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  • Socio_Economic_Impacts_Feedback - Lakes Need Water
    in the Lower Lakes for thousands of years during times of low flows Prior to the construction of the barrages the Lower Lakes were estuarine in nature and not purely freshwater systems Please refer to our website http www lakesneedwater org case for seawater Specifically only one management action Action C10 Introduction of minimal amounts of seawater to avert acidification of Lake Alexandrina even considers the use of seawater and even then it is regarded as a last resort option with seawater to be used only in minimal amounts The rationale states that it may avoid acidification although could make it worse whereas in reality there is no scientific evidence to suggest that seawater would make the situation worse In fact inundation by seawater has been demonstrated to be a proven technique for managing acid sulphate soils elsewhere in the world Climate scenarios By now it is also widely recognized that the Wet and Median climate scenarios offered by the CSIRO are optimistic scenarios not probable scenarios Accordingly planning should focus on the Dry and Extra Dry scenarios with realistic assumptions about future freshwater flows not optimistic ones This view is also supported by DEH chief executive Allan Holmes who states Government strategies to manage the acidification problem have changed in recent months from assuming Murray flows would return to normal to expecting little flow for the next five years in the river http www abc net au news stories 2009 07 29 2639993 htm Further the use of seawater should not just be limited to the Extreme Dry scenario but is equally applicable to the highly probable Dry climate scenario Barrages The management actions also gloss over the highly adverse environmental impacts of the barrages Although the importance of fish passages is acknowledged for example in Action A10 Fish passages through to the Coorong at Goolwa The management actions do not adequately address the deleterious effects of the barrages The presence of the barrages by causing an abrupt change in the water environment and reducing tidal range has contributed to massive habitat degradation Please refer to our website page http www lakesneedwater org barrages Also please refer to the report The River Murray Barrages Environmental Flows Report produced by the Murray Darling Basin Commission in 2000 Ramsar The Ramsar listing is for a freshwater system that has been artificially sustained by the presence of the man made barrages for 70 years and by now it should be clear that the Murray Darling Basin no longer supports the flows to artificially sustain this purely freshwater regime Meeting the Ramsar obligations would be much better served by an estuarine scenario than by that of the RLCAG no water scenario since a modified but healthy estuarine wetland would be created rather than an acidified small pool of water with vast exposed dry lakebed exposed exacerbating the future potential for increasing acidification Please refer to our website page http www lakesneedwater org ramsar Flow management LakesNeedWater org believes it is feasible that barrages

    Original URL path: http://www.lakesneedwater.org/letters/socio_economic_impacts_feedback_7_august_2009 (2016-02-09)
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  • A Likely Outcome Should The Lower Lakes Become Estuarine - Lakes Need Water
    molluscs etc The real savings are that it is not then necessary to try and bleed freshwater from the Murray River to maintain the wide expanses of the lakes where very large amounts of water are lost to evaporation and soakage every year Of all River Murray water that enters South Australia each year the volume taken by evaporation from Lake Alexandrina is more than what the river generally contains between the border and Wellington By holding that amount of river water back from entering the lakes we can maintain healthier wetlands along the river and still have some left over to regulate portions of seasonal flow of fresh into the lakes to maintain the estuarine conditions there Most estuarine life responds to periodic low salinity fresh flows to stimulate life cycles The Eastern Mount Lofty drainage would likely contribute periodically during seasonal rain periods But the most significant gain outside of water conservation benefits in the core business of RAMSAR is the provision for a continuance of traditional feeding areas for intercontinental migratory birds The increase in inter tidal zone feeding areas for waders would be enormous The intent of RAMSAR is to provide assured feeding areas for migratory waders However they rarely benefited from the freshwater systems that we in the past had turned the Lakes into It recently has been a reed dominated system with a steady pool level with no inter tidal feeding zones and certainly shunned by most waders Some still tried to make do in the Coorong but man has killed the greater proportion of that anyway Most of the birds on or around the lakes themselves were sedentary or nomadic birds oriented towards open water and reeds There is a good deal of concern by the scientists and the community with regard to the Coorong Particularly about the declining narrow inter tidal zone for wader feeding For fish populations the explosion towards the middle and top of the food chain base in the tidal lakes would be enormous There are numerous species that would inhabit the estuarine lakes Species such as the marine estuarine Black Bream and Mulloway would also take up residence with many coastal pelagic sea species not far behind Other examples by common name would be four species of Mullet generally found along the southern coasts They include Coorong mullet Yelloweye mullet Sand mullet and the very large Sea or Jumper mullet juveniles of which often enter estuaries during their developmental stage Other species would include Flounder Australian Salmon Flathead Anchovy Marine Hardyhead Long finned Goby Congolli and the amazing Short headed lamprey a dual marine and freshwater species that would only migrate with the aid of a fish way or ladder through a permanent weir at Wellington Similarly migrating Galaxias sometimes known as native trout are a freshwater species that rely upon tidal areas to spawn This amazing specie is born at sea and then returns to its freshwater environment to reach maturity Whether we experience further catches of

