AUCKLAND – The authorities in New Zealand’s biggest city, Auckland, began mopping up on Saturday after torrential rains brought flash flooding and evacuations, with at least three people confirmed dead and one still missing in the widespread inundation.

A state of emergency remained in place in the city of 1.6 million people on New Zealand’s north island as the rains eased after Friday’s flooding in the north, north-west and west.

Prime Minister Chris Hipkins, less than a week in office, flew by helicopter over Auckland before touring flood-hit homes.

“The level of devastation in some areas is considerable,” Mr Hipkins told reporters, describing the event as “unprecedented” in recent memory.

He confirmed three people died in the flooding, and at least one other person is missing.

“Having just surveyed some of the extensive damage both on the ground and in the air, it’s clear that it’s going to be a big cleanup job,” Mr Hipkins said at a press conference in Auckland after flying from Wellington on a Defence Force aircraft.

“The loss of life underscores just the sheer scale of this weather event and how quickly it turned tragic.”

Daylight revealed the impact of the storm, caused by warm air descending from the tropics, sparking heavy rain and thunderstorms, said Auckland Emergency Management, part of the city’s council.

“Auckland was clobbered on Friday – Auckland’s wettest day on record – and today we start the cleanup,” the agency’s duty controller, Mr Andrew Clark, said in a statement, urging caution for residents returning home to survey flood damage.

While heavy rain had eased, another period of downpours was possible on Sunday, the national weather forecaster said.

Showers were “dotted around Auckland” with some heavy rain west of the city, Auckland Emergency Management tweeted, while warning residents to “stay safe” amid the emergency.

“We’re not out of this yet. Heavy rain returns tomorrow,” the agency wrote on Twitter.

The police said on Saturday that the bodies of two men were found in floodwaters in separate locations in a northern suburb.

A third person died after a landslide brought down a house near the city centre while a fourth individual is still missing after they were swept away in a community south of Auckland, the police said.

More than 2,000 calls for assistance and 70 evacuations were made around the city, the New Zealand Herald reported.

City rainfall records were broken, with Auckland Airport logging 249mm in the 24 hours to 9am on Saturday, beating the 1985 high of 161.8mm.

Some local flights resumed at Auckland Airport on Saturday afternoon, which closed domestic and international operations on Friday.

Air New Zealand said it is unable to resume international flights from Auckland until noon on Sunday because of significant damage to ticketing, baggage and processing equipment.

The international terminal stayed closed on Saturday, with no departures likely to take place before 5am on Sunday and no arrivals until 7am.

“We know from midday that airport and airline operations will be back up and running, and we’ll be restarting with around three flights an hour as we ease into it,” Air New Zealand chief operational integrity and safety officer David Morgan said. “For context, we usually operate around 13 baggage belts, but with the damage we could be down to as few as three.”

“Certainly the airport has never been tested in this way before,” said Ms Carrie Hurihanganui, chief executive at Auckland Airport. “Our assessment is we need more time to make sure it is all working well and, more importantly, safely, before we resume international operations.”

She apologised for the “extraordinary disruption and discomfort” suffered by at least 2,000 travellers left stranded in the airport’s flooded buildings until the early hours of Saturday.

Some passengers who had already boarded a plane when the storm struck remained on the grounded aircraft for hours.

On Friday, social media showed firefighters, police and defence force staff rescuing stranded people from flooded homes using ropes and rescue boats.

The flooding forced cancellations of British pop star Elton John’s concerts in the city, which were scheduled for Friday and Saturday nights. REUTERS