis and, as a consequence, foraging and nesting sites are located within 3 km of a water source. Water sources used by the species include rivers, lakes and artificial sources such as farm dams (Department of the Environment and Energy, 2017e). Therefore, the squatter pigeon uses water sources within the streams landscape groups.

The red goshawk (Erythrotriorchis radiatus) is listed as ‘Vulnerable’ nationally (EPBC Act) and ‘Endangered’ in Queensland (Nature Conservation Act). The range of this species includes small areas of the zone of potential hydrological change within the Galilee subregion. The species can be considered to be water-dependent because of the nest sites it uses. Nests are constructed in tall trees (mean height of 31 m) that are located within 1 km of, and commonly beside, permanent water. Water sources include rivers, swamps and pools (DERM, 2012). Given this nesting preference, the red goshawk is likely to occur within the streams landscape groups.

The eastern/southern subspecies of the star finch (Neochmia ruficauda ruficauda) is classified as ‘Endangered’ nationally (EPBC Act) and in Queensland (Nature Conservation Act). However, an assessment of the conservation status of all Australian bird taxa in 2010 concluded that its status should be critically endangered (possibly extinct) (Garnett et al., 2011). The star finch (eastern) may previously have occurred in the Galilee subregion zone of potential hydrological change; however, there are no confirmed records (Department of the Environment and Energy, 2017f). The star finch needs surface water from which it drinks daily. It occupies grassland and grassy woodland close to freshwater, in particular in riverine habitats (Garnett et al., 2011). Within the zone it is most likely to occur in the streams landscape groups.