For decades, the rivers of the Murray-Darling Basin have been heavily regulated by dams and irrigation networks. As a result, the volume of water entering the ocean is about 60% smaller than 100 years ago. But nature broke through during massive floods over the summer of 2022–23, when heavy rains filled the Basin’s waterways.
The threshold for a flood on the Murray is when the daily water flow at the Victoria-South Australian border reaches 50 gigalitres a day. This flood reached 168 gigalitres a day – the largest in 66 years. A colossal plume of muddy floodwater reached 40 kilometres out from the Murray mouth into the Southern Indian Ocean.
