The great flood of 1956 was the worst on record and an event described as 'the greatest catastrophe in the States History' Filling not only the Murray but the Darling too (a rare event). The rivers joined forces at their junction in Wentworth NSW and from there the only way for the water to go is down (through SA). According to Riverland author Graham Irwin in his book 'A brief history of Barmera' at the height of the flood, in late August, the River and Lake Bonney 'merged to form an unbroken sheet of water, stretching from Barmera to Moorook - 17km away. Barmera have a 1956 flood marker on the banks of Lake Bonney.
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