Now the South Australian town of Goolwa wants some of it downstream to flush out the salt and acid turning the Murray mouth into a stinking bog.

In a country gripped by drought and climate change, the stricken SA community wants to use water reserves that flowed into NSW from the summer Queensland floods.

Menindee Lakes, on the Darling River, is under half its capacity, with the two largest lakes bone dry since 2002.

But Lake Pamamaroo and Lake Wetherell last week held 531 gigalitres, significantly more than the 10 megalitres a year that the nearby community of Broken Hill needs for human use.

Alexandrina Council's Mayor, Kym McHugh, last week renewed calls for 400 gigalitres from Lake Pamamaroo and Lake Wetherell to be released to SA to save a river system he says is dying from the mouth up.

"We see that water up in the Menindee Lakes, and we know that we have to think about Broken Hill's water needs," said Mr McHugh, whose council covers Goolwa and Hindmarsh Island at the Murray mouth.

"But we think the Federal Government should be buying, or making arrangements with the NSW Government to have some of that water released down into the lower lakes."

But without direct Federal Government intervention, the water will never be seen by SA because the maximum capacity of the two lakes is held at a level low enough to keep them under NSW control.

While NSW argues it took the largest lakes out of commission because they were shallow and prone to evaporation, the Goolwa community notes it also keeps the system beyond reach of the Murray Darling Basin Commission.

The Commission can allocate Menindee Lakes water to SA and Victoria when reserves reach 640 gigalitres.

"It is an absurdity that there is a trigger level of 640GL stored in Menindee Lakes, because the current way they are operating, you are never going to make it," said SA MP Adrian Pederick, whose electorate of Hammond covers communities along the River Murray.