I first learnt about The Coorong – a narrow lagoon that runs parallel with coastal dunes for 140km in southern Australia – when I saw the 1976 film ‘Storm Boy’, the story of a boy and a Pelican.
The impression I got from the film, and then later from media reports and environmental campaigning is that the lagoon is connected to the freshwater lakes at the bottom of the Murray River, when in fact they have been separated since the 1940s by barrages – infrastructure built to keep out the Southern Ocean.
But as Susan writes in the following note, “looking at the satellite imagery of the Coorong and Lower Lakes drives home the message that the two are really part of the same ecosystem and should not have those 1940’s barrages separating them.”
There will be people disadvantaged if the barrages are now opened, in particular South Australian irrigators, and also environmental campaigners who have used images of the drying lakes to argue for more water to be taken from irrigators in New South Wales and Victoria for environmental flow.
But given the dry conditions that continue through the lower Murray Darling Basin, it is surely the best solution and would immediately restore water to this ecosystem.
Dear Jennifer
Judging from the news stories in the Australian media you would assume that all South Australians believe that more fresh water is the only solution to the predicament the communities around the Lower Lakes find themselves in.
You would read about the local group saving turtles and marching on parliament house demanding more water, the local government stating that ‘seawater is a last resort’, the environmental groups declaring a saltwater solution an environmental disaster, even the ‘Murray Futures’ a recent government/community outreach program favouring a freshwater only solution.
The website LakesNeedWater.org was launched in January 2009 when a few of us, extremely frustrated by the lack of balanced viewpoint in the media and government, decided to pool our research and make it public so that others could learn about the crisis in the Lower Lakes. We hope that if people have enough information they will come to a similar conclusion, and then have the confidence and courage to make change possible. Our goal is to have vibrant and sustainable ecosystem in the Lower Lakes, which in our opinion means returning the Lower Lakes to an estuarine system. Producing the website content is an all volunteer effort by everyone involved in the group, some of whom have never met face to face.
So when members discover information they want to share, it gets organized onto the website. We think that our new ‘photo map’ is a useful way for people to learn about the area. Looking at the satellite imagery of the Coorong and Lower Lakes drives home the message that the two are really part of the same ecosystem and should not have those 1940’s barrages separating them. We are eagerly waiting for updated satellite imagery which will more accurately reflect the current water levels.
One member recently discovered this old 2000 report from The Murray-Darling Basin Commission. That study the ‘River Murray Barrages Environmental Flows’ report recommends treating the Coorong and the Lower Lakes as one estuary, opening the barrages to the sea, and moving the barrages back to Wellington. If the government had acted then, we would not be faced with the nightmare of remediating thousand of hectares of acid sulphate soils, and a more environmentally friendly process of mixing seawater with freshwater could have been used.
If only.
Cheers, Susan
LakesNeedWater.org
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Notes and Links
The photographs were taken near Clayton South Australia from the same jetty 3 years apart – in 2006 and then in 2009. More photos are at the website.
More information on opening the barrages can be found in an article written by Jennifer Marohasy in August 2008 entitled Saving the Coorong by restoring its native state
http://www.onlineopinion.com.au/view.asp?article=7762
About the film ‘Storm Boy’ http://en.wikipedia.org/wiki/Storm_Boy_(film)
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Don’t forget that the pristine Murray in 1829 (?) was silted up when Sturt arrived at it’s mouth and the pristine Darling was too salty for man or cattle to drink when discovered by Hume and Sturt shortly beforehand.
The early settlers referred to the Darling as the salt river before irrigation began and 130 years before Cubby stn storage was ever built.
Well done, Susan, great work.
Wong’s push to get more fresh water to do the job that the tides will do for free is intellectually bankrupt. On one hand she is convinced that global warming is certain but if this is the case then sea levels will only need to rise by 40cm to render the fresh water solution unworkable.
To maintain the fresh water farce in the face of a 40cm sea level rise they will not only need to raise the barage by at least a metre, they will also need to raise all the levies around the back of the lakes, and install new ones quite a distance up the Murray River and every other minor stream that drains into the lake from the hills to the West.
So if Wong seriously believes in global warming then she is knowingly promoting a very expensive and unjust band aid solution that will eventually fail.
