Hundreds of families on the South Island of New Zealand were forced to evacuate their homes on Thursday, August 18, after flooding in three regions prompted an emergency declaration.

A tropical cyclone has dumped over 30 centimeters of rain on portions of the South Island, forcing rivers to overflow. Extreme weather has also caused trees to fall, obstructing major routes.

In Buller, on the west coast, and Nelson, where 233 homes were evacuated after a month's worth of rain poured in 15 hours, a state of emergency was proclaimed on Wednesday.

The rainfall transformed Nelson's primary river, the Maitai, into a raging torrent, inundating homes, exposing pipes, and flooding streets to the knees.

Rachel Reese, the city's mayor, referred to the flash flooding as a "one-in-100-year event" as search and rescue teams and military troops assisted individuals in flooded streets.

She cautioned the community to treat all water tainted because some sewers had ruptured.

Sam Lagrutta, a resident of Nelson, described the scenario as "frightening" after police gave him only five minutes to evacuate his residence.

He told the New Zealand Herald that he grabbed a carry-on bag and stuffed it with his passport, wallet, and any other critical items he could find.

One hundred sixty additional households along the west coast of the South Island were also advised to leave.

Buller has been repeatedly impacted by water over the past few years.

Mayor Jamie Cleine stated that frequent evacuations had a negative impact on a town preparing for further flooding.

"It is extremely financially and mentally distressing for individuals. Until a long-term solution can be found, this is our reality "He stated on the website Stuff.

The Minister of Emergency Management, Kieran McAnulty, was scheduled to visit Nelson on Thursday with a further severe precipitation forecast.

As a result of a fallen tree on State Highway One in Northland, three individuals have been injured in a car collision on the North Island.

The wet winter continues after the wettest July on record in New Zealand.

Before the damage can be remedied, the largest insurer in New Zealand, IAG, has stated that construction in flood-prone areas must cease.

According to the insurer, climate change is significantly influencing the insurance industry since ten big floods in the past two years have resulted in total losses of over NZ$400 million (S$348 million).

Approximately 1% of New Zealand's dwellings, or 20,000 houses, are at risk of flooding.