River zones to guide SA's Murray reopening

Eight zones have been established along the Murray in South Australia to progressively lift restrictions on river activities as floodwaters recede.

But the move has sparked calls for more clarity on when and how the bans will cease.

Recreational activities including fishing and swimming were barred along the river late last year amid safety concerns as water levels rose to heights not seen for more than half a century.

The peak has now passed Renmark and other Riverland towns but is yet to reach communities downstream, including Mannum east of Adelaide.

Premier Peter Malinauskas said it made sense to treat the various parts of the river differently as the floodwaters moved through the system.

"Restrictions are never an easy thing to apply. It hurts some businesses, it makes life inconvenient for some communities," he said on Wednesday.

"But naturally when we've got a huge volume of water coming down the river at a record pace, that provides dangers as does the amount of debris.

"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."

Police Commissioner Grant Stevens said work was under way to develop a set of principles to guide the lifting of restrictions across the river zones.

They will centre on 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.

Riverland Liberal MP Tim Whetstone said it was disappointing the announcement provided no clarity for river communities.

"Safety for those in river communities is critical, but many businesses and residents are keen to have some certainty about when recreational activities will return," Mr Whetstone said.

"Summer is usually the peak period for tourism along the River Murray and the restrictions are clearly having both an economic and social impact on communities who are already suffering because of the floods."

Mr Whetstone said the opposition wanted to see specific trigger points at which restrictions would be lifted, so communities could plan ahead.

The flooding in SA 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.

The Murray is expected to peak at Waikerie and Morgan this weekend and at Blanchetown, Swan Reach and Mannum by January 13.

This week, the continued surge breached or inundated a string of agricultural levees including those at Mypolonga, Toora, Mobilong, Cowirra, Wall Flat, Long Island and Long Flat.

The SA State Emergency Service said more issues with levees could be expected as peak flows moved down the river.

Authorities are also keeping a close eye on the release of more water from the Menindee Lakes in NSW which would eventually flow into the Murray.

SA SES Chief Officer Chris Beattie said the water would start to have an impact in SA in early February and was not a great concern at this stage.