Knowledge of the location of subterranean faults and fractures of the geological layers that can affect flow paths is the greatest knowledge gap. This means it is more difficult to identify where even the largest faults can affect the ‘Subsurface depressurisation and dewateringand ‘Subsurface physical flow paths causal pathway groups. For example, the location of faults in the subregion and their nature, location and extent of smaller potential pathways between adjacent layers is not known at a regional scale. This means that uncertainty exists in the precise spatial extent of groundwater level decline due to CSG operations. However, the uncertainty analysis undertaken for the numerical groundwater modelling does allow a probabilistic estimate of maximum groundwater level decline, as described in the groundwater numerical modelling (companion product 2.6.2 for the Maranoa-Balonne-Condamine subregion (Janardhanan et al., 2016)).

The availability of long-term, consistent water quality and water quantity data measurements of surface water and groundwater systems limits the value of developing a coupled surface water-groundwater numerical model in the Maranoa-Balonne-Condamine subregion for BA at this time. Data availability issues will be addressed through the assessment of risks to water quality and identification of water quality targets based on local data (including electrical conductivity, nutrients, turbidity, pH) in the development of the Healthy Waters Management Plans under Queensland’s Environmental Protection Act 1994 legislation and the Commonwealth’s Basin Plan 2012 (MDBA, 2012). The water quality targets developed for the plans will assist in informing regulatory conditions on environmentally relevant activities such as CSG operations and coal mines.

Last updated:
16 October 2018
Thumbnail of the Maranoa-Baloone-Condamine subregion

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