JO NOVA has posted on the Murray and Media Watch with comment:
“She [Jennifer Marohasy] wants to restore the estuary to its estuarine (salty) form. The end of Australia’s biggest river (the Murray) has barrages across it, to stop the salt water entering. The farmers near the end now depend on the freshwater, just as the farmers in the middle of the long river depend on the highly variable water there too. This is a big policy dog-fight I’m not in on. But I suspect if someone were suggesting putting barrages across the Yarra, the Swan or the Brisbane, the Greens and the ABC would not be attacking people who opposed the barrages. There is no higher principle or policy sense at work here.”
Read more here:
http://joannenova.com.au/2012/03/jennifer-marohasy-and-abcs-mediawatch-tribal-warfare/
Charles Bourbaki made comment in the thread:
“Australia is one of those rare countries where the twice daily tidal influx has no influence on our estuarine rivers. Saltwater crocodiles are never seen in them and people are safe swimming many miles inland. The scientists at Media Watch know this and are quite rightly asking questions.”
I’m so used to having to defend my position and explain that there would be tidal inflows without the barrages that I didn’t get the sarcasm and left comment suggesting I have absolutely no sense of humour.
Thanks Jo and Charles for helping to get some much-needed perspective back into this issue – at least for me.
And the following letter sent into the Victor Harbour Times (a newspaper read by Lake Alexandrina residents) last autumn provides a very local perspective:
Sky High Salinity & SA Water
Tuesday, 31 May 2011
Re the statements by SA [South Australia] Water spokesperson published last week in the Times.
He started absolutely spot on with “The barrages are designed to protect water quality in the River Murray & Lower Lakes by providing a physical barrier between the fresh water in the Lower lakes & the saline water in the Coorong.”
This is exactly what SA Water is failing to do. They are maintaining too low a level upstream of the barrages. Currently levels US Goolwa barrage are fluctuating on the tide (Tuesday 31st between .28 metre & .54m). When a high tide and southerly wind arrive, like the .77m of the 24th May we have massive entry of saltwater. This is not a minor “some salt water entry”. Neat salt water reached as far as midway between Point McLeay and Point Sturt. There is large loss of freshwater dependent aquatic life along with loss of water by irrigators who receive no warning. Hope everyones auto watering systems for stock & irrigation were off.
It is not all flushed out in the following days. A week later we have salinity from 2,8000 at Clayton to 2,000 at Goolwa. Currency Creek went to almost 10,000 at the peak and will probably take months to come back down with the regulator limiting the flow.
There should no longer be a large number of gates open, flows are now down to 24,00Ml/day from some 80.000 at the end of February this year.
Two thirds of the gates should be closed with a level maintained around .5 – .6m.
Lets hope when they do eventually close the gates they have fixed the barrages, to prevent the saltwater leakage experienced last year. Have any capital works been done? Perhaps it’s not too late for maybe rubber strips between the joints in the logs.
The barrages needs to be managed to do what they were built for so as to benefit the Lakes community rather minimise SA Water’s costs & manpower requirement.
Ideally the level should be raised as much as possible to maxmise the flow into Lake Albert, Currency Creek and other salty wetlands. When all full level should be lowered to a safe level depending on sea tides and wind forecast. This cycle is then repeated in order to get maximum freshwater exchange into these areas.
Thanks
George Bennett
PS Sunday evening looks a fair chance for another good dose of saltwater.
******
Thanks to CJ for finding the newspaper clipping for me… again.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Jen, do you have any data for how far salt water actually travelled upstream as a result of dry conditions in the MDB?
I know that undrinkable, salt water was found near Bourke by early explorers but was that sea salt or generated from the local salt table during a drought?
Spangled
Sea water didn’t get up as far as Bourke during modern times. But it did probably extend as far up as Morgan which is about 270 kms from the sea mouth of the Murray River. See my chart 2 at this link: http://www.mythandthemurray.org/wp-content/uploads/2011/09/A-Note-on-Murray-River-Salinity-Levels2.pdf
The chart is part of a ‘note’ I put together for Water Minister Burke after I met with him in Canberra last year… Because his staff appeared to have no idea about salinity levels in the Lower Murray. I never got any acknowledgement back from the Minister office regarding the briefing note with data on salinity.
Stay strong Jennifer, we all lose our perspective in times of stress. I think it was no coincidence that Media Watch were “watching” you at a similar time to the release of the cherried-picked details and unsubstantiated impacts contained in the BOM & CSIRO’s State of Climate Report. Combined with the ABC’s overuse of the word “unprecedented” when describing the Riverina floods (Wagga suffered a worse fate in the mid-50s “Big Wet”) we have what were once three great Australian institutions that can no longer be trusted as to whether or not they are obfuscating with the general public. In other words there appears to be a lack of due diligence on the part of these institutions’ public utterances that may leave them open to legal challenges.
Perhaps if there are any fair-minded people working for Media Watch they can report on the appropriateness of the ABC’s use of the word “unprecedented” when describing the recent floods!
Worth reading in the context of the “bigger MDB plan” picture: http://wattsupwiththat.com/2012/03/12/i-wonder-if-gleick-is-invited/
Climate change (aka CAGW, uses carbon fears to control energy and other production, transportation, etc), water (in Australia’s case, the MDB plan for example, using notions of “food security” to control, and sell, water rights), and multi-purpose land use activities (outlined by the UN’s Agenda 21) are the three pillars upon which the notion of sustainability lies, itself a “cover” for all encompassing and globally wide environmental laws that were, in part, to be implemented by the 15th Conference of the Parties (COP) to the United Nations Climate Change Conference in Copenhagen, 2009.
