Cumulative impacts on streamflow from potential groundwater extraction under MDB Plan from NCGRT on Vimeo.
Cumulative impacts on streamflow from potential groundwater extraction under MDB Plan
Presented by: Dr Glen Walker
Cumulative impacts on streamflow from potential groundwater extraction under the Murray-Darling Basin Plan: a preliminary risk assessment.
Under the Murray-Darling Basin (MDB) Plan, sustainable diversion limits (SDLs) have been set for groundwater resources across the whole of the MDB and at a range of depths. The resulting aggregate SDL for the MDB (3494 GL) is much greater than the mean annual groundwater extraction for the period 2003-2017 (1335 GL) and hence would allow increases in extraction to meet future demands. Any increase in groundwater extraction may reduce surface water flow and potentially undermine the surface water SDLs, a key outcome of the Basin Plan. In response to this concern, University of Melbourne was asked to review the potential risk of increased extraction. A preliminary risk assessment was conducted for the cumulative impact of groundwater extraction on streamflow within 40 years under different scenarios of increased groundwater extraction. The baseline condition is no evident increasing trend for groundwater extraction during the period 2003-2017. The talk will describe the methodology, which had developed in various studies over 15 years; the results of the assessment; and the implications for management.
Glen Walker has conducted groundwater and salinity research for over 30 years with CSIRO in Adelaide. Specific research interests included recharge and discharge, vegetation and salinity, catchment modelling for salinity management, groundwater-surface water interactions and climate impacts on groundwater. He also led the groundwater component of the Murray-Darling Basin Sustainable Yields project and is a recipient of WE Woods Award for National Excellence in Salinity Research. Since his retirement from CSIRO in 2014, Glen has been consulting with his company, Grounded in Water, and is a member of the Independent Scientific Expert Committee for Coal Seam Gas and Large Coal Mining Development.