But if she really believes that the fresh water farce is a realistic option then she cannot take global warming seriously. In which case she is exposed as a criminal conspirator of the first order.
So what is it going to be, Penny?
“There will be people disadvantaged if the barrages are now opened, in particular South Australian irrigators,”
It is difficult for me to see how the current state of the system is in any way advantageous to irrigators.
Have we not been here before. I reckon you guys don’t give a rats about the Coorong – it’s about getting more water for irrigators. But that’s OK. Greed is good. Why not just say so?
However given all that – we also don’t want salt water going back up the Murray into domestic water intakes – so are they not building a weir at Wellington to prevent such. After all the new role for the MDB is as a drainage ditch.
“criminal conspirator of the FIRST order” – hehehe – what rhetoric…. great theatre. (BTW the 40 cm might be a while coming)
No, Luke, off topic, read the post.
But the plan to take water away water from upstram irrigators for the lower lakes is not a zero sum game. Take it from the upstream, send it about 1,000 + km downstream. Evaporation losses and “environmental flows” for the lakes, will ensure that only a small fraction, if any, of the upstream irrigators’ water will be available for the lower lakes irrigators. That plan is about reducing the sum total of water available to irrigators – for the environment.
More moronic tripe from Luke. The end of the fresh water option will merely allow the irrigators to keep the entitlements they already have. And only a green pervert like you would seriously describe keeping what you already have as “greed”.
Jan,
There is still fresh water above where this picture was taken. If the barrages are opened the salt water will flood a fair way up the system and some of those currently with fresh water will end up with salty water.
In short from a people perspective there will be some significant losers at the lower end of ths system.
I’ve been told its because all politics is local that the barrages haven’t already been opened.
So Jen, are you saying that a small pressure group can ruin things for the majority?
SJT
I’ve a few issues with the situation in the lower lakes:
1. Most Australians have no understanding of the geography and history of the region – they have an opinion based on mostly ignorance
2. There has been far too much perverse politics – adding to the misinformation
3. There has been far too much money and time wasted on non-solutions
4. Like Susan, I believe that if there was a better understanding of the situation we might start to get some more sensible political decision making
5. I favour opening the barrages for the enviornment of the lower lakes and I recognise this is going to significantly negatively impact on the property rights of some South Australians and their established water entitlements.
Actually, Jen, it is not at all certain that folks at the lower end will be adversely affected. These people can be supplied fresh water by pipeline for only a tiny fraction of the cost of the one million megalitres of fresh water that evaporates from the lake each year. At the moment they are enjoying a benefit that is being delivered by one of the most inefficient delivery methods ever devised by man.
To maintain the myth that this is a simple either/or decision is dead wrong. There need not be any losers in this reform at all.
Anyway I’ve seen the light – it’s in my business interests to keep every drop of Queensland MDB water in Queensland.
Let’s not let a drop go to southern states. Greed is good. Let’s evapotranspire it most efficiently here into fibre.
I have read stories that during the building of the barrages there were so many mulloway banked up behind the constructions, workers were spearing them with crowbars by the hundreds and taking them home to eat. The mulloway used to breed in the estuarine environment. The coorong and lower lakes are being robbed of water from both sides, the sea and the river. Opening up the barrages will only solve some of the problem. The system still needs large inflows of fresh water as well. I have read that pipelines have been built to provide towns and irrigators access to fresh water that used to rely on the lake so opening of the barrages shouldnt really be such an issue anymore. From an environmental perspective it really is a no -brainer.
Thanks Jen, I am not familiar with the geography though in two weeks I’m meeting up with a friend who is working around Australia to explore some SA national parks (to anyone from SA pointers to good places welcome) so might address some of my ignorance. However I thought acid was also a problem. Is not affecting the remaining fresh water?
In any case a weir higher up and piping might be a better solution than presently exists.
Jan,
The acid is forming where the sulfate soils are currently drying out – it will wash out when the soils are wet again creating a potential water quality problem.
one million megalitres of fresh water that evaporates from the lake each year.
isn’t the problem that if you open the barrages and build a weir and stop the input of fresh water the lake will just get saltier and saltier and die, like the coorong already has.
janama,
It was a tidal system until the 1940s, if I’m right, and survived for umpteen thousands of years as such.
We can asuume that it will revert to that same system?
