It comes after Australian authorities on Friday confirmed two citizens had made contact overnight, bringing the number of missing Australians to 36.
As the search for the remaining survivors continues, Australian Red Cross head of migration Nicole Batch said infrastructure damage was posing a major challenge.
Interruptions to mobile networks, intermittent power and collapsed bridges and roads meant fewer opportunities to make contact, added to a surge in demand.
"The collapse of bridges, the poor road access - all of these elements will be making it difficult for people to travel quickly," Ms Batch said.
"The scale of the disaster and the number of people that are trying to make contact - that is one challenge in itself."
Ms Batch, who specialises in locating missing people following disasters, said reaching loved ones was almost always the first thing survivors tried to do.
But many likely lost their phones during the floods or else were limited in their ability to use them due to power or mobile network blackouts.
State-owned provider Nepal Telecom announced on Thursday services had been fully restored to disaster-hit regions, after being progressively brought back online.
But it followed days of coverage challenges and ongoing capacity strain, added to more immediate infrastructure roadblocks.
It comes as rescue efforts continue for the hundreds of workers feared trapped in underground power stations damaged or obscured by the floods.
Melbourne-based engineer and geologist Arnold Dix, who is advising Nepalese authorities on the rescues, said there was no test case for their work.
"It's like solving a puzzle you can't see."
He is advising on the Trishuli 3A hydropower project, where rescuers reportedly pulled two workers alive from a tunnel on Friday, nine days after the floods began.
The rescues have been reported on local television news channels and by Nepalese lawmaker Shri Ram Neupane on Facebook, AP reported.
Speaking hours before the reports surfaced, Mr Dix told AAP he had received word members of the Nepali army had heard voices inside the tunnel.
"When you're exhausted, sometimes your mind plays trick on you ... but once rescuers hear there might be someone alive ... this spurs you on," he said.
More than 1200 people have died and 5000 are missing since a glacier collapse brought flash flooding to towns and valleys along the border region.
The federal government has sent 19 officials and disaster response specialists to the region, with another 23 to be deployed within days.
Prime Minister Anthony Albanese spoke with his Nepalese counterpart on Friday, offering Australia's deepest condolences. "The loss of life and destruction is devastating, and we will keep doing everything we can to find the Australians still unaccounted for," he wrote on X.
On Thursday, Foreign Minister Penny Wong confirmed local authorities would conduct searches in areas where many Australians were believed to have been staying.
Rescue teams from the Nepali army were expected to search those target areas identified by Australia on foot, with helicopter and drone support.
DFAT is working with local authorities to establish the whereabouts and welfare of affected Australians and to contact next of kin where appropriate.
Aid supplies aboard a Royal Australian Air Force plane arrived in Kathmandu on Wednesday.
More than 1400 hygiene kits, 2200 solar lights and phone chargers were among the items.
Australians have donated more than $4 million to the Emergency Action Alliance to support recovery efforts.
The federal government will provide a further $3 million to match public donations, bringing the ongoing humanitarian support package to a total of $11 million.
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