At times of greater river flow and rough seas, the two bodies of water would erode the sand dunes to create a new channel leaving the old one to silt and disappear.

Firstly, the flow from the west passes along a passage known as the Goolwa Channel which is bounded by Hindmarsh Island to its north side.

[8] It was suggested that the Murray may have taken a different course to the ocean, via Burra, South Australia and emptied into the Spencer Gulf,[9] before being 'defeated' by the rise of the Mt Lofty Ranges.

[11] During the later 19th century with the discovery of gold, and the development of sheep and wheat farming along the Murray and its tributaries, the river became a major thoroughfare for the carriage of goods and produce.

[12] Without the 24-hour dredging, the mouth was at risk of becoming silted and closing, cutting the supply of fresh seawater into the Coorong, which would then warm up, stagnate and die.

The Murray Mouth is immediately adjoined on its northern and eastern sides by the boundary of the Coorong and Lakes Alexandrina and Albert Wetland Ramsar site.