The Draft Basin Plan was released by the Murray-Darling Basin Authority (MDBA) for consultation in November 2011. As part of the development of the South Australian Government response, a scientific review was undertaken to assess the hydrological and ecological consequences of the proposed 2750 GL water recovery scenario on key ecological assets for South Australia.
This report presents an analysis of MDBA modelling and examines the potential implications of the proposed 2750 GL water recovery scenario for the Murray Mouth, the Coorong and its biota over the 114-year period modelled by the MDBA in its development of the Draft Basin Plan. As far as possible, analysis was also undertaken on the 2400 GL and 3200 GL sensitivity analysis provided by the MDBA.
The MDBA provided the outputs of a number of the modelling simulations it undertook for analysis by the South Australian Government. The analyses of the MDBA hydrological modelling outputs undertaken by DENR, which forms the basis of this report, assessed the impacts on three ecological drivers, which have been shown to be related to the distribution and abundance of macroinvertebrates, fish, birds and submerged aquatic plants in the Coorong, namely:
1. Murray Mouth 'openness‘
2. Coorong salinity
3. Coorong water levels.