I know the dams at the top of the Murray River are very low, but there is still water in the lower reaches of the system.
Today I visited the so-called Murray Mouth which is part of the Coorong National Park.
We then drove around the western perimeter of the huge estaurine lake system.
While the national consensus appears to be that some sort of catastrophe is about to befall this region -- interestingly there are new housing developments and new olive orchards and more...
Crossed the ferry at Wellington - what I think is the real Murray mouth.
And there was also water in the river a bit upstream of Wellington.
I'll be back in Brisbane tomorrow. And many thanks to Phil Sawyer for a great few days in South Australia.
My mistake, the river does or did indeed flow into the Indian Ocean. I’m not sure how that can be but as feelings of patriotism now flood over me, I think we should mount a campaign to claim this slice of sea Australian.
Rojo.
A few weeks, ago after heavy rains the lake seemed to have been replenished, a huge expanse of water had inundated mudflats after only just a couple of days of rain, I was amazed! Two days later the water was gone, and no evidence of the wet weather remained.
It had not been hot, so my first thought that evaporation had dried it up was wrong, it turned out that the water, no more than an enormous surface puddle, had just blown away in the wind.
The palaeontologist report is incorrect on so many levels so it’s hard to pick just one thing that might make you think again. However thankfully the authors actually locate the mouth of the Murray on the Indian Ocean, so there’s an easy place to begin ripping it apart; This geographical clanger might also give you good cause to doubt the executive summery and some indication that you should also question the study as it establishes the ancient salinity levels from just core samples alone.
Subterranean Water tables in the area are inundated by sea water which rises through the sand; this would interfere with any salinity levels in the core samples taken and make any conclusion unreliable.
The main study actually indicates that the Murray had an enormous effect on the system although in the executive summery this conclusion is reversed.
Therefore we must rely on common sense instead.
Before settlement Lake Alexandrina was tidal and a hundred years ago a barrage was put in place primarily to keep salt water from entering the lake. Before the barrage the system had the possibility of benefiting from partial flushing as the tides came and went.
This situation allowed river water to flow through the mouth at low tide and mix with incoming sea water lowering salinity levels at high tide when the tide carried a mix of water into the southern end of the lake.
The systems salinity was also diluted by the interaction from local catchments as rains added more fresh water to the dune system, so we should not presume that the river is the only source of fresh water.
In conclusion the systems salinity levels depends very much on the location from where tests are taken as flows through either the mouth, lake or local catchments determine water levels within still or stagnant sections of the system.
If water levels remain low salinity levels will remain too high throughout for the ecosystem to survive
There are only two sources of energy that power the system, the Southern Ocean and the river. These two sources of power deliver interaction of fresh and salt waters that has been undermined by human action.
For three decades between 1960 and 1990 South Australia recorded good rainfalls when much of the agriculture along the Murray was established. During this time environmental flows were only just enough to maintain life support system from the lake to the sea,15-20%. However since 1990 rainfalls across Australia have declined while a demand for water has increased. During this time policy makers have shown no effort to protect the environment. In fact the policy has been to ignore the problem until the system suffers complete collapse, which can now be guaranteed.
Simon, yes it is a lake with an average depth of 3m and yes it has mudflats just like it always had. You stated "it is now a mud flat" when there have always been mud flats, some 16000ha of them. They even call them wetlands.
The lakes pre european settlement could not dry out completely as the tide would flow in to replace water lost to evaporation. So no, the saltpan isn't obvious.
"Once able to supply fresh water into the Coorong, making the sea water brackish, Lake Alexandrina is now too shallow and too salty to effectively maintain the ecosystems balance."
Perhaps you could have a read of the study I linked and tell me if you still think the same.
How much shallower do you think the lake is?
sorry couldn't detect the sarcasm, had a look back and still can't.
I used an incorrect number for the MDB area, so you are closer to the mark than I thought. My apologies.