Dredging of the Murray Mouth resumed this week for the first time in since the 2022/23 floods, to help protect the health of South Australia’s Lower Lakes and Coorong.
While the floods and high midyear flows combined to reduce the need for dredging, recent dry weather means sand has started to once again build up at the Murray Mouth.
Dredging is used to remove the build-up of sand at the Murray Mouth and two adjacent water channels, ensuring a clear passage of water flow between the Southern Ocean and River Murray system.
Previously undertaken by two small dredges, the restarted operations will now use one larger dredge currently located at Tauwitchere Barrage.
It is estimated that more than 14 million cubic metres of sand has been removed at the Murray Mouth since 2002.
Minister for Climate, Environment and Water, Susan Close, said the resumption was a stark reminder of why we need the 450 gigalitres of environmental flows promised under the Murray Darling Basin Plan.
“Ideally, the mouth of our country’s biggest river should not need to be dredged continuously to keep it open,” the Minister said.
“This is just another expense caused by the failure of upstream states to ensure enough water flows down the system to ensure the health of the whole river system.
This is why it is so fundamental that the Murray Darling Basin Plan, including the 450 gigalitres of environmental flows, is delivered in full.”
SA Water procures the dredging services at the Murray Mouth on behalf of the Murray Darling Basin Authority (MBDA) under the Murray-Darling Basin Act (2008).
The MDBA fully reimburses SA Water for all costs incurred under the Murray Mouth dredging services contract, undertaken by SA-based company Maritime Constructions.
Minister Close said “while the floods provided an ecological lifeline to the Coorong and Lower Lakes, forecasts now indicate we are poised for a drier period in the foreseeable future.”