Thanks Jen I guess whatever is done it will take to sort itself out but with tidal action salt water will clean it out more quickly.
Yes Jennifer, but if you build a weir at Wellington, as is proposed by the SA government, you stop the input of the diluting fresh water that was there for the thousands of years you refer to. So if you open the barges DON’T build the weir. That’s all I’m saying.
If a weir is built at Wellington, and the irrigators get their water trough pipeline, that means a savings of a million ML of water, that is not wasted by evaporation!
Assuming only this water would get past Wellington, that is still more useful water than what’s available now.
But it will be more than that, as even now water is being released, so the lower lakes will be still diluted with fresh water.
Bear in mind, that the river ran dry many times before the flow of the Murray was regulated.
Salinity levels in parts of the Coorong and Lake Albert are way above that of sea water which is only 35,000ppmv. The average depth of the lake at present is 3m and the surface is 50cm above high tide mark. So when the barrage is removed the average depth of the estuary will return to 2.5 metres.
As the tidal influence previously extended up to Morgan it will mean that the water level further downstream at Wellington will only drop at low tide. Tidal variation on full moons is about 1 metre, once each day with about 60cm on the second tide. At new moon this variation drops to about 50cm and 30cm respectively.
Under the new/original regime a full moon main tide will flush 40% of the total estuary volume (ie 1m/2.5m) each day for about a week each month. This sea water will be denser than the fresh water from up stream and will also be colder. So it will flow under the less dense and warmer fresh water from up stream. At new moon times this flushing will be less and fresh water will remain the major portion of the water column.
This is the reason why historical records refer to locals in boats claiming that fresh water always came down close to the mouth. They were tasting fresh surface water while the salty sea water extended much further in than 40% of the area of the estuary bed.
A greater volume of total sea water inflow will ensure that outflowing sea water will tend to circulate in eddies up into the Coorong and Lake Albert and thereby flush out the more saline water from these nooks and crannies.
I’ve enjoyed reading the comments, and I agree with the Jennifer’s 5 points. And while it appears that the state government is preparing for a seawater solution, much of the information that is put to the general public seems to favour a freshwater only solution. What is very worrying at this stage is ‘seawater is to be only a last resort’. Measuring when ‘last resort’ happens is a convenient moving target for the state government.
From our location near Clayton and Goolwa, it’s was pretty much ‘last resort’ about two years ago. What freshwater is left has been too saline to use for two years, and they have found areas in Currency Creek that have started producing acid this year. The state is spending millions now trucking limestone from 3 hours away to ‘remediate’ acid soils. But given the volumes needed, it is a token effort at best.
I’ve also been unable to find any information regarding tidal flows. So, Ian your comments are very interesting. We assume a larger volume of seawater would help keep the murray mouth open. If anyone has any useful links to information like that, I’d be interested in providing it on the website.
Susan is making sense. The government is providing token answers because it is expedient to do so. With the acid failure; yes just that because it is on the rise and in some places, its on the surface as sulphuric acid at almost car battery level. Light sprinkles of rain are useless; in fact this further mobilises the acid towards the surface.
As for the limestone working wonders, again its a token only. The science behind the use of lime is well known by many on the land who seek to use it to reduce a threat of acid. In reality, under the right conditions, a tonne of pyrite -rich acid soil is able to produce 1.5 tonnes of sulphuric acid. However, It takes 20kg of crushes limestone to treat a cubic meter of acid soil.Only 600 tonnes has been designated for the lower lakes system. Accordingly, this will only do an area of 3 hectares by one meter deep whereas we have an area in excess of 800sq km. Insofar as tidal flows into and out of the system when the barrages are open, our calculations presented to the government(s) show that twice daily tides, allowing for a flood level of one meter in and out will have volumes of about 800 gigalitres per tide. Officially, some engineers have reported that only between 25-30 gigalitres per day outflow will keep the mouth clear. It is not rocket science to see that the predicted volumes will play an important role in eventually clearing the mouth and keeping it that way, no less for the scouring effect and cleaning out of the channels over time, thus providing good grounds for a estuarine habitat throughout.
Yes, Susan & Ken, but keep in mind that only one tide each day is a large one of 800GL while the second one is about half that. But looking at the satellite image again, it is so obvious that such a large volume will open up the chanel considerably.
