Major flood levels in the twin-towns of Echuca and Moama on the Victoria-New South Wales border have exceeded the 1993 record of 94.77 metres above sea level.
The Murray River reached 94.79 metres in the area at 5pm with the Bureau of Meteorology (BOM) expecting it to reach 95m overnight Sunday and into Monday.
Murray River Council Mayor Chris Bilkey said on Friday he was confident Moama's levee, which was built after the 1993 floods and had not been tested since, would hold.
"There are outlying areas to the east of Moama that are already inundated, and they always would be in a flood of this sort," he said.
"But the expectation is that it will hold for a majority of the town."
'Sandbagging the state'
Meanwhile, NSW authorities have renewed concerns for the Northern Rivers community amid predictions of an intense weather system forming in Queensland, expected to reach the area over Sunday and Monday.
Emergency Services Minister Steph Cooke said BOM predicted possible major flooding for Lismore and resources were being flown into the area to help.
"We are quite literally sandbagging the state at present," she said.
"We have dispatched over 500,000 sandbags to communities like Moama and across NSW over the last two and a half weeks, they're going out the door at a rate of 30,000 a day."
In the state's north-west, Gunnedah residents have been told to evacuate this afternoon.
More residents in Moree have also been ordered to evacuate after 4,000 locals were warned to leave their homes last night.
Emergency Services have warned the town's Mehi River could reach the 1955 flood record, which inundated 800 homes and most CBD businesses.
Moree Plains Shire Council Mayor Mark Johnson said this flood could affect the same number of houses but it was a "different situation".
"We haven't experienced this type of flood for many many years, not since 1955," he said.
"It will go places that we don't even expect."
A few hours south in the village of Carroll — east of Gunnedah — residents were told to evacuate this afternoon.
The SES has warned locals in the regional communities of Wee Waa, Toomelah and the Upper Macleay to prepare for isolation.
On Saturday evening an additional 12 Local Government Areas (LGAs) were given natural disaster status, making them eligible for financial assistance.
Help is now available for residents in the Albury, Berrigan, Carrathool, Cobar, Federation, Griffith, Hay, Leeton, Murray River, Murrumbidgee, Narrandera and Wagga Wagga LGAs.
A total of 43 LGAs are now subject to natural disaster declarations across NSW.
"We are continuing to assess the impacts of this flood event as quickly as possible, with disaster declarations like these the crucial first step in unlocking assistance for those in need," Ms Cooke said.
More rain on the way
The SES said ongoing wet weather was likely to exacerbate and renew flooding in parts of NSW in the coming days, moving some from minor to major flooding status.
Helen Reid from the Bureau of Meteorology said Saturday would bring more rainfall to flood-affected areas of the New England and north-west regions.
"Some of that will be in the form of thunderstorms which may also bring some heavy rainfall with them, which could lead to not just extra riverine flooding but some flash flooding as well," she said.
She said conditions could ease towards the middle of next week.