LATE last year several of my friends sent off postcards as part of the Australian Environment Foundation’s Rivers Need Estuaries Campaign. You can still send a postcard and sign the petition here:
There is a choice of message, for example:
Maintaining artificial freshwater lakes using 7.6 kilometres of concrete barrages has:
1. Destroyed the Coorong-Murray River estuary;
2. Diverted water from upstream environments and communities to keep these artificial lakes supplied;
3. Not improved the water security of Adelaide.
I ask you to support moves to:
1. Remove the barrages from the Lower Lakes to restore the Coorong-Murray River estuary; and
2. Relocate Adelaide’s water take-off to a proposed lock downstream from Tailem Bend.
Signed K. Smith
Just today there has been a flurry of responses from Simon Birmingham Shadow Parliamentary Secretary for the Murray-Darling Basin to postcards sent last December. The Senator is mostly replying with a form letter as follows:
Dear Ms Smith
Thank you for your email regarding the Lower Lakes.
Firstly, in regards to basin reform, I encourage the Gillard Government to return to the reform process put in place by the previous Coalition Government. Labor has spent only a fraction of the $5.8 billion set aside by the Coalition to invest in efficiency upgrades. A sustainable solution to the Basin requires the Government to get serious about investing in the efficiency of the Basin.
Australians deserve a plan that gets the balance between the environment, communities and jobs right. Before the election Prime Minister Gillard promised to implement whatever the MDBA presented. I hope Minister Burke will take a more pragmatic position and ensures that we get a good plan based on robust evidence – not just any plan.
The Coalition is listening to people across the Basin and is working hard to ensure a sensible outcome is found. An outcome which restores the health of the environment, provides a strong future for regional communities and sustains Australia’s record as a food producing country.
In regards to the Barrages however, I must strongly disagree. There exist very real and very serious environmental consequences if the river does not, with at least some regularity, flush through the Lower Lakes and expel chemical, salinity and sediment build ups (much of which are the result of agricultural run-off) to the sea.
Many people that advocate removing the barrages separating the Lower Lakes and Coorong, which would essentially turn the lakes into a permanent saline state, do not extend the argument about natural state upstream. When Charles Sturt sailed down the river in 1832 there were no locks or weirs and minimal diversion for irrigation.
There were, no doubt, during periods of drought, occasions when the Lakes and Lower Murray did have sea water incursions, however, when drought passed, the volume of water which regularly flowed through the system and into the Lakes pushed salt water back through the mouth. Man’s management of the system and use of water nowadays prevents such regular flushing as nature would have done.
Turning the lakes into a saline ecosystem ignores that they have been largely freshwater, even before the barrages were built, and are of great ecological importance. I encourage you to download the 75 page document entitled ‘A Freshwater history of the Lakes’ available at http://www.gwlap.org.au/docs/A%20Fresh%20History%20of%20the%20Lakes%202004.pdf
If the barrages were removed and lakes were flooded with seawater without significant additional fresh water flows, it is highly likely that they would turn into a dead sea and, during periods where there is little water to flush the salt and sediment through the mouth, the ecosystem may collapse, with salinity and problems spreading up into the main channel.
The recent drought has shone a spotlight on a problem that should have become evident with the closure of the Murray Mouth back in the early 1980’s. Fixing this will require trade-offs – there is no going back to the natural state of the river, but equally maintaining healthy communities along the river requires us to keep it healthy from the mouth up.
It is our responsibility to ensure that we get the balance between the demands of social, economic and environmental needs right. I will certainly be judging the MDBA Basin Plan against all of these criteria.
Once again, thank you for bringing your concerns about the Murray-Darling Basin reform process to my attention.
Shadow Parliamentary Secretary for the Murray-Darling Basin
Several of my friends have emailed me pleased to receive this response and asked how they might best “engage” the Senator in discussion. Others have indicated to me they are angry that the Senator dared quote ‘A Freshwater history of the Lakes’ by Sim and Muller to them.
I am providing the following information for those wanting to reply to the Senator. And I encourage detailed replies. In fact consider emailing the Senator on this issue even if you haven’t received an email from him – or sent him a postcard. His address is email@example.com. You might consider copying your reply to your local federal member and also Tony Burke, the federal water minister. His address Tony.Burke.MP@environment.gov.au
Suggested information that could be included in a reply:
The Lakes Don’t Have a Freshwater History
I am surprised that the best information you can provide in support of keeping the 7.6 kilometres of barrage across the bottom of the Murray River is the report by Sim and Muller ‘A Freshwater history of the lakes’.
This report is essentially a compilation of historical anecdote from early European visitors and settlers suggesting that the lakes contained fresh water. This is not disputed, but the same lakes were often full of brackish water and occasionally seawater. In estuaries water quality is always changing: with the tides, with the seasons and with the climate in the upper catchment. To say that the lakes were predominately fresh and therefore must be always kept fresh is to suggest a steady state when none existed.
Charles Sturt Found Salty Water
You quote Charles Sturt sailing down the river in 1832, it was in fact February 1830, and that this was before locks, weirs and diversions for irrigation. Exactly! And what did Captain Sturt report? He wrote that Lake Alexandrina changed from initially fresh to suddenly salty as he sailed across it and that the Mouth was closed over with sand bars and shoals. Indeed before irrigation the lake was not always fresh and before irrigation the Murray’s Mouth often closed-over. So we should not be concerned by these events and there is no reason to blame them on upstream irrigation.
Without the Barrages the Lake Would Not Become a Salt Marsh or Dead Sea
Like many South Australians you appear concerned that without the barrages, and given current upstream diversions for irrigation that the lake could turn into a salt marsh or at least a dead sea.
There are many very salty lakes in South Australia. But unlike most lakes in South Australia that are dependent on local rainfall, in contrast the Murray is feed from the Snowy Mountains in NSW and Victoria. This provides a regular flush of freshwater each spring.
Lake Alexandrina, even with upstream diversions, still has what is called a “positive hydrodynamics” meaning freshwater inflows are greater than evaporation. In fact freshwater flows into the Lower Lakes are still very significant. So there is no risk that the lakes will become a dead sea.
The Tides of the Southern Ocean Could Flush Out Chemicals and Sediment Build-up
Senator, why would you want to use precious freshwater to flush the lakes and expel chemical, salinity and sediment build-ups when the tides of the Southern Ocean could do the same job with seawater? Back in 1856 South Australian Surveyor General George Woodroffe Goyder suggested that the natural rock bar across the Mundoo channel be removed to improve tidal inflows and outflows along the Mundoo channel and thus improve natural scouring of the Murray’s Mouth.
Why not remove the barrages and let the tides of the Southern Ocean flush the Lower Lakes of chemicals and sediment build-up. This is the natural solution and the solution for every other major river system in Australia.