SYDNEY - Australians living in western and southern parts of New South Wales state are bracing themselves for another bout of heavy rainfall this week, as emergency services issue alerts about worsening floods in the region.

Continuous downpours this month have already seen the area inundated with water, and some towns are expected to remain isolated for days, according to the State Emergency Service.

As more rain looms from Monday, the authorities have warned of prolonged or renewed flooding - cautioning travellers not to drive through floodwaters after police on Saturday confirmed the death of a child who was trapped in a vehicle that was swept away.

"We are conducting numerous resupply operations to residents with essential stores such as water, food and medicines and have deployed aircraft and high clearance vehicles," a spokesman for the emergency service said on Sunday. "Ongoing operational activity can be expected to continue in these areas."

The service has carried out 59 flood rescues in the past 12 days and has responded to more than 800 requests for assistance.

Australia's Bureau of Meteorology earlier this month declared a third consecutive La Nina event, an atmospheric phenomenon that drives wetter-than-usual weather patterns in Australia.

Those conditions could spell an especially disastrous summer by the time the phenomenon reaches its peak in December and January. Much of the ground is still sodden across the east coast after the region was inundated during the most recent La Nina event earlier this year, meaning even a light sprinkle of rain has the potential to spark flooding.

At the time, tens of thousands of residents across northern New South Wales and Queensland had to seek refuge from floods, which flattened about 15,000 houses and killed more than 20 people.

Insurance claims for the event have soared past A$5 billion (S$4.7 billion) - the second costliest weather episode ever experienced in Australia.

BLOOMBERG