The director of the Murray-Darling Freshwater Research Centre, Dr Ben Gawne, says the government’s pledge means more water for riverside woodlands during dry spells.IT SOUNDS like a lot of water, and it is – the extra 450 billion litres of water that Julia Gillard has promised to save for the rivers and wetlands of the Murray-Darling Basin ticks most environmental boxes.
Where the river was likely to get 2750 billion litres, the government now wants to give it 3200.
Modelling by the Murray-Darling Basin Authority found injecting the additional water now on the table would significantly improve the health of key sites, such as the red gum and black box forests along the Murray River in northern Victoria.
It would mean an extra 30,000 hectares of flood plains will be more regularly inundated and there would be modest improvements at the famous Lower Lakes, the Coorong and Murray Mouth in South Australia.
Dr Ben Gawne, director of the Murray-Darling Freshwater Research Centre, says all this means more water can be delivered to riverside woodlands during dry spells, meaning less time between drinks for ecosystems that are home to rare parrots and other birds.
If regular flows do not occur, organic matter such as dead leaves can build up. When the drought breaks and there is a flood, that matter is swept into rivers and depletes oxygen in the water, turning it black, and killing fish and crustaceans. Last year, thousands of Murray cod died due to black water.
When flood plains don’t get enough water, salt builds up in the soil. When the rain returns that salt content is swept into rivers, damaging the ecosystem.
But as always with the Murray-Darling, there is a catch or two.
Authorities are concerned that increased environmental flows cannot be delivered without swelling rivers at man-made and natural choke points, potentially flooding bridges, roads and properties.
The modelling assumes that these problems will be fixed, but if they are not, earlier analysis has shown that the environment won’t benefit as much as it should from the extra water.
Labor has put $200 million on the table to try to address this problem through steps such as raising bridges and increasing the size of existing dams. Whether all this can be done without affecting personal property and people’s lives is unclear, though the government has given itself to 2024 to work it out.
To calm farming communities, who two years ago were burning copies of a basin blueprint proposing similar amounts of water being returned to the river, the government has found an extra $1.57 billion to make irrigation infrastructure more efficient and less leaky. This is on top of $12.8 billion already promised for infrastructure and buying back water from farmers.
The government says most of the extra 450 billion litres announced yesterday will be delivered by irrigation upgrades, but the actual amount of water delivered by these projects can prove woolly.
The fate of the Murray-Darling will ultimately come down to whether the basin states can agree. The promise of extra water has calmed South Australia, but enraged Victoria and New South Wales.
A deal is now within their grasp and the benefits are clear, but it is by no means guaranteed.
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