A helicopter will be deployed to drop large sandbags to reinforce a levee protecting critical water supply infrastructure east of Adelaide as Murray flooding in the region continues to increase.
The State Emergency Service says inspections of the levee at Cowirra near Mannum have revealed the need for strengthening work.
The chopper will be used to drop about 200 Bulka Bags, each weighing up to 1000 kilograms, in an operation expected to take between 12 and 14 hours on Thursday.
Downstream communities are bracing for the worst of the flooding with the peak in river flows forecast to reach Mannum and nearby communities by January 13.
High water levels moved through SA's Riverland region just after Christmas with the river there starting to fall.
The flooding has so far impacted about 3400 properties, including nearly 400 primary residences.
It has also closed 119 roads across river communities with nine ferries shut down.
Also on Thursday, the state government opened a third emergency relief centre at Murray Bridge following those established at Berri and Mannum.
The centres provide easy access to support services, including hardship grants, food relief, emergency accommodation and financial and personal counselling.
So far, the Berri and Mannum relief centres have helped more than 1600 people.
"This is an ongoing disaster facing communities all along the Murray River and people are not only dealing with the loss and hardship brought on by these flood events but are also starting to think about the clean-up," Human Services Minister Nat Cook said.
On Wednesday the state government established eight zones along the Murray in SA to progressively lift restrictions on river activities as the floodwaters recede.
Recreational activities, including fishing and swimming, were banned along the river late last year amid safety concerns as water levels rose to heights not seen for more than half a century.
Premier Peter Malinauskas said it made sense to treat the various parts of the river differently as the floodwaters moved through the system.
"By having these eight zones, we're acknowledging the fact that what is occurring in the Riverland is very different to what's occurring in Murray Bridge," he said.
Police Commissioner Grant Stevens said work was underway to develop a set of principles to guide the lifting of restrictions across the river zones taking into account flow rates, river heights, the condition of levees and river banks and the amount of debris at various locations.
Mr Stevens said officials hoped to lift restrictions as soon as possible but it was too early to tell when they would start to be eased.
The SA opposition has called for more clarity on when the bans will go to allow river communities to better plan ahead.
