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  • Facing Reality - Lakes Need Water
    were to arise The Miocene history of the lower half of the Murray Darling Basin and the saline nature of soils bordering the river particularly in South Australia dictates that the Murray s water will progressively become more saline as one travels downstream Much of the lower MDB was inundated by the sea for thousands of years and this legacy remains today A truism of horticulture is that a plant can be grown with less water in a low salinity medium when using low salinity water lower than more saline soils which require relative saline water A plant must be irrigated heavily enough to flush salt from the root zone to prevent build up during irrigation with higher saline water This constant leaching is not required with low salinity water and highlights how less water is used when the quality off the water is good Obviously irrigators in South Australia relying on the River Murray have learnt to deal with more saline water than their counterparts upstream in other states They still need to be productive but they also need to be more astute with the selection of crops or similar food industries which can best tolerate the salinity we know to exist here Irrigation practices have to be designed around the water quality known to the area Conservation of water during irrigation has rarely been a consideration and denying food grower s water is denying food for the community There is no other serious option It is alarmingly obvious that we will not continually receive adequate rains year after year without fail throughout the Murray Darling Basin On occasions there may be enough to fill the catchments and even fill the lower lakes for a short period However as the population increases the demand on the basin as a

    Original URL path: http://www.lakesneedwater.org/letters/facing-reality (2016-02-09)
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  • Seawater saved the day - Lakes Need Water
    LNW I notice on the Lakes Need water web site in the latest news segment 27 March 2010 that Professor Kingsford is quoted in a SMH article that Lake Alexandrina and Lake Albert are below sea level for the first time in 7 000 years I find that hard to believe or is he admitting that prior to 1939 because there were no Barrages that sea water saved the day

    Original URL path: http://www.lakesneedwater.org/letters/seawater-saved-the-day (2016-02-09)
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  • Tidal Flow - Lakes Need Water
    level inside the lakes is the same as the level at sea Only then does flow cease On a falling tide the same large surface area of the lakes provides a very high volume of water which then pushes out through the mouth as the tide falls at sea If the level fell only 10cm in the lakes on a single outgoing tide then that represents about 80 gigalitres of water that would have passed out through the mouth In volume that s equal to 80 sq km x 1 metre deep of water That amount of water would have carried sand and silt with it out of the system mostly scouring where there is greater restriction and is therefore travelling at a higher flow speed Fast flow is what carries silt along with it so that the scouring action is where it s most needed We can adjust how fast the rising tide flows into the lakes by allowing the inflow to access the lakes through all available channels and limiting the outflow on falling tides to a few channels The latter will add to the pressure Less restriction coming in less flow speed less scouring of silt back

    Original URL path: http://www.lakesneedwater.org/letters/tidal-flow (2016-02-09)
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  • Summary of Lower Lakes Situation - Lakes Need Water
    produced serious impacts amongst the worst of which are No outflow to the sea has meant that continuous dredging of the Murray Mouth has been necessary to keep it open and allow tidal flow to the northern end of the Coorong Water levels have dropped to 0 5m below sea level in the summer of 2008 09 and 1 05m below sea level in 2009 10 A further 0 5m drop could be expected this coming summer Acidification as a result of oxidation of newly exposed sulphidic lake beds has occurred The worst of the acidification has been in Currency Creek Loveday Bay and parts of the Finniss River The Clayton regulator has temporarily alleviated the problem in Currency Creek and the Finniss but Loveday Bay in the south eastern part of Lake Alexandrina has been left untreated Slumping and cracking of river banks downstream of Lock 1 has resulted in the loss of several cars and orders to evacuate some riverside homes have been given Plans for Lake Albert have changed over time The original pumping to keep the Lake full was stopped in June 2009 and it was decided to let the Lake dry out More recent information has suggested that the threat of acidification is so great that pumping will now recommence when water levels drop below 1m below sea level They are currently 0 4m below sea level Water salinities in the Lower Lakes have increased and the water cannot now be used for irrigation Some irrigators can now access water from a new pipeline from Tailem Bend This supply could also be under threat this summer from saline Lake water intrusion which even last summer went past Tailem Bend at times when conditions were unfavourable There has been a marked impact on wildlife Bird numbers

    Original URL path: http://www.lakesneedwater.org/letters/summary-of-lower-lakes-situation (2016-02-09)
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  • Bird Numbers Counterpoint - Lakes Need Water
    the upper South East drainage Importantly the decline of fresh water resulted from mismanagement of the South East drainage system many decades ago when fresh water ordinarily destined to reach the Coorong through Salt Creek was turned towards the ocean Today some work is being done to turn that situation around but it will be a slow process to return suitable flows through Salt Creek into the Coorong During the interview Minister Weatherill said in part that the Lower Lakes and Coorong were compromised by a lack of fresh water flows Assuming he meant River Murray flow again this is not correct as the only freshwater flows entering the Coorong recently have come from the South East out of the SE drainage through Salt Creek and into the lower Coorong View a map of the area here What about the Lower River Murray below Lock One Minister Weatherill agreed that damage in the Lower Lakes and Coorong has occurred and it is damage that should be compensated for The minister said how the government doesn t think it s gone past the point of no return although he told how we have gone horribly close This statement ignores the damage now done to riverine backwaters and lagoons as a habitat for freshwater birds Damage has been done by the insistence of letting freshwater out of the river into the lake instead of holding it in the river by means of a weir containing a lock The Minister then commented how water birds were not getting enough water and how these birds are showing major changes and declines in numbers None of the comments in this segment recognised that water birds fall into a number of categories and subsequently use different habitats Freshwater lakes and lagoons of a reedy nature are

    Original URL path: http://www.lakesneedwater.org/letters/bird-numbers (2016-02-09)
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  • Some Fool Invented the Wheel - Lakes Need Water
    then were salt water at high tide and flushed out at low so long as there was a river flow and of course the 56 flood cleaned the area out fairly well The old Greek fisherman baiting his long line with mullet waited until the inflow reversed so that he could safely wade out into the stream to cast the baited long line for huge mulloway waiting in the outflow No flow in the river now Then flood it with sea water and the oxygenation will fix part of the lakes problem and time will fix the rest it always has The drought of 1914 reduced the Murray at Waikerie to a series of puddles that one could jump across My grandfather related stories of the lakes and tide flows across the salt pans drying out to a stage where the salt could be scraped off the surface Population interferes with the natural order of things because man wants to experiment to discover sometime by intent and mostly by accident and having succeeded wants to sustain Another 2 8 billion over the next 40 years U N will just add to the environmental problems caused by consumption that we know

    Original URL path: http://www.lakesneedwater.org/letters/some-fool-invented-the-wheel (2016-02-09)
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  • Fundamental Logic - Lakes Need Water
    and continuing drought has reduced the available water to less than one third of the allocation well below even that which might be aspired to in a restructured and better managed future resource Irrigators and their communities are suffering throughout the basin And so While the drought continues with this large shortfall in available water caused by drought the environmental flows of fresh water needed to restore the Lower Lakes even to sea level are just not there the required fresh water does not exist Which means Either Lake and lower river levels will continue to fall with increasing salinity risk of irreversible acidification windblown storms of corrosive dust and physical impacts upon lake shorelines and river banks Or Sea water is allowed through the barrages to mix with the limited freshwater flows from the river to raise water levels to cover exposed lakebeds and reduce threats of acidification ie an estuarine environment is created But With an estuarine mix of salinities across the lakes there is an urgent need for a barrier at or near Wellington to protect the quality of water extracted from the river for human uses from saline contamination And with increasing lake salinity from summer

    Original URL path: http://www.lakesneedwater.org/letters/fundamental-logic (2016-02-09)
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  • Sanction the Weir - Lakes Need Water
    end of this summer by 21 GL And that s using last year s usage rate Minister Maywald reported on ABC 891 18th September 2009 that there would be a shortfall of 50GL for Adelaide s water supplies We need to understand the problems confronting the lower river below Lock One and take a serious look at the state of this final stretch of the river 1 Of the 80 wetlands below Lock One only three have any water and 14 are at an extreme risk of acidification 2 Any water below Lock One and moving into the intake pipes runs the risk of picking up acidified heavy metals from these at risk wetlands that could find a place in Adelaide s drinking water 3 Serious slumping and loss of land with cars taken to the bottom of the river and 20 holiday homes that are teetering and ready to topple The reality is that the weir must be started now The situation in the last section of this once mighty river is now at its lowest level and condition Given it will take 12 months to complete the weir It s possible that it s already too late As mentioned in the article Weir delays could cost River Murray the intake pipes below Lock One should be removed and re installed above Lock One at Morgan where water is cleaner and without the problems associated with the acid sulfate soil ASS conditions What you could be drinking So not only is the government not moving the intake pipes above Lock One they are also not building the weir below Lock One The government is hell bent on not pushing for the approval for the weir until Garrett makes his next statement on 27th January 2010 It s therefore a

    Original URL path: http://www.lakesneedwater.org/letters/sanction-the-weir (2016-02-09)
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