A storm that battered lower Northland, particularly around Mangawhai, in February has cost more than $20 million in insurance claims.

The foul weather, which included a weather bomb on February 24, caused widespread flooding and slips in and around Mangawhai in particular. The town was isolated for part of the day and following morning.

The weather event ran from February 21 to 28.

The Insurance Council of NZ said it had accepted claims totalling $20.8 million, the majority in Northland.

It was the third bout of atrocious weather within a month to lash Northland.

On February 24, a front became stalled across Auckland and southern Northland. Converging winds associated with this feature, as well as an upper-level low-pressure system, allowed it to become the focal point of widespread heavy rain and thunderstorms. Early in the afternoon, a thunderstorm led to intense downpours near Mangawhai, leading to flooding, road closures, and serious property damage.

The bout of severe weather doused Mangawhai with nearly 400mm of rainfall in less than half a day.

A Northland Regional Council rain gauge “Hakaru at Tara” recorded a 24-hour rainfall total of 380mm between the morning of February 25 and the next morning – more than 670 per cent of the February normal in nearby Mangawhai.

It was the third storm in less than a month to batter parts of Northland and cause widespread damage.

Insurers have so far paid out $1.08 billion of an estimated $3.18b over 107,569 claims arising from the twin climate disasters of the Auckland Anniversary Weekend floods and Cyclone Gabrielle from February 5 to 11, many of the claims from Northland. However, the Insurance Council of NZ does not break down what total was claimed in Northland.

For context, the general insurance sector incurred total claims of $3.08b in 2022, while claims for 2016′s Kaikoura earthquake totalled $2.27b.

“While we are pleased that good progress is being made, with 35 per cent of claims already fully settled (34 per cent by $ value), we said in February that many of the more complex claims would take many months, and some over a year or more, to complete,” Insurance Council of New Zealand Te Kāhui Inihua