It is also my understanding that the major problem with the acid soils is the fact that levels in the lake are now below sea level and this exposes a lot more soil. Once the tides return then the depth of acid soil will only be 50cm which will substantially reduce the volume of soil at risk.
By the way Susan, you can get the tide heights from
http://tide-times.com.au/localtime_SA/Fleurieu_Peninsula/Beaches/Goolwa_Beach.html
or at http://www.bom.gov.au/cgi-bin/oceanography/tides/tide_predications.cgi
If you have the time, this would enable you to calculate the volume of each main tidal inflow (ie from low level to high) for each day and post it on your site for comparison with the fresh water option.
For example, today, Sat 30th May low tide is 0.40m at 0723 hours and high tide is 1.16m at 1630 hours for a total inflow of 0.76 metres. This 0.76 is 30.4% of total lake volume (0.76/2.5m) but the easiest way to calculate volume is to multiply the total lake area behind the barrages (in hectares) by the 0.76 metres but expressed as 7.6 megalitres/ha.
There seem to be two numbers bandied about for the area of the lake, one is 65,000ha and the other is 86,000ha. But total tidal inflow will also include the area of river surface within the tidal influence (ie, between 0.40m and 1.16m in this case). If 86,000ha is the correct number then todays maximum inflow will be 86,000ha x 7.6ml = 653,600 megalitres.
An updated and progressive table that compares daily fresh water inflows from the Murray, with augmented flows from the buy back (and adjusted for actual rather than the gross allocation), and compared with the tidal flow, would rub the noses of the fresh water advocates in the full extent of their mediocrity and the uncontestible logic of the return to natural conditions.
I was raised on Mulloway. Lets hope they all come back.
We have reached ‘the last’ resort. The weir should have been built already. The lakes contain ‘in excess’ of 500 million tonnes of acid sulfate soils. Sulphuric acid exposure is gathering momentum already but should we see increased drying out then expect an even worse situation. They are about to commence work on the regulators at the Finniss and Currency floodplains and across the Goolwa Channel at Clayton. Worst of all, they intend to then pump more fresh from an ailing Lake Alexandrina to top up the channel from Clayton, through Goolwa to the barrage. The idea being to stop further acid problems near populated areas. This will likely create the old balloon effect by robbing the lake and causing further distress upstream. Its a far better proposition to let the sea into the lower Goolwa Channel as a trial for what well may become the norm throughout the lower lakes system. For those waiting on a ‘fresh solution,’ keep in mind that, if it ever happens, then be aware that they will need to flush the whole system out and rid it of deadly acid. If it reaches that stage, then most of the barrages will be in peril because they are sitting on calcium carbonate foundations, and as it passes them, the acid will then flow straight into the recently announced Encounter Marine Park where sea life and the cockle industry will suffer.
filing this here:
http://www.abc.net.au/news/stories/2009/06/12/2597202.htm
Change of direction in lower lakes acid fight
Posted Fri Jun 12, 2009 8:25pm AEST
Pumping to end in favour of different strategy (ABC: Matthew Abraham)
A change has been announced by the South Australian Government in the environmental fight to save an area at the mouth of the Murray where prolonged drought has led to acid sulfate soils.
Pumping of water into Lake Albert from neighbouring Lake Alexandrina is to cease.
The pumping had been a part of efforts to overcome the rising acidification.
A meeting of the Murray-Darling Basin Ministerial Council in Sydney has considered a report which says it is highly unlikely the water levels can be maintained in Albert and Alexandrina due to low river flows.
SA’s River Murray Minister Karlene Maywald says a major bio-remediation program will be used instead of pumping.
She says this will include putting micro-fine limestone into the lake and planting shallow-rooted cover crops to reduce acidification risks.
“Now it’s never been done on this sort of scale before,” she said.
