Rockhampton is preparing for its most severe flooding in more than six decades, with floodwaters expected to rapidly rise throughout the day.

The Fitzroy River is expected to peak at 9.4 metres late on Wednesday, a level that has not been seen in the city since 1954.

The deluge is moving downstream, after remnants of ex-Cyclone Debbie dropped record-breaking rain throughout central and north Queensland.

Residents have been urged to prepare early, with the river expected to reach the major flood level of 8.5 metres later today as water from further up in the catchment moves towards the coast.

Rockhampton Mayor Margaret Strelow said water was expected to start moving into homes and businesses by Monday afternoon.

“We’re just beginning to see the waters register on the flood gauge now; it’s going to come up pretty quickly,” Ms Strelow said.

“We’re going to really notice that with this one, it’s quicker moving, compared to some others [floods in Rockhampton] we’ve experienced.”

Disaster management groups will meet again today to reassess flood level predictions.

“We’re still thinking somewhere between 9 metres to 9.4 metres, and we are expecting on that higher end … I don’t want to underplay it,” Ms Strelow said.

“A lot of people won’t evacuate, people make their own decisions about what they’re going to do.

“Most people in those low-lying areas are experienced and know when to leave.”

An the evacuation centre at the Rockhampton Showgrounds will be open 24 hours a day throughout the week, and the first residents arrived there on Sunday night.

Long-time Rockhampton local Michael Portch said the community was resilient and knew how to prepare for and recover from floods.

“We’ve had half a dozen floods here in [Rockhampton suburb] Depot Hill, and I’ve been living here for 30 years,” he said.

The most recent were in 2015 after Cyclone Marcia and in 2013 after Cyclone Oswald.

Mr Portch said he expected a metre of water to go through the bottom level of his home.

“We’ll be waist deep in water [later in the week], so you go through and take all your furniture, put [it] all up and put it on the verandah,” he said.

“With any luck it’ll come up and drop down pretty quick, and we’ll just get into the clean-up and get it over and done with.

“It’s just a part of life, isn’t it? Around here it is.”

– ABC