Major flooding continues in the Gympie, Maryborough and Sunshine Coast regions after widespread rainfall saturated the area with totals of 200-600 millimetres recorded in the past four days.

Up to 3600 homes in Gympie could be affected by the rainfall as some isolated areas of the region received more than 1000mm over the period.

The Mary River at Gympie is at 20.31 metres and falling with major flooding, but may drop below the major flood level of 17 metres on Monday evening.

In Maryborough, business operators have bunkered down at home as flooding on the Mary River has inundated pedestrian bridges linked to the CBD.

"Everyone's pretty much reluctantly settling into the fact that we're going to go through it again. There's not much we can do about it," Doug Cuzens from the Maryborough Services Memorial Bowls club told AAP.

"Where I am at the moment I can't get out because Schultz's bridge has gone under. It's running over the top of the bridge.

"We're all optimistic. Hopefully we don't go getting an 11-metre flood or an 11-and-a-half metre flood that people think could possibly happen, but you just don't know."

The town's levee is withholding the Mary River at 9.8 metres, but Fraser Coast Mayor George Seymour said that was expected to increase later on Monday.

"Right now it's at 9.8 metres and maybe in about 10 hours or less, it will be at 10.7 and perhaps even higher," he told AAP.

The Bureau of Meteorology estimates the flood peak in Maryborough will be similar to that observed during Tropical Cyclone Oswald in 2013.

Mr Seymour said CBD businesses should be safe as the levee protects up to 11.3m, but many residences would be affected if it gets above 10.7m.

It is the second time in six weeks the town on the Fraser Coast has erected its flood levee after catastrophic flooding forced an evacuation of the CBD in January with as many as 100 businesses affected.

To the south, and Sunshine Coast Council Mayor Mark Jamieson said residents were well into the recovery stage as the area received more than 1000mm of rainfall in the past week.

In the 24 hours to 9am Sunday, rainfall totals of 150-350mm were recorded in the Noosa and Maroochy catchments, with a further 20-100mm observed since.

Mr Jamieson said there was significant damage to roads in the hinterland area with council staff investigating damage to roads, bridges, sea walls, weirs and community facilities.

He said the number of interstate travellers left stranded on the Sunshine Coast was dwindling as the region's airport was operational again.

But Mr Jamieson said the Sunshine Coast, like large parts of the southeast, would need plenty of recovery assistance.

"The funding that will be required through the federal and state governments will run into the many, many tens of millions of dollars," he told AAP.

On Monday, the federal government announced disaster payments for adults and children accessible through the same services used throughout the COVID-19 pandemic.

"Our payments are $1000 per eligible adult and $400 per eligible child, and that is available through Services Australia Disaster Assistance Phone Line," Prime Minister Scott Morrison said on Monday.

Australian Associated Press