“It’s a very enormous area Lake Albert so we will be monitoring it extremely closely to determine whether the bio-remediation is actually successful in mitigating the acid sulfate soil and we will be ready to implement other options if we find that this is not working.”
wow its funny how myths are created but the internet gives us a new way to go about it. We wonder why terrorists come up with their own interpretation and consiracy theories about the West that results in 3000 people being killed in new York without realising that perpetuating consiracy theories is actually how it happens. This use to be done only by oral communication and be relatively limited, now because of the internet it happens at a broader scale. I’m not saying debate is not good but about the only thing I agree with here is that information should be provided openly to all so it is understood. Yes politics is a hinderance to people’s understanding because pollies want to be re-elected but what would you rather – benevolent dictatorship or a feudal system? The problem is people tend to just listen to what they want and ignore things that dont under any political system. This is something I think you would agree with Jennifer.
It is important that everyone know that the lakes were not marine since about 7000 years ago (the last ice age) when the coastal dune system that create the Coorong were formed. A range of sources show this including analysed soil cores and explorers journals. We only remember a generation or so and because water was being extracted before the 1930s drought flows resulted in a river that dried up to a series of pools and the lakes became to salty to drink. Its not that I’m saying salt water never entered the lakes, I’m just saying it is not as simple as some people think – a clear example of thus is the idiot Rann doesn’t even support the idea of the lakes always being freshwwater because he is ill informed, not having spent the time to find out the information himself.
Changing the system to a marine one rapidly now will not only affect water quality for people but is likely to wipe out the entire ecology of an INTERNATIONALLY important wetland. Letting in seawater as a long term concept and transitioning the site to a more estuarine lake system I agree is sensible – its the timeline we might differ on because of the impacts on the place and its people (not forgetting the Ngarrindjerri) but also because introducing seawater into an acid sulfate soils affected previously freshwater wetland might exacerbate acidification not improve it. If you spend the time to read the information about other sites in Australia affected by this issue you will find it is both very different but also saline water causes pH to drop not stabilise or increase by preventing oxidation of the sulfides in freshwater lakes.
Lastly The restricted mouth and more importantly narrow channels that connect the Southern Ocean to the Lake via the mouth and Coorong will mean that the tidal signature is significantly reduced. If people took the time to read the information that is out there on the sand pumping (dredging) project they would see that opening the barrages and expecting the tide to maintain the mouth and sufficiently flush the system are wrong. I know it sounds stupid but read the reports and then tell me I’m wrong. The present EIS that SA now has to put together will summarise this and help all of us to understand the facts better (hopefully).
This action of “re-connecting the Coorong” unless planned properly will just result in the lakes becoming a hypersaline, acidic wasteland that will cost significantly more to re habilitate
Sebastian
Sebastian, if you opened the barrages this estuary would revert to its essential being. The healing would begin.
Hugoagogo, if you open the barrages this ‘estuary’ would not revert to its essential being unless that is a salt lake – it would revert to a hypersaline,acidic wasteland because the tidal volume moving in an out is too small – the lakes would essentially act as a salt pump due to evaporation in the lakes being greater than the inflows from upstream and only more salt coming in from the sea through a constricted mouth top replace the evaporated water.
Look at the tidal levels at the Goolwa Barrage as opposed to Victor Harbour and see how different they are – this is the tidal ratio and the information available in reports on dredging the mouth show you the ratio is very small – insufficient to allow water movement in and out of the lakes to make it an estuary – it would quickly become similar to the South Lagoon, just on a larger scale with a fresh bit at the top.
This place is so different to estuaries in NSW I cant go on to explain that in enough detail here but if you look at the info about Trinity Bay (I think it is) you see how it should work. Because of the restricted mouth, the system does not work that way and instead you end up with a hypersaline inlet and you dont get additional alkalinity generated so it will probably just end up hypersaline and acidic.
Instead of us just assuming what we want it to be, please spend the time to read the information that is out there and bring it together to have an informed debate. The DEH (SA) website has lots of info and so does the MDBA/MDBC and DWLBC websites…
Comment from Ken, July 5th 2009 at 5-35 pm
By turning the system back to what it was pre-barrages will rectify a massive problem confronting the lower Lakes and Goolwa Channel.
The greatest mistake was to build the barrages in the first place. Sadly back in those days our understanding of putting barriers in front of nature wasn’t fully understood.
Should our current managers of the lower lakes resources have been approached with a a similar proposal today, then it wouldn’t make it past the first base.
The barrages would be tossed out of the equation because of the enormous environmental impact and the lakes as storage would be doomed to failure as they are too shallow in relation to the very large surface area where evaporation loss is far too high. In recent consecutive years, the evaporation rate from Lake Alexandrina has been more than what the river holds between Wellington and the north -eastern border. With a national water failure through drought and overuse, we cannot and should not waste a drop in the lower lakes. Backtracking the lakes to become estuarine again will give nature back what it had before. The evidence of a previous lakes estuary is bountiful. Just the samphire alone has survived to tell the story.
May I suggest that you check Under Letters in “lakesneed water.org further details on this crisis.
Ken
Ken
Thanks mate – I’ve been there and checked it out and I think it would be useful for you guys to check out the info on the situation in QLD and Northern NSW and what has happened there and the differences between there and the Lower Lakes – the logic put forward here and in some of those letters doesn’t stack up.
I stick by the last paragraph of my previous post and add a few links to check out for your info
http://www.nrw.qld.gov.au/land/ass/ – simple easy to explain info on coastal ASS (different to our problem here where it is a freshwater lake)
http://cat.inist.fr/?aModele=afficheN&cpsidt=16632997 (scientific journal paper outlining how the Trinity Bay problem has been managed in a similar way to what you are proposing and what impacts that had regardless – worth noting my points about tidal flux would mean the tidal flushing here needed to make it work wont occur)
Sebastian
Dear Sebastian,
I think you are hitting the nail on the head when you are saying that it is unlikely that by simply opening the barrages the Lower Lakes will revert to a healthy estuarine system. My reason for this is covered by an article from D. J.Walker who talks about the hydro-dynamics of the Murray Mouth. The key feature is that the effective head of the Southern Ocean is about 500 mm above that of the sea, because of the strong Southern Ocean swells and the wind action of waves pushing sand up through the channel to produce a spring tide delta.
The only way to overcome this is to have a pressure head on the landward side that can overcome the net forces of the tide + wind + swell action. Nature has done this over the millennia by periodically flooding the river system and it is those times when the shape has been sculpted. Between these flood times, the tidal action as you say has its effect but over time without the strong force of flushing by a flood, the mouth would close over.
Have a look at what happened on the Glenelg River this year = the mouth closed over and the river flooded the town of Nelson before the river managed to burst through and re-open the channel to the sea. This is what had happened in the Lower Lakes and Coorong for thousands of years and would go on doing so but for mankind taking away the floods and building barrages to alter natural cycles.
I agree totally with you that by merely opening the gates will not make any long term difference and that is why I dreamt up my solution published on the above page. Please read about it and let me know what you think. It is a heavy engineering solution I must admit, but it may just work because it recognises the operational dynamics and has elements that deliver on the parameters required to kick start this moribund environment again.
Hoping for increased inflows from upstream is a bit of wishful thinking. Government action is proving to be impotent at doing anything in this regard and it is high time we accept the mess we are in and make something good out of it all.
Sebastian,
The Lakes are no longer required construction of the new pipelines with filtered water from Tailem Bend to properties in the Lakes district and Langhorne Creek connected to Strathalbyn supplied from Murray Bridge. The irrigators will have their seperate pipeline via Jervois, Langhorne Creek and Currency Creek completed by October, 2009. The reliance on the Lower Lakes for water being transferred upstream ( doesn’t that sound familiar ) to Tailem Bend with the exception of Point Sturt and Hindmarsh Island. The Government has been forced to rectify this matter of segregating them from the rest of the Lakes community and will now supply them with filtered water. You mention the Ngarrindjerri people, they and European settlers both have help change the Lakes. In 1888 Point McLeay Aboriginal Mission requested a grant of 500 pound to set up an irrigation scheme to enable root cops to be grown. Mr Taplin explained that they wanted equipment to pump 30,000 gallons per hour from the after raising it thirty feet. He sais “the water in the Lake was eminently suited for the purposes. In S.A. it has taken from 1885 until 1938 to turn the Lakes into a salt and sea water cocktail. 1940 the arificial Lakes were created by building barrages and in the meantime a RAMSAR agreement has been signed. I wonder if signing that agreemnet was a lever to get a guaranteed water supply of 1850 GL per year for S.A.
Peter above has explained to me how just opening the barrage will not work and that water will have to be pumped into the system over the Tauwitchere barrage into the Lakes as he says go back to Letters “Retoration with vision” click on the link.