More than 550 properties in northern NSW have been issued with a flood evacuation warning after heavy rain
Emergency services are preparing to evacuate hundreds of homes in Moree, with the north-western NSW town predicted to be split in half by floodwaters later in the day.
'We think this is going to be bigger than the floods that occurred in the 1970s,' NSW SES Deputy Commissioner of Operations Steven Pearce told AAP on Thursday.
'The town will be cut in two.'
Severe downpours of 125 millimetres hit the town overnight, causing the Mehi and Gwydir rivers to break their banks.
About 450 properties are being affected by the swollen Mehi River, which is set to reach 7.5 metres on Thursday morning and rise to 9.5m by 3pm (AEDT), the Bureau of Meteorology (BoM) predicts.
The river is then expected to peak near 10.3m on Friday morning.
Evacuation warnings in place for much of the town are likely to be upgraded to compulsory orders later on Thursday.
'We have got to do some more planning before we can evacuate, it's going to get really tough with the town cut in two,' Mr Pearce said.
Moree Plains Shire Mayor Katrina Humphries said the rain had been relentless and it was about to get 'a whole lot tougher'.
'We are only six weeks out from the last floods so the ground is sodden,' Ms Humphries told ABC Radio on Thursday.
'All the billabongs, all the creeks, all the gullies are already full and there's nowhere for this water to go except up.
'This is going to be the Big Kahuna.'
In the mid-north coast and northwest areas of the state, about 2500 people are now isolated by floodwaters. The SES is concerned the situation will get worse as heavy downpours overnight put pressure on swelling river systems.
Helicopters are hard at work making food and medical drops as well as moving livestock.
Emergency services rescued a truck driver from his semi after it was caught in rising waters near Gunnedah.
Evacuation orders have also been issued overnight for parts of the Wingham Peninsula, Barraba and Taree.
More than 60 properties are at risk on the Wingham Peninsula, where residents have been warned to expect flooding in low-lying areas on Thursday.
The BoM said the river at Wingham had reached 8.9m in the early hours of Thursday morning.
In Taree, where 40 properties are affected and the SES is setting up evacuation centres at Taree PCYC and Taree High School.
The BoM has predicted flood levels for the Taree Bridge Gauge to hit 2.4m at 8am (AEDT) on Thursday.
Meanwhile in Barraba, the Manilla River reached 5.7m on Thursday morning.
Nineteen properties have been issued with an evacuation warning, with the SES reminding people not to walk, ride or drive through floodwaters.
Thirteen flood warnings remain in place for river systems across the state.
The SES is urging all locals in flood evacuation warning areas to monitor the situation and be prepared to evacuate.
