Water levels remain at dangerous levels in the central Queensland city, just shy of Fitzroy River's 9.2 metre peak on Wednesday.
About 200-300 homes and businesses are inundated and 3000 properties have been affected by water.
The river is expected to remain above the major flood level of 8.5 metres for about a week.
Mayor Brad Carter said it's unknown at this stage how many homes will remain inundated for an extended period, but he said it's not looking hopeful.
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"The water is only going to drop 700mm," Mr Carter told AAP.
"That's not a lot of movement."
Mr Carter said a handful of stubborn residents had refused to evacuate, and some were now demanding food drops.
But he warned they could be on their own, and emergency services personnel would not risk their own lives to deliver help.
"If these residents want to stay in their homes - that's their decision, we won't force them out," he said on Thursday.
"However, we want to remind them that the water level will be high for more than one week after the peak yesterday, and we will not be able to resupply them."
He expressed frustration that even parents with children had ignored warnings to get out, branding them irresponsible.
The Queensland Police Service said officers are aware of the people in Rockhampton who have refused to evacuate, but fortunately they are the minority.
"The people of Rocky are well-informed and prepared for the floodwaters inundating their community and many people heeded warnings and self-evacuated," a police spokeswoman told AAP.
Residents in flood-affected areas are expected to wait another two weeks to start moving back into their homes.
About 130 are camped out at the evacuation centre, and a further 380 or so are staying with friends and family.
Mr Carter said anyone in need of essential supplies should move to the evacuation centre, at the city's Central Queensland University campus.
About 20 tonnes of non-perishable essential grocery items had reached the city in recent days, and more supplies were on the way.
The recovery and clean-up won't start until waters recede and it's a process that could take years, Mr Carter said.
Meanwhile, severe storms are forecast to roll over central Queensland on Thursday evening.
The weather bureau said they'll be watching closely overnight to see how it will affect Rockhampton.
"We're not expecting particularly heavy falls in the area," the bureau's David Woodman told AAP.
He said the effect on the Fitzroy River won't be known until the rainfall hits the ground.
"It's not expected to be a quick response to the flood," he said.
