Oral Presentation NCGRT/IAH Australasian Groundwater Conference 2019

Groundwater management at the localised scale in the Murray-Darling Basin (181)

Tariq Rana 1 , Alice Shields 1 , Kristanne Mahony 1
  1. Murray-Darling Basin Authority, Canberra City, ACT, Australia

Groundwater systems which are subject to extraction require careful management to maintain resource sustainability at both the groundwater resource unit and local scale. To facilitate this process the Murray-Darling Basin Plan requires Basin state governments to develop Water Resource Plans (WRPs). WRPs must address a number of Basin Plan requirements to demonstrate that risks associated with groundwater extraction are minimised. However, because WRPs provide for water resource management at relatively large spatial scales, local scale issues may still occur within WRP areas. The nature of groundwater resources means that intense extraction in a localised area, while still within the Sustainable Diversion Limit volume, may result in unacceptable impacts. Therefore there may be a need for additional management actions to be put in place to address specific issues at smaller scales, such as localised groundwater drawdown.

Rules to manage a groundwater system based on resource condition limits (RCLs) allow specific needs of a groundwater system to be managed effectively and adaptively on a local scale to protect the environment, aquifer integrity, or hydraulic relationships between surface and groundwater resources. The Basin Plan ensures these rules will be brought forward into WRPs, and that a consistent, risk based approach is applied.

RCLs used in rules vary depending on the local needs, and may include volumetric limits on extraction, buffer distances around an environmental asset, aquifer drawdown limits or trigger levels, seasonal limits of water extraction, creating zones to limit entitlement or allocation, cease to pump rules and restrictions on water trading and bore density. Monitoring and adaptive management allow effective response to risks posed. Basin Plan requirements for a rule to be established is based on risk assessment, which requires analysis and interpretation of best available data and information for an area, and an adaptive management framework including monitoring, evaluation and reporting.