Unprecedented floodwaters south of Brisbane are expected to swamp more than 300 properties in Logan over the next 24 hours, including about 200 homes.
That figure already includes more than 100 flooded homes and businesses in low-lying areas of Logan, as the Albert and Logan Rivers swell to unprecedented levels.
Logan Mayor Luke Smith says flood modelling for low-lying areas along the Albert River is changing by the hour, but so far 211 homes are expected to go under.
"The Albert River is higher than we predicted it to be," he said.
"The river is at an unprecedented state and we are watching now what that'll mean for our localised flooding.
"We are seeing roads cut off even more and we are seeing heavier inundation than predicted."
He said the Logan River has almost reached its predicted peak for midday tomorrow and is staying higher for longer than expected.
"It actually could rise above the Waterford Bridge on Logan River Road," he said.
Water is already lapping just under the bridge. Evacuations began earlier today.
