The international aid agency Oxfam says the flooding situation in Papua New Guinea's East Sepik province has now reached crisis point.
Seven people have been confirmed dead and about 11,500 people have been affected by flooding along the Sepik River.
Phillippe Allen, Oxfam Australia's associate country director for PNG, says although flooding is a regular occurrence, water levels have risen excessively in this wet season.
He's told Radio Australia's communities that are normally dry for most of the year have been inundated, damaging water sources and destroying sustainable livelihoods.
"In the last six to twelve months, we've seen such a sustained heavy rainfall that the river level has risen about six metres now," he said.
"[That is] about three times higher than what it normally is.
"If we do see continued rainfall and, perhaps, even a rise of another metre over the next couple of months, we could see thousands more people affected."
The flood has given rise to fears of a disease outbreak, if hygiene conditions of water sources are not improved.
Communities defecate in the stagnant water around their houses that are also being used for drinking, washing and bathing purposes.
Oxfam says it plans to distribute hygiene kits, kitchen kits and shelter kits, as well as initiate a hygiene promotion campaign.
Another big risk is the lack of shelter for the affected communities, as houses are sinking due to the continuous inundation over the past few months.
Oxfam has also identified a long term need for the relocation of villages to safe high grounds.
"I think there's certainly a need for the government and the communities affected to talk about possibly the relocation of some of the villages which have been set up very, very close to the water bank," Mr Allen.
"Good practice dictates that you should allow for a few metres at least when you are constructing villages."
© ABC 2013
17:08 EDT A high pressure ridge cleared skies and a cool air mass created the perfect conditions for temperatures to drop well below the monthly average in parts of New South Wales.