By Trevor Harden, Clayton Bay
The Lower Lakes crisis – an objective analysis
An environmental and human disaster is happening before our eyes – the Lower Lakes are drying up. A lake without water is not a lake – and a dry wetland is just that – dry – its environmental value lost.
So, what can be done to minimise the harm?
The Issues
There is universal agreement that a mismanaged and over-allocated irrigation diversion regime upstream must be fixed and when catchment inflows return to ‘normal’ after the drought this will be the ongoing issue – but the Lower Lakes disaster is happening right now.
If we consider the options and the sub-issues they generate, some of these ‘options’ will be seen already to be impossible.
There are no longer any win/win solutions and any action taken (or not taken) will have a downside and involve a balance between competing needs - difficult times for governments who will be blamed by the ignorant (and the Opposition) for the downsides, even if the outcome is the best possible net result.
Blame is already a significant part of community feeling about what is happening but blame can’t make it rain nor can it minimise the harm – right now.
Freshwater, Seawater or No water? – this is the fundamental issue to be resolved and resolved soon, to salvage what can be saved from this environmental and human disaster.
Let’s consider each of these alternatives in turn.
Freshwater?
In many ways this is not an issue of dispute in that everyone would prefer there to be a freshwater solution to the Lower lakes crisis – State and Federal governments included.
What has become a major point of contention is whether this solution is possible in these times of consecutive record low inflows to the catchment. The River, Lakes and Coorong Action Group have claimed that the freshwater solution is available and that the State and Federal governments are to blame for not making it happen.
With continual reference to the dire situation in the Lakes (which is not in dispute), the value of the wetlands (which is not in dispute), the environmental consequences (which are not in dispute), the historic mismanagement and over allocation of irrigation water diversions upstream (which is not in dispute) and then stating (against the scientific evidence) that the water is available upstream and that it could be got here in time – they have generated a following of those who are more than willing to blame State and Federal governments for the problem.
And having someone to blame is a compelling psychological need for many people when they are anxious and hurting.
And of course Opposition politicians have a vested interest in making life difficult for governments. What a pity that a natural disaster of this magnitude can’t be addressed on the basis of the best scientific and practical advice and be given bipartisan support. Political agendas and obstruction will inevitably risk and/or delay important responses to this crisis and be detrimental to the same human and environmental needs which the Action Group claims to be fighting for.
The lakes are very large and to raise water levels by one centimetre requires up to 8 GL and yet, in the middle of an early February heatwave with over 6 GL evaporating every day we have a prominent politician claiming that, “The Lower Lakes need about 20 GL to get through the summer”, and bagging the government for not making it available.
Politicians who understand the reality and the expert advice being given to governments about necessary action but who seek to gain some perceived political advantage by supporting those who oppose that action are being highly irresponsible in these times of crisis. Similarly, treatment of the issue by print and electronic media often promotes ignorance of the facts in the pursuit of a ‘story’ and is equally irresponsible.
To accept the propositions of the anti government activists we have to accept that either the scientists and professional employees of the CSIRO and Murray Darling Basin Commission have been incompetent and/or dishonest (and why would they be?) or that State and Federal governments have not been doing their best to manage a very difficult environmental and human crisis (and why wouldn’t they?).
Activists and their followers are angry about the Lower Lakes and they are angry at Rann, Rudd, Maywald and Wong but we need to be clear just what it is they are angry about and whether the evidence justifies that anger and its targets.
Most of what they are saying about the value of the Lower Lakes and Coorong wetlands is not in contention – it all comes back to whether there really is water available, enough water to make a lasting difference to the Lakes, that is being withheld (for some reason??) by the State and Federal governments.
If there is no such water available (and catchment inflow data suggests there isn’t) and the scientists and government advisors are right – then the whole ‘local activist position’ is untenable.
If a freshwater solution is not possible the only alternatives are ‘Sea Water’ and ‘No Water’
The ‘No Water’ Option?
The effects of ‘no water’ on the Lower Lakes are already evident with water levels falling more than 1.5 metres below the ‘normal’ freshwater pool level and leaving exposed large windblown expanses of potentially acidic sand and mud. This is happening right now.
The scientific advice to governments has focussed upon the permanently destructive effects of acidification as acid sulphate soils exposed to air become highly acidic and produce sulphuric acid when wet (by either rain or rising water levels). These high levels of acid would leave the Lakes ecologically sterile into the foreseeable future despite the return of freshwater – the Lakes would then truly be dead.
The ongoing hope for the past two years has been that the drought would end and that catchment inflows would be sufficient to make planned actions unnecessary but record low inflows have continued – and Lake shore-lines have continued to recede. To enable forward planning of ‘harm minimisation’ strategies, on the advice of their scientists and expert advisors, governments have set arbitrary ‘trigger’ points as indicators of minimum lead times to enable timely action – temporary weirs cannot be built overnight.
