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September 2, 2008
Pia Ackerman in The Australian reports that the acid sulphate soils, which threaten the Murray's lower lakes in South Australia, have spread to the river system's northern catchments in Queensland where up to 200 sites are under investigation by scientists. Pockets of acidification are also emerging in northern Victoria and along the Murray River in southwestern NSW. Acid sulphate soils can occur when river and lake beds are exposed to the air as water levels fall, triggering a toxic chemical reaction.
The Murray-Darling Basin Commission ordered the investigation in southern Queensland amid mounting evidence that wetlands and rivers in the north of the system were succumbing to the poisoning that threatened to overwhelm. More than 12,000 wetlands are potentially at risk in Queensland alone.
This is yet another sign of the consequences of taking too much water from the rivers by irrigators. Not that much will be done by Rudd and Wong to address the situation, judging by the way they handled the situation in the lower Lakes. It was a too little too late style of management in buying back over-allocated water licences.
The situation in the lower lakes is that unless it rains heavily between now and summer, October 28 may be the date used on the headstone of the Coorong and Lakes as it is laid to rest as a significant wetland. The Coorong will be delisted as a Ramsar wetland and become equivalent to the Dead Sea.
I doubt that Rudd or Wong will attend the wake. They will say something about climate change rather than mismanagement, do little to buy back irrigator licences, and allow the states to continue to grab as much as they can get for their irrigators.
Update: 3 September
The submission released by Senator Wong, to a parliamentary (Senate) inquiry into the Murray emergency, detailed eight emergency measures under consideration to prevent Lake Alexandrina and Lake Albert near the river mouth from turning acidic. But the advice from the Department of Environment, Water Heritage and the Arts makes clear that there may be little option but to flood the lakes, southeast of Adelaide, with sea water.
Diverting more water from the key southwestern NSW reservoir of Menindee Lakes could jeopardise drinking water supplies for downstream communities, including Adelaide, in 2009-10. Releasing water from Menindee Lakes would be taking water that may be needed for human consumption in the 2009-10 water year if rainfall remains low across the basin. Up to 50 per cent of any release from Menindee would be lost in transmission.
There is not enough water in the system to meet the modest allocations promised to farmers in the past two months and supply water for Adelaide and the towns along the Murray. Wong's priority is securing Adelaide's water supply and the towns along the Murray until next winter. There is no water for the lower lakes.
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Why would returning the lower lakes and Coorong to their natural estuarine state lead to the first being "laid to rest" and delisting of the latter?
To quote from Charles Sturt's "Expedition down the Morumbidgee and Murray rivers, in 1829, 1830 and 1831", vol.2, chapter 6, reporting on his second day on Lake Alexandrina having left the "termination" (i.e. mouth - just a little below where Wellington now stands) of the Murray the afternoon before:
"Thus far, the waters of the lake had continued sweet; but on filling a can when we were abreast of this point, it was found that they were quite unpalatable, to say the least of them. The transition from fresh to salt water was almost immediate,"
A little further he notes: "The flat we were approaching was a mud-flat, and, from its appearance, the tide was certainly at the ebb. We observed some cradles, or wicker frames, placed far below high water-mark," http://ebooks.adelaide.edu.au/s/sturt/charles/s93t/v2ch6.html
Before the barrages were closed in 1940 bream and mulloway were regularly caught at Murray Bridge and dolphins sighted as far up river as Mannum (BTW-without the barrages the water level there would be at least a metre lower and subject to tidal influence).
The constant whining about "saving" the lower Murray is driven by economics, not environmental considerations. The river, lakes and Coorong are only in danger if vested interests succeed in delaying a return to the natural state.
As your article should be making clear, any spare water would be of far greater benefit in the upper reaches of the Murray, and in the Darling.
If the acid sulphate soils there begin leaching toxic chemicals into the rivers in any quantity then the state of the lower river is immaterial. All the communities along the river, plus Adelaide and Whyalla will be stuffed anyway.