As a South Australian, I agree.

It is said that the lower Murray lakes seep or evaporate up to 1000 GL a year. That demand has recently been compounded by pumping fresh water from Lake Albert to the hypersaline Coorong which is the long lagoon to the south east. Check it out on Google Earth.

The barrages were built as a 1930s work-for-the-dole scheme and were set at about 75 cm above the then sea level. If sea level rises about 4 mm a year it will eventually overtop the lake barrages and the Coorong lagoon decades from now. The lakes themselves are not used that much for recreation. I've been around them in canoes, sailboats and power boats. If the barrages were simply left open (no demolition required) the initial effect would a lowering of the lake levels. Acid drainage that some fear would eventually neutralise.

I understand that nearby farming uses a pipe from well upstream on the Murray at Tailem Bend to guarantee lack of salinity. A salt barrier weir would be needed near Wellington at the end of the main river channel. The mud base may mean it has to be porous. As with now a navigation channel would be marked down to the town of Goolwa.

Given Australia's high population growth and proneness to drought it is entitled and wasteful for SA to claim the lower lakes and Coorong have a legitimate need for 'environmental' water. A couple a years ago SA tried to sool a Royal Commission onto NSW (where the rain actually falls) for using too much water. It beggars belief.

We can irrigate twice current allocation for half the allocation! Needs all be done underground via tapes. And if we had nuclear waste burning MSR, we could pump millions of nutrient loaded waters for additional production. All storage must be covered, which will add another 50% currently lost to evaporation.
Alan B.

It'll be another decade or more before the experts wake up !