Four-metre waves could eat away at southeast Queensland's beaches in coming days as a tropical low sweeps along the coast.
But forecasters don't believe the weather system will strengthen into a cyclone, and it's not even expected to dump much rain.
Authorities are on alert for the arrival of the low-pressure system but are relieved it's unlikely to strengthen after three weeks of devastating weather in other parts of the state.
Emergency Services Minister Craig Crawford is in the flood-ravaged north, and says major roads have been severely damaged.
He said it would take weeks to determine the final repair bill but it could amount to tens of millions of dollars.
There are concerns too that flood waters could spread the devastating soil disease Panama TR4 to banana farms throughout the Tully Valley after an outbreak on one property was detected last month.
The low in the Coral Sea is about 1300km northeast of the Sunshine Coast and is tracking steadily south towards the coast, where its effects will be felt from Wednesday morning.
It should remain offshore and below cyclone strength, but it is expected to generate gale-force winds and large swells that could cause beach erosion.
Dangerous surf conditions are expected to develop during Wednesday morning along the east coast of Fraser Island and the Sunshine Coast. The Gold Coast will see similar conditions from Wednesday afternoon.
High tides on Wednesday and Thursday could cause some inundation in low-lying areas prone to flooding, but the system is not expected to produce much rain.
Mr Crawford said three weeks of wild weather had taken a toll on communities, including Yam Island in the Torres Strait, north and far north Queensland, and swathes of the state's western interior.
"It's quite evident - just the sheer size of this weather system and the storms and floods that have occurred," he told reporters in Innisfail.
After meeting with anxious Tully banana growers, and visiting devastated Ingham, he'll head west to Mount Isa on Wednesday to talk to mayors still dealing with inland flooding.
"We've still got towns and communities cut off," Mr Crawford said.
"There's barely a few parts of Queensland that haven't been touched by storm activity in the last two to three weeks."
The Bruce Highway north and south of Ingham reopened on Monday, but lower speed limits are in force on some damaged stretches.
In the far north, engineers are investigating a large crack that has opened up on the Palmerston Highway. There have also been landslips on that highway, as well as the Gillies Range Road and Kennedy Highway.
And the Burke Developmental Road, north of Normanton, is still under a significant amount of water and is expected to be closed for some time.
© AAP 2018