What is the Murray mouth?

The Murray mouth is where the Murray River meets the sea at Goolwa in South Australia, on the south-east coast of the country about 100 kilometres south-east of Adelaide. The mouth is part of the Coorong, Lower Lakes, and Murray Mouth (CLLMM) Ramsar wetland site.

The Murray drains 14 per cent of Australia and travels about 2,508 kilometres before reaching the mouth, but the volume of water that actually reaches the sea is a small fraction of what once flowed naturally. Irrigation, weirs, and barrages along the river capture most of the flow for agriculture in the Murray-Darling Basin. The Goolwa Barrages, completed in 1940, separate the freshwater Lower Lakes (Lake Alexandrina and Lake Albert) from the saltwater Coorong and the Southern Ocean.

The Murray mouth has periodically closed during severe droughts, most famously during the Millennium Drought (1997 to 2009), when sand built up across the entrance and dredging was needed continuously to keep it open. A closed mouth disconnects the river system from the sea, with severe consequences for fish migration, the Coorong's hypersaline lagoon, and the internationally important migratory birds that depend on it. The Coorong Mulloway, the Pelican, and the Long-toed Stint are among the species at risk.

The Coorong was made famous by the 1976 Australian film Storm Boy, set around the relationship between an Aboriginal man, a young settler boy, and an orphaned pelican. The Ngarrindjeri people are the Traditional Owners of the Murray mouth and Coorong region. The mouth is monitored continuously as an indicator of the health of the entire Murray-Darling system, and end-of-system flow targets have been a major focus of the Murray-Darling Basin Plan.