    Original URL path: http://www.lakesneedwater.org/vision/a-likely-outcome (2016-02-09)
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  • Tidal Flows in The Coorong and Lower Lakes - Lakes Need Water
    Coorong on the other hand is long and narrow and for our example we ll consider just the northern section It is about 50km from Pelican Point to Hells Gate located part way down the Coorong For ease of reckoning the figures we ll assume the Coorong is on average about 1km wide That s equal to 50 sq km of surface area Recall that one Gigalitre corresponds to 1 square km x 1 metre deep If you elect to double the depth of the Coorong from one to two metres deep then you would have a volume equal to 1 sq km x 2 metres deep being 2 Gigalitres The sq kilometre x 1 metre deep figure is useful when referring to and measuring from a map to calculate how many square km s would fit In the previously mentioned 50 sq km section of the northern lagoon of the Coorong given the elected depth is one metre a water body of 50 Gigalitres would be required to fill the void If you think it s only half that depth then a half metre over 50 sq km would require 25 Gigalitres Then we need to understand flow rates eg volume of flow over a given period of time An example of flow rate is often found on sprinklers showing the rate in litres per hour Volume over a given time Pressure at the sprinkler will influence flow rate dependent on how much you turn the tap on Turn the tap almost off and the pressure at the sprinkler head reduces because the flow has been reduced by a restriction at the tap Assuming 5km hour flows six hours equals 30km distance But we have already said that the upper or Northern Lagoon of the Coorong is 50km long and therefore the water doesn t quite reach the end In truth though only the top 2 hours either side of high tide would be still high enough to maintain the flows in at 5km per hour The balance is slowing down So it didn t make it much past the halfway mark down the North Lagoon on a single tide even if the mouth area had been wide and deep It s too long and narrow and a little like tipping a bucket of water out into a gutter where it takes a while to move along But if it s long and narrow then the wind will also push it along In the North Lagoon scenario it does When the wind blows from the north west over a period of about two days it tends to hold incoming high tide water in the North Lagoon by pushing it down towards Hells Gates where it holds it while the particular wind prevails often over several days The levels at Hells Gates rise and some of the flow manages to squeeze through the much reduced and very narrow channel of here The NW wind then holds the water against a

