UPDATE: THE Fraser Coast has officially been declared a disaster zone after heavy rainfall caused extensive flooding in Maryborough, Hervey Bay and outlying areas.
Granville, Pacific Haven, Burrum Heads and Aldershot are all isolated.
Fraser Coast mayor Gerard O'Connell said possible air support was an option as the council tried to keep the communities equipped with food and medical supplies.
He said Burrum Heads was of particular concern after a mini-tornado ripped through the community, causing extensive damage to homes and leaving some with minor injuries.
Cr O'Connell said the flooding of the Mary River was expected to peak at 9m but that was dependant on how much rain fell on the Fraser Coast.
EARLIER: The Burrum and District Community Centre at Howard has been opened as an evacuation centre for people, particularly from Pacific Haven.
Fraser Coast Mayor Gerard O'Connell said he believed there was already a family of five sheltering there.
EARLIER: Police, in conjunction with the Mayor, have asked for the Fraser Coast to be declared a disaster situation with communities isolated by flooding and Burrum Heads reeling after being hit by a mini-tornado.
Fraser Coast Mayor Gerard O'Connell said Aldershot and Pacific Haven were isolated by "really significant flooding".
"We just can't get to them at the moment," he said.
Cr O'Connell said the Lamington Bridge to Tinana had been closed and the Granville Bridge was about to be closed, isolating Granville.
"Already water has come across lower Kent St," he said.
Cr O'Connell advised residents to stay off the roads.
"If you don't need to be on the road, don't move," he said.
"If there's water across the road, stay out of it."
Cr O'Connell said there was a bit of a representation of police, ambulance and fire officers at Burrum Heads which was hit by a "tornado-type event" earlier on Sunday morning.
Roads to the coastal community are believed to be cut.
Cr O'Connell said the esplanade from Elizabeth to Hibiscus Sts in Urangan had been closed due to abormally high tides and winds and was expected to peak about 8.30-9am.
He warned people to stay out of the area.
Cr O'Connell said the Bruce Hwy was cut between Maryborough and Tiaro, also between Maryborough and Aldershot at Saltwater Creek; the Cooloola Coast Rd was also cut and the Maryborough-Hervey Bay Rd was blocked at Susan River.
He said the Mary River flood situation was being exacerbated by the continuing solid and intensive rain which was adding to the huge run-off.
"It's a two-pronged attack on us," Cr O'Connell said.
He said the businesses along the riverbanks at the marina were well-advanced in their preparations and had begun moving to higher ground on Saturday.