The facts are very unpleasant, but very clear. Long term, there is insufficient freshwater in the Murray-Darling Basin to support sufficient environmental flows to the Lower Lakes. Climate change and the predicted falls in total Murray-Darling Basin inflows combined with increasing human consumption will only make the problem worse (read the CSIRO reports).
The water problems of the Murray Darling basin combine issues of drought, politics and over-extraction, but the Coorong and the Lower Lakes have an additional man-made problem. The Goolwa Barrages that were constructed in 1940 create an artificial barrier between the sea and the River Murray. The resulting freshwater ecosystem, that we have been enjoying for 70 years, is totally dependent on government managed freshwater flows from the River Murray to artificially keep the Lower Lakes at the full supply level of .75m above sea level.
We believe the water problems of the Lower Lakes can and should be decoupled from the rest of the problems of the Murray-Darling Basin by virtue of the Lower Lakes' proximity to the sea. By opening the barrages to let in seawater, the River Murray estuary can be restored. Additionally, in times of low river flows, environmental flows can be conserved for damaged wetlands up river that do not have the option of the sea.
We therefore advocate:
Opening the barrages to restore the River Murray estuary to its natural state.
Longer term, the following options merit further consideration:
Construction of a weir near Wellington, to conserve freshwater in the River Murray and protect South Australia's fresh water supply.