Provincial disaster and emergency officials in Papua New Guinea say there are fears water supplies are running dry and water-borne diseases are rising.
More than 30,000 people in Central Province are badly affected after continuous heavy rain last month flooded several rivers.
The Coordinator of the Central Province Disaster Centre, Daniel Mona, says contingency plans are in place to deal with problems that are arising from the damage to houses, schools and food gardens.
He says the biggest need is drinking water, water containers, and alternative sources of water.
"We are grading our health facilities to ensure that all health facilities are running to attend to any water borne diseases that may come. We've also collected samples and we've found that most of the water is all contaminated. We will have possibility of typhoid outbreak and all these things out in the local areas. So what we're looking at is how we can sustain good clean water, also some relief supplies for people to have access to."
Daniel Mona says authorities are also seeking support to repair damaged roads, bridges, culverts and schools.