Anthony Albanese has visited central western NSW to see for himself the devastation caused by flooding as affected communities nervously wait for water levels to peak.
The prime minister joined Premier Dominic Perrottet in Eugowra on Tuesday, where hundreds were evacuated last week after a flash flood swept through, destroying houses and gutting shops.
The water rose so quickly 159 people - one-in-three residents - had to be rescued either by helicopter or boat.
During the visit, grants of up to $50,000 were announced for impacted businesses and non-profits to be jointly funded by the state and Commonwealth.
In addition, 46 local government areas will receive $1 million to help with the recovery effort and grants available for primary producers have been increased to $75,000.
Individuals and families are also eligible for a one-off payment of $1000 for every adult and an additional $400 for each child.
"We're providing what support we can to people at this time," Mr Albanese said.
National Farmers Federation president Fiona Simson welcomed the help but stressed a serious issue remained with ruined roadways.
"We're talking about billions of dollars worth of damage in NSW alone," she said.
"It's critical that people who can harvest their crops do and it's critical that they can get that produce from their farm to the silos or to the processing facilities."
Governments should be working together to reconnect key trade routes ahead of the summer harvest, including rolling out ADF personnel to get the job done.
"Whether it takes bringing in the army ... we're saying do whatever is necessary," Ms Simson said.
An SES spokesperson told AAP the ADF had so far not been assigned to help rebuild roads in the central west.
However Regional Roads Minister Sam Farraway said 200 contractors and workers from Transport for NSW would be deployed there and in the Riverina to help reconnect the network.
"Early estimates from councils indicate 10,000 kilometres of roads have been affected, which will take many months to repair," he said.
Mr Albanese said all levels of government were co-operating to provide as much assistance as possible.
Later, in parliament, he addressed communities affected by "repeated, relentless flooding".
"The whole of Australia feels for you," he said.
Mr Perrottet vowed to work with the prime minister and premiers to develop national legislation to ensure rebuilding happens in a way that doesn't further endanger lives and property.
"Almost every community across NSW right now is at risk of flood," he said.
"We can't in many circumstances unwind the past but we cannot make those mistakes going forward."
The SES is continuing preparations along the Lachlan River at Euabalong and Edward River at Deniliquin, with sandbagging, resupply and evacuation help.
The immediate response is also focused on Forbes, Condobolin and Eugowra, Walgett and Bourke in the northwest, and south to Hay, Albury, Echuca, Mildura and Wentworth.
The Riverina town of Moulamein is isolated and its 500 residents were urged to evacuate under escort on Tuesday afternoon or face being stranded for weeks.
SES Assistant Commissioner Dean Storey said numerous inland roads were cut off.
"We are seeing roads affected by floodwaters on the Murray, Murrumbidgee and Lachlan rivers in the state's southwest, and the Bogan, Macquarie and Darling Rivers in the north and west," he said.
He also warned against driving in floodwaters in what has become a repeated safety message.
"The major cause of death during floods is a result of people driving, riding or walking through floodwaters".
Major flooding is still occurring at Condobolin and Euabalong where the Lachlan may peak at eight metres by Thursday - higher than the 1952 floods.