While the current government focus is on avoiding irreversible acidification; salinity and dessication (drying out) are also serious environmental issues. Salinity levels are increasing with the whole Goolwa/Finniss channel now one third the salinity of seawater (and more than half near Goolwa). It is no longer a freshwater environment and the water has been unsuitable for human use for a long time.
SA Government advice is that under ‘worst case’ evaporation conditions this summer, acidification ‘triggers’ wont be reached until early 2010 and may be delayed further (or even indefinitely) with strong winter inflows to the catchment. They have initiated the approval process for seawater to be used to keep levels above critical acidification levels - provoking loud protests from the ‘freshwater only’ activists who have interpreted Federal Environment Minister Garrett’s requirement for an Environmental Impact investigation as some sort of success.
But have the scientific advisors fully anticipated the problems posed already by dessication?
Corrosive Dust-storms are being kicked up from the exposed flats by anything more than a light breeze – and these are very windy places. And as the levels continue to fall this will get much, much worse.
It is possible that hundreds of thousands of tonnes of dry sand moving across the Lake beds to build up along shore lines (and the very fact of wetlands drying up), are of themselves environmental disasters at least as problematic as the feared acidification. The intrusion of fine corrosive windblown sand into human habitation along the shores of the lake will cause untold damage – and it is happening now.
One thing we can be sure about is that water levels this low are totally unprecedented over the thousands of years of natural conditions prior to settlement. If severe droughts ever reduced flows to current levels (and in all likelihood they did), seawater would have moved in to maintain the lakes at sea level – it is only the man made intervention of the barrages that is preventing this from happening now.
Those who are advocating the totally impracticable chemical treatment and/or bio-remediation (planting of reeds etc) of the tens of thousands of hectares of lake bed which will be exposed by next summer are not facing reality – the Lakes need water now!
The freshwater of an ideal world is not available – which leaves seawater.
Seawater?
One high profile antigovernment activist has been quoted as saying that letting seawater into the Lower Lakes would be “like an atomic bomb” and would kill everything. He says the lakes have always been fresh, “and we can prove it”.
And people are concerned that once salt water comes in it will be there forever.
But how valid are these statements and concerns?
Certainly an estuarine mix or a full seawater marine wetland environment would mean major changes to the ecosystems that were there before the drought – but salinity is changing that now – where there is water. And where there is no longer water – the aquatic ecosystem is already dead. A living marine ecosystem on the other hand would have value in its own right – it would be different but not dead.
Logic suggests that if strong freshwater flows return to the system after the drought they will inevitably replace salt water with fresh – no problem - and if strong flows don’t return then a marine system is inevitable anyway and might as well be established sooner rather than later – with the added benefits of preventing acidification and stabilising the windblown sand.
But if the Lower Lakes were never salt water over the thousands of years before European settlement, that in itself would be a good reason not to let it happen now. Of course neither did they ever dry up during those thousands of years and that is a very good reason not to let that happen now. There are choices to be made – and value judgements.
But while we can be sure that the lakes didn’t dry up over recent geological time – gravity and sea levels ensured that couldn’t happen – how sure can we be of the claims that the Lakes have always been fresh and never salt?
The ‘research’ most often referred to by members of the River, Lakes and Coorong Action Group, in support of this claim, is the document, “A Fresh History of the Lakes: Wellington to the Murray Mouth, 1800s to 1935” by Terry Sim and Kerri Muller and published by the ‘River Murray Catchment Water Management Board’ in conjunction with the ‘Goolwa to Wellington Local Action Planning Board Inc’.
This ‘historical’ research is a collection of excerpts from “newspapers, Parliamentary debates, diaries, journals, reports, letters and family and local histories and surveyor’s notes” which shows very clearly that the upstream extraction of water for irrigation purposes has been a source of great contention since the 1880’s with low flows at the mouth in times of drought attributed to these diversions.
The document also indicates that the lakes were likely to have predominately fresh for extended periods over pre European times – (which is not in contention). What it does not prove, however, is that the Lakes were always fresh, even in times of severe drought. The credibility of this ‘research’ is significantly reduced by clear evidence of bias in the selection of data for inclusion. At least some data used to make a case for the Lakes having been exclusively fresh would have suggested the opposite conclusion if the full story was considered. You don’t prove anything by searching for examples to support a preconceived conclusion and rejecting data that doesn’t fit.
On the other hand, scientific research into core samples of the sediment laid down in the bed of the Lakes over thousands of years ( Professor Peter Gell - include referenceXXX) show conclusively that the Lakes, as might be expected, have been salt at various times over the past 6000 years – a typical estuarine characteristic of river mouths across the planet.
And so, if the only alternative to allowing seawater through the barrages to raise lake water levels is to allow levels to continue to fall, soils to acidify, wetland ecosystems to dry out and die and windblown corrosive sandstorms to create destructive havoc around the shores – there is surely no question as to what should be done – sea water must be allowed to return the lakes to sea level until such time as freshwater flows can restore pre drought conditions. – and sooner rather than later.