    Original URL path: http://www.lakesneedwater.org/letters/lower-lakes-and-coorong-tidal-flows (2016-02-09)
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  • EIS Submission T. Harden - Lakes Need Water
    consequences of wind erosion and deposition of exposed lake bed soils at shorelines and beyond are happening now Click here for detail and photos This issue has been overlooked in the Draft EIS Which means that 2 Water is required to cover the exposed lakebed to levels significantly higher than the 1 5 AHD trigger level which is much too low and much too late Click here for detail and photos Which means that 3 Sea water must be allowed to enter the lake system as soon as possible as there is insufficient freshwater available for this purpose Click here for detail and photos Which means that 4 The temporary weir at Pomanda Island was needed months ago and must be completed as soon as possible to protect urban and irrigation water intakes from saltwater contamination from the lakes Click here for details and photos And so 5 The EIS must factor in the windblown soil issue acknowledge the unavailability of fresh water to address this problem acknowledge the immediate need to flood the lakes with an estuarine mix of sea water with fresh water and acknowledge the need for construction and completion of the Pomanda Island weir as soon

    Original URL path: http://www.lakesneedwater.org/letters/eis-submission-t-harden (2016-02-09)
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  • The Debate - Lakes Need Water
    flux It is dynamic and there is no such thing as stability Human beings have tried to make the environment more stable by technology and in doing so we have created the false expectation that things will always be the same as we have come to expect The debate over the issue of letting seawater into the Lower Lakes as a means of preventing the further development of acid sulphate soils has degraded into a fight between the two opposing sides those against and those for Please read the arguments against seawater and the arguments for seawater Some of these arguments raised by both sides are outlined and discussed below The past history of the Lakes Reliance on indigenous knowledge Ramsar Convention on Wetlands obligations Bioremediation Releasing more water from upstream The problem of evaporation from the surface of the Lakes The weirs The problems of a dry lakebed Engineering aspects of seawater in the Lakes What is natural We all have our pet theories about what it is depending on our particular priorities We must weigh up the alternatives of several unnatural situations and decide what is best for the environment Subpages 12 Against Bioremediation Engineering aspects of seawater

    Original URL path: http://www.lakesneedwater.org/debate (2016-02-09)
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  • Features - Lakes Need Water
    13 April 2012 Save the Murray Restore the Estuary Feb 2012 Lower Lakes Local History May 2011 River Murray Barrages Environmental Flows 17 October 2010 Summary of Murray Futures Securing the future report 6 June 2010 Summary of the Lower Lakes Crisis 24 January 2010 Remediation by Seawater 6 January 2010 Acid Sulphate Soils and Seawater 3 January 2010 Fencing on public land when is a fence a deathtrap 4

    Original URL path: http://www.lakesneedwater.org/feature (2016-02-09)
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  • Expert Opinion - Lakes Need Water
    University of Ballarat favours flooding the lower lakes with sea water in his ABC interview download dated 6 January 2009 and his Crikey posting dated 9 January 2009 Former Australian of the Year Tim Flannery supports building a barrage higher up the system and for the Lower Lakes to be flooded by the sea in this article in the Australian 12 July 2008 Dr Jennifer Marohasy a Director of the Australian Environment Foundation explains how the lakes and Coorong can be saved with seawater and offers an historical perspective in her Online Opinion posting dated 14 August 2008 Associate Professor David Paton at the University of Adelaide proposes removing Lake Albert from the River Murray system to create wetlands in an Adelaide Advertiser article dated 14 December 2008 Ian Kowalick former Murray Darling Basin Commissioner says the problems are critical in all rivers throughout the system and that it is not possible for the basin to return to the natural system that existed before the building of the locks and barrages Adelaide Advertiser 30 July 2009 Rob Freeman Chief Executive of the new Murray Darling Basin Authority says that given the likely impacts of climate change on the Basin s

    Original URL path: http://www.lakesneedwater.org/experts (2016-02-09)
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  • Reports - Lakes Need Water
    Reading Maps About Us Links Act Now More Reading Reports The reports below are our top picks for learning about the River Murray and the water crisis as it affects South Australia and the Lower Lakes Murray River Barrages Environmental Flows Murray Darling Basin Commission 2000 And a few key points from the report Myth and the Murray Measuring the Real State of the Environment Jennifer Marohasy Water Planning and

    Original URL path: http://www.lakesneedwater.org/more/reports (2016-02-09)
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