This Jennifer, I think, is what you are fighting and perhaps why you were singled out by Media Watch. Their “noble cause” is built on very shaky ground and it will only take a few brave “Davids” to stone this “Goliath” into submission. Behind the scenes though the CAGW retreat is on (thanks in no small measure to the Climategate emails and the Harry Readme file) – attention is now focused on water and water security as the next big “scare” in this Hegellian charade.
Hi Spangled,
There’s a story that is part of the folk lore around the Lower Lakes area that ‘there was a sighting of a dolphin at Murray Bridge’… Doing a bit of research around that, I found the following stories. The years of these sightings correspond to what the old timers called ‘low river’ or drought years.
http://lakesneedwater.blogspot.com.au/2011/11/dolphin-at-tailem-bend.html
There’s even an old photo of locals near the ‘porpoise’.
Susan, How far are Tailem Bend and Murray Bridge from the sea mouth of the Murray?
Jennifer
I’m Looking at the map now, Wellington is about 8Ks from the river entering the lakes
Tailem Bend is about 35 K and Murray Bridge is maybe 70 K give or take.
That is from the point of entry to the lakes, if you take a straight line then you have to add an other 70 Ks to the shoreline/mouth.
Can’t see any problem with a dolphin getting up that far, maybe further, who knows?
I mean some of us are talking in recent times and others in geological times.
There is the difference.
Hey Mark A
Thanks for that, and I see the caption reads:
“… saltwater could reach as far upstream as 250 kilometres from the Murray Mouth, and river levels could fluctuate considerably.
In 1926, two porpoises were found to be living in the salty water around the Tailem Bend area. The porpoises lived there for several months, until the freshwater returned. One of them died at Tailem Bend before it was able to return to the sea. It was common to refer to the creatures as ‘porpoises’, but it is now thought that they could have been a variety of pygmy whale.”
It would now be physically impossible for pygmy whales to enter Lake Alexandrina.
Remove the barrages – tear down that wall – bring back the tide.
Here’s a google map of the area:
http://www.lakesneedwater.org/maps/river-murray-barrages-and-lower-lakes-south-australia
As a crow flies, (or a dolphin used to swim) from about the Murray Mouth to Tailem Bend is about 60km (according to the Google mapping tool).
It is 274 km from the Murray Barrages to the next lock named ‘Lock One’ at Blanchetown. So the entire body of water from Blanchetown all the way to the Barrages near the mouth are controlled as one.
Thanks Jen and Susan. Been away today. I can’t imagine the following was due to sea water but I do seem to remember reading of one explorer finding salt water near the junction of the Murray and the Darling;
Charles Sturt:
Darling River near Bourke 1828 –
“The trees that overhung it (the river) were of beautiful and gigantic growth. Its banks were too precipitous to allow of our watering the cattle, but the men eagerly descended to quench their thirst……..nor shall I ever forget the cry of amazement that followed their doing so, or the looks of terror and disappointment with which they called out to inform me that the water was so salt as to be unfit to drink! This was, indeed, too true: on tasting it I found it extremely nauseous”.
What I meant to add above is: has this salt water phenomena ever re-occurred in the upper reaches of the MDB for ANY reason?
IOW, does this salt water phenomena occur due to reasons other than sea incursion?
Saline springs on the Darling (I think they also occur well upstream of the Murray junction) undoubtedly result from the incursion of salty groundwater, not sea water.
Hi spangled drongo,
Whiting have been caught as far upstream as Younghusband but no one even within SA Water can tell me the exact spot the bottom of the River Murray begins to rise above sea level!
Hi Susan,
Seawater fish have been caught at Younghusband 166-Km’s from the Barrages.
Hi Jennifer,
From the mouth/Barrages Wellington 76K’s, Murray Bridge 112K’s, Mannum 150 K’s, Younghusband 166 K’s, Swan Reach 246 K’s, Blanchetown/Lock 1 274 K’s.
Thanks for the information Peter. When where the whiting caught at Younghusband? What years by whom?
Thanks Mark and Peter.
Interesting point about river bed and SL, Peter. The local SA surveys office should have that data. If not precisely that, at least relative levels of various upstream lowland areas and depth of channel in those areas so that subtracting depth from RL should give you an idea.
SD
“The local SA surveys office should have that data. ”
We know for certain that the fall in level for the last 160 Km of the river is 2.5 cm (25mm)/Km
if you know the level where the river enters the lake you can work out how far the highest tide would travel.
The overall fall of the river is only about 115 m not a lot for the length, not including the top of the mountain ranges of course.
But as you said the SA surveyors are very well aware of it all.
Thanks Mark. That would probably put Younghusband river bed at around mean sea level.
A little further west it actually slopes the other way and Lake Eyre as we all know is below SL.
Might help to understand the levels:
http://www.rmboa.org.au/river_levels.html
Looks like the last 250K is flat as a pancake and it only needed a higher than usual tide coupled with a good wind behind it for sea water to travel a fair way upstream.
Hi Jennifer,
From memory Ken told me that about 10 or 11 years but he is over ninety now and would not any longer be able to hold a worthwhile conversation.
From memory it would have been between 1915 and 1920.
Hi spangled,
I am seeking that information and have a meeting with the Minister tomorrow so will follow up on that!
I believe that sea level if further upstream of Younghusband and have been seeking the correct information for some years.
Hi Jennifer,
I just realise my dates are out it must have been (as I believe he said he was about 12 or 13-years of age) the early 1930’s.