The Insurance Council of Australia says that more than 37,800 claims have been lodged to date, but it is still too early to pinpoint the overall cost.

However, the clean-up is underway as the state's mud army collects tonnes of flood-damaged items that continue to pile up outside homes and businesses.

"It's clear that the flooding disaster emergency here in the southeast is not over yet, but the recovery process has begun," Deputy Premier Steven Miles said on Wednesday.

"Early estimates suggest that the damage bill for this disaster could be up to a billion dollars."

Urgent repairs are already underway on the state's public transport network which effectively ground to a halt as the water rose.

From Thursday, train services will resume at reduced capacity, transport Minister Mark Bailey said.

"There have been some really severe impacts across every line," Mr Bailey said.

"But what we'll be doing tomorrow is reopening the train system in a reduced format ... it's the best we can do at this point."

Public transport will also be free and tolls scrapped until Sunday night.

As floodwaters slowly begin to recede, volunteers are racing against mother nature with potentially severe storms forecast to batter the southeast in coming days.

More than 8000 volunteers have signed on to help with the massive relief and recovery effort underway across the southeast.

Claim numbers at insurer Suncorp have already topped 13,000 with the figure expected to continue to rise.

"That's an extraordinary number of claims in a very short period of time," Suncorp CEO Steve Johnston said.

Mr Johnston said it was already clear the state would be dealing with "large losses" and urged the recovery to "build it back better".

"The inevitability here is that we are going to be repairing homes that have been repaired three or four times."

While Gympie is still focused on its clean up, mayor Glen Hartwig said there will need to be a shift toward longer-term recovery for local businesses.

"There's a desperate need to show some care and compassion to these individuals who often will mortgage a kidney just to get involved and have a bit of an entrepreneurial go at life," he said on Wednesday.

"It's quite likely that a lot won't get back into Mary street, so in the coming time, we'll be talking with all the relevant people to see what can be done to assist them.

"They're good people, they're hardworking people, they love the region and they love the community and we want to see them thrive."

Brisbane City Council has launched a citywide clean-up while counting the cost but warns it will take time.

"It is still too early to determine the damage figure - there's a lot of assets that we haven't been able to get onto yet," Brisbane Mayor Adrian Schrinner said.

"Ferry terminals, river walks - there're a lot of parks that have had significant damage so this will take some time to get the figures together."

Cr Schrinner said the cost is not expected to exceed 2011 figures.

"I don't expect that it will be at that level. I think it will be less than 2011 but we still don't have a figure at this point. This will be something that takes time."

Australian Associated Press