The 1956 Murray River flood involved the rising of waters in the Murray River and flooding of many towns in New South Wales, Victoria and South Australia. The flood was and still is considered the biggest flood in the recorded history of the Murray and described as "the greatest catastrophe in South Australia's history",[1] although few lives were lost.
The flood occurred due to higher than average rainfalls in Western Queensland and heavy rains in the proceeding three months in the Murray-Darling basin.[2] Flood waters moved down the Murray and Darling rivers for seven months and peaked between 11 and 14 August at Merbein in Victoria[3] and 12.3 metres (40 ft) at Morgan in South Australia.[2] Inflow into South Australia peaked at 341 gigalitres per day, the highest on record;[4] the next highest on record is 220 gigalitres per day in 1931.[5]
From upstream to downstream, flooding occurred in the towns of Wentworth in New South Wales; Colignan, Iraak, Mildura, Nangiloc, and Red Cliffs in Victoria; and many South Australia towns including Renmark, Mannum and Murray Bridge.[6] Some areas were flooded up to 100 kilometres (62 mi) from the natural flow of the river.
As a result of the flood, the Menindee Lakes were constructed to store high flows from the Darling River.[2]