Just how “natural” are the current blackwater events across the Murray Darling Basin?
It is true the problem has been brought about by many years of drought, followed by last year’s unusual summer flooding.
Blackwater occurs naturally when accumulations of organic matter, such as eucalypt leaves and twigs, decay in wetlands or waterways, drawing oxygen from the water and often causing fish deaths.
To say the past drought had the fingerprint of climate change and bring up a degree of human contribution would certainly start a lively debate; however the lack of river flows attributable to irrigation diversions during this period is indisputable.
This lack of even minor flooding over this drought period has contributed to the current extreme level of organic matter mobilised.
Had environmental flows been available to recreate even a minor flood during the past drought the most extreme effects of the Blackwater events would have been reduced.
This is another very obvious example of the need for the Murray Darling Basin Plan and an environmental water reserve.
Environmental Farmers Network spokesperson
150 Maneroo Rd.