When?
The windblown sand problem is already here and will get worse very rapidly as summer evaporation continues – another few centimetres of loss will see the Finniss estuary disconnected from the Goolwa Channel and shortly after that the Goolwa Channel itself will disconnect from Lake Alexandrina east of Clayton Bay – creating a land bridge from the mainland across to Hindmarsh Island.
BUT - the government’s current advice is that seawater won’t be needed until early 2010. The ‘last resort’ temporary weir at Wellington as part of the package, preventing sea water from contaminating the lower reaches of the river and protecting water supplies for Adelaide’s ‘critical needs’, country towns and Lower Murray irrigators.
It is possible also that the Environmental Impact process for seawater intrusion will require the ‘fresh’ water wetlands of the Finniss and Currency Creek estuaries to be isolated from the seawater with temporary barriers.
Current government plans to create an artificial pool level between Clayton Bay and Goolwa very soon, to be sustained by freshwater winter flows from those tributaries, would serve this purpose along with several others (including Goolwa’s commercial tourist industry) and would deal with the sandstorm issue at least for that portion of the system. Lake Albert levels have been prevented from falling further by a barrier at The Narrows and continuous pumping. But what of Lake Alexandrina? – with vast exposed expanses of windblown sand already on the move and getting rapidly worse as the levels drop.
Raised water levels are urgently needed. Huge environmental and human damage will have already been done well before early 2010 which is currently the earliest planned seawater entry – and then intended only to the level needed to reduce the most serious acidification – the windswept sand flats will still be there. And daily corrosive dust storms will continue. And the ‘world heritage’ wetlands will not only be saline – but dry.
Questions?
What if seawater was allowed in sooner? – say as soon as the planned Finniss and Currency Creek pools are isolated?
What are the cost/benefit balances to be achieved?
Could it be done before the Wellington Weir is built without compromising the quality of Lower Murray water?
Would the head of pressure produced by raised Lake levels be sufficient to keep freshwater flows in the lower reaches of the river at raised levels without saltwater moving into the river?
Would there be sufficient freshwater flowing from the Murray into the Lakes to prevent salt water flowing upstream?
The Wellington Weir – was it ever an ‘environmental’ issue – really?
The River, Lakes and Coorong Action Group was formed in late 2006 in response to the proposal for a temporary, low level weir to be built at Wellington as a last resort to protect critical human need water supplies to Adelaide and country South Australia. The group chose to reject the Government’s explanation and rationale and promoted the proposal as an environmental disaster about to be imposed upon the Lower Lakes by the State Labor Government – their slogan of “Stop Rann’s Weir’ was overtly political, (and they continue to oppose government responses to the crisis).
Attempts to explain that the Wellington weir would not cause the Lakes to deteriorate but rather would be in response to that deterioration, (if it occurred due to the drought), fell on deaf ears. It appeared that this group wanted to believe that the Rann government would be to blame for the possibilities ahead. And of course Opposition politicians relished the opportunity to support the RLCAG (RLACAG) campaign.
Anxiety, ignorance and vested interests saw the conspiracy theories gain momentum in Lower lakes communities. Some of the more rational community members felt intimidated by the fervour generated and kept their heads down.
One only has to look at the state of the Lakes now and recognise that it has not been Rann’s Weir that has caused the disaster – but a natural phenomenon exacerbated by a century of mismanaged extraction for irrigation – there is no weir but there is an environmental disaster. Casting blame has become a more complex process than just focussing on a temporary weir.
And yet the ‘anti-weir’ ideology of the RLCAG continues – they are now resisting attempts to protect the Finniss and Currency Creek wetlands and are opposing the notion of any barrier – presumably they are prepared to see the continued destructive effects of dessication upon the aquatic environments they claim to value. Their suggestions that these vast exposed areas could be effectively treated with lime and replanting (while advocating a minimum of disturbance !!) lack credibility – and yet they form the basis of their ‘10 point Action Plan’ to “Save the Lower Lakes”, - while most of the remaining points are generic vision statements that few would question.
As aggrieved as groups like RLCAG might feel that they are not being consulted – if their continued obstructive negativity is wrongly interpreted as representing the view of their community – and the government delays action that is urgently needed, for purely political purposes – we will all suffer and the very environment these groups purport to care about will particularly suffer – to a far greater degree than they have already.
On the other hand, if the RLCAG could use its proven skills to publicise the crisis in the Lower Lakes and support the actions needed (rather than to persist with a dogged determination to fight the governments’ every move) – their credibility and effective contribution to the environment we all fear for, would be greatly enhanced.
Desperate times require desperate actions – and governments prepared to act on the advice of professional expertise – and not be delayed by futile attempts to get a coherent and rational community consensus from people who are determined to disagree.