A total ban on non-essential activity on the Murray River in South Australia has been put in place, as the Riverland faces its worst flooding in half a century.
Flood water from Queensland, New South Wales and Victoria has been flowing down to the state for weeks, merging into the Murray River, with the peak predicted to hit at Christmas.
South Australian premier, Peter Malinauskas, said while people have known for weeks it was coming, there is still anxiety as the waters close in, particularly because it was not clear how the peak would act.
“On the ground, people reference historical markers [from floods in 1956 and 1974) versus the flow rates, but there’s a live question about the accuracy of those flow rates back in the time,” he said.
The actual damage would depend on how much water is reabsorbed on flood plains, how deep the channels are now, and other variables.
“It’s a natural disaster everyone knew was coming,” Malinauskas said.
“There’s an inevitability, but it’s so slow moving it brings its own type of psychological strain. Overall people are resilient and prepared. But there’s still anxiety, clearly.”
Malinauskas announced on Tuesday that boats, swimming, fishing and other activities have all been banned, just before the popular summer tourism season should be taking off.
“This is a decision that hasn’t been taken lightly,” Malinauskas said.
“This is a closure that takes effect immediately and will be in place for some time to come as we confront the ever increasing flows of water coming down across the border.”
Malinauskas said the ban was in place from the state border to Wellington, which is almost at the mouth of the river, to protect the public and levee banks, and to allow more flexibility to cut off power.
“The river has been closed to non-essential activity to protect people’s safety, to protect levy banks from damage, particular from waves that are created by motorised vessels going up and down the river, and then thirdly, it actually provides more security around the energy connections that we need to see in place for as long as possible,” he said.
The daily flows across the border are projected to reach up to 220 gigalitres a day, at a time of year when they are usually fewer than 20GL.
Rising waters are already inundating homes and businesses, forcing people to evacuate, bridges to close and ferries to stop operating, endangering wildlife and threatening farms.
About 4,000 homes (many of them holiday houses) are expected to be flooded, despite the levees that have been built to hold back the water.
The latest flow report shows the peak will reach Renmark, just over the Victorian border, around Christmas or Boxing Day.
It then travels down, through Berri and Waikerie and Mannum, before reaching Lake Alexandrina at the bottom of the system between 6 and 17 January.
For the first time in decades, dredging to keep the Murray mouth open has halted as the water flows through to the sea. Barrages, usually closed to stop sea water coming into the river system, have been opened to let the flood waters out.
Earlier on Tuesday, Malinauskas told the ABC that SA communities have been preparing for weeks for the water.
“It’s been a slow moving event but it’s becoming increasingly real,” he said.
“We know that it will be with us for some time … there will continue to be high flow rates throughout the early months of next year. We know the cleanup effort is going to be probably an even bigger challenge than the preparations we’ve put in place till this point.”
Malinauskas said while it was difficult to talk about with the imminent “human tragedy”, the water would also bring “profound environmental benefits” through the scouring of the Murray mouth and the flow of water into the Coorong.
