''We were told this would probably not be more than 20 metres, and I guess I must live about 21 metres above because it didn't quite get there,'' Lisa Brennan said as she surveyed the flooded shopping area from the roof of a multi-level car park.

Kerry Foley was not so lucky. He left home on Monday as water began lapping at his driveway and spent the night at the civic centre. ''The police were knocking door-to-door and said we could come here if we wanted,'' Mr Foley said. ''We thought it would be safer to go.''

About 40 shops and a dozen homes in Gympie were inundated. Brown waves lapped at a ''learn to swim'' sign at the municipal pool, which had gained a couple of metres in depth.

The Bruce Highway - the main road to the north and south of Gympie - is expected to be cut for days, with a side road the only way to reach the northern half of the divided town. The southern half could not be reached by vehicles from outside.

In a region devoted to beef cattle, fruit and sugar cane, there is enough fresh food for only two or three days. Food may have to be flown from Bundaberg, which is only just starting to recover from the floods.