Politicians, are saying, it’s the drought, not the cotton growers who have caused the Darling River’s present environmental crisis.
Before we fall for this, let’s consider how the Murray Darling has maintained itself for thousands of years:
• It had regular high seasonal flows which replenished its wetlands, recharged the floodplains, topped up ground water and initiated ecosystem breeding and growth cycles.
• High seasonal flows basically flushed the system, distributing organic matter and diluting localised potentially high salinity and aerating the water.
• The ecosystems of many species were adapted to times of drying out. drought or low rainfall is part of the river’s ecosystems seasonal cycle.
But large water users such as cotton growers have successfully lobbied governments to allow:
• Storage of seasonal high river flows thus virtually eliminating the River’s natural high flows at environmentally productive times.
• Flood plain water diversion and harvesting to maximise upstream storage opportunities, which drastically reduces the seasonal revitalisation of flood plains.
• Large scale irrigation developments and other intensive farming adjacent to waterways which contribute to organic and fertiliser runoff into the river raised levels of which when added to low flow rates and higher temperatures inhibit many native species breeding cycles but encourage blue green algae growth.
• Irrigation and environmental flows at peak crop growing times, thus keeping water in wetlands (the rivers nurseries) when they should be drying out, and of course this means that water is not available to the wetlands when environmental beneficial
• Management from natural wetlands such as the Menindee Lakes timed on the basis of reducing evaporation loss, with little concern for it’s environmental health. In fact taking a further 70GL in the northern basin for irrigation from it’s potential inflow.
So don’t cry for the cotton growers. They were just successful at lobbying our politicians.
Instead punish the politicians who were too lazy or corrupt to see the disaster their decisions would cause.
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