Risks related to groundwater in the Murray Darling Basin

ABSTRACT Over the past 20 years, the consideration of risk related to groundwater in the Murray-Darling Basin has evolved from concerns about the impact of groundwater extraction on surface water resources to an integrated assessment of risks to connected Basin water resources. The Murray-Darling Basin Plan includes a comprehensive framework for assessing risks to Basin water resources. This assessment emphasises risks to surface water resources and does not fully consider or account for risks of depletion and degradation of groundwater resources and groundwater-dependent ecosystems. There are also risks relating to gaps in the implementation of integrated management of connected groundwater and surface water resources and storage. Consistent definition of hydrological connectivity is required together with longer planning timeframes. Multi-year planning rules and policies need to be further developed to exploit the full potential of integrated management of aquifer and surface water resources and storage to manage the risks of droughts and floods. The assessment in water resource plans of risks to subterranean groundwater-dependent ecosystems and terrestrial vegetation should be strengthened. Risks to groundwater quality must be adequately monitored and assessed to avoid harm to groundwater users. Further improvements can be made in the assessment of cumulative risks owing to coal seam gas and coal mining. Effective risk management requires collective scientific and policy efforts. Additional research can be targeted towards knowledge gaps and uncertainties that pose the greatest risk to groundwater resources and their use, and ecosystem viability. Most importantly, further training and capacity building in water management agencies is a critical requirement to enable effective and transparent monitoring and management of Basin water resources.