3.4.4.3 Potential ecosystem impacts

The zone of potential hydrological change in the vicinity of New Acland Coal Mine includes temporary streams and remnant vegetation associated with GAB aquifer outcrop areas. These temporary streams are likely to have fringing riverine vegetation communities that have some degree of groundwater dependence (Table 14). However, the regional groundwater model predictions indicate that median drawdown in the regional watertable under the baseline and due to additional coal resource development near New Acland Coal Mine is less than 0.2 m, with the exception of areas adjacent to New Acland Coal Mine Stage 2 operations (Figure 28). This suggests that these temporary streams, which flow through human-modified landscapes toward Lagoon and Oakey creeks and then into the Condamine River, are very unlikely to be impacted.

The north-eastern part of the zone of potential hydrological change near The Range coal mine overlies an area of Hutton Sandstone aquifer outcrop, which is predominantly remnant vegetation classified as ‘Non-floodplain, GAB GDE’ and watercourses classified as ‘Temporary, upland GAB GDE stream’. Median drawdown under the baseline in this area is less than 0.5 m and drawdown due to additional coal resource development is less than 0.2 m. Drawdown of this magnitude is in addition to and of a similar magnitude to natural watertable fluctuation (<2 m) (Table 12) for remnant vegetation in this area.

Temporary streams that are identified as GAB GDEs may include unidentified watercourse springs that access GAB aquifers. Median additional drawdown in excess of 0.2 m is predicted to affect up to 3 km of these streams, with most watercourses in this landscape group predicted to experience up to 0.5 m of baseline drawdown (Figure 29). Local impact assessment and modelling is required to provide more detail to supplement results from the regional model for communities where the critical thresholds identified in Table 12 for this landscape group are exceeded.


Last updated:
5 January 2018
Thumbnail of the Maranoa-Baloone-Condamine subregion

Product Finalisation date

2017
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