Large parts of Queensland are on severe weather alert as ex-Cyclone Oswald continues to dump torrential rain.
Torrential rain continues to hit communities in the state's central and northern regions, isolating towns and flooding properties.
In Ingham, north of Townsville, the Herbert River peaked at midday at 12 metres after more than 200 millimetres of rain in the past 24 hours.
The town remains cut in half, but the road from Townsville to Ingham is open.
Water is also lapping at the doors of homes and businesses at nearby Halifax and Mayor Rodger Bow says Halifax and Lucinda are cut off.
Floodwaters could isolate the town of Agnes Water in central Queensland.
The road from Agnes Water to Gladstone is likely to be closed and the route south to Bundaberg is also flooding in sections.
The Bruce Highway just south of Rockhampton is closed and the Capricorn Highway to the west is cut.
Regional director of Emergency Management Queensland Wayne Heppell says authorities have also been involved in several swift water rescues where motorists have driven into floodwaters or have been trapped by rising water.
Vinord Anand from the Tropical Cyclone Warning Centre says there is a danger the cyclone could reform as it moves towards the south-east in the coming days.
"If it moves over the water there is a chance it could develop into a tropical cyclone," he said.
The State Emergency Service received more than 130 calls for help today, mostly from communities around Mackay and Rockhampton.
Dozens of calls related to flash flooding which was threatening to or had already inundated homes and businesses.
Communities from Townsville to Bundaberg have been warned that up to 600 millimetres of rain could fall over the next couple of days.
Forecaster Tony Auden says the system may strengthen.
"It is a fairly uncertain situation and I would encourage people to keep on top of forecasts over the next few days right through eastern Queensland," Mr Auden said.
Rail, roads cut
All rail services from Mackay to Cairns are out of action because of localised flooding over train tracks.
Queensland Rail says it is making preparations as the torrential rain moves south and will not restart northern services until conditions are safe.
Spokesman Jim Benstead says they are monitoring track conditions further south.
"We have moved a train and located the train at Mackay in case the services or the track is cut between Mackay and Townsville," he said.
"At least then we can get our customers that are travelling south - that are located at Mackay - able to get back to Brisbane."
Ergon Energy says it is preparing for further power outages after strong winds overnight left more than 6,000 properties without power in Cairns and Cooktown in the far north.
A spokesman says there could be similar problems further south over the next day or two.
Authorities say crocodiles are turning up in floodwaters along the Bruce Highway in north Queensland.
Ingham Police Sergeant Geoff Bormann says he photographed a 2 metre croc on the highway at Seymour River yesterday.
He says motorists who try to cross flooded roads and break down could find themselves staring at a croc.
"While we have been patrolling around we have seen a crocodile at Cattle Creek just south of Ingham which is another area that is prone to flooding and crossings," he said.
"When we get floodwaters it gets them more active and gives them an opportunity to cover more territory."
Central Queensland on alert
As the system moved south, Mackay was hit with up to 120 millimetres of rain this morning.
Mackay councillor Deirdre Comerford says an emergency centre has been opened as a precaution.
About 170mm of rain has fallen in Gladstone in the past 18 hours and Rockhampton has received about 120 millimetres.
Rockhampton is the latest centre to receive torrential downpours, with a rain band affecting a long stretch of the central Queensland and Fraser coasts this afternoon.
There have also been strong winds, with gusts of nearly 140kph at Hay Point, south of Mackay.
State Emergency Service controller Eddie Cowie says crews have been called to reports of flooding and roof damage in Rockhampton and Mount Morgan.
"We're working in very closely with Rockhampton Regional Council in how we can manage requests for sand bags," he said.
Authorities at Rockhampton say it is too early to tell if heavy rain will cause flooding in the Fitzroy River.
Deputy Mayor Tony Williams says the impact on the river depends on the amount of rain in catchment areas.
"Probably dependent on where the trough heads, whether it's heading out across the coast into the ocean or whether it stays inland," he said.
Authorities are also warning residents of flood-prone towns like Baffle Creek, Agnes Water and 1770 to prepare for several days of inundation.
Gladstone deputy mayor Matt Burnett says areas south to Bundaberg are particularly flood-prone.
"Possibly going to be making a bit of a havoc down our way, but we're just saying residents in that area, it is possible they could become isolated as they have in the past, so just to be ready for that," he said.
"Whether it means to be out of town at the time you need to sort of pack up and start getting yourselves organised now.
"No need to panic, just if people are worried about being isolated then perhaps they might need to make themselves move onto another area."
© ABC 2013
14:24 EDT Thunderstorms are due to develop daily across New South Wales and Queensland for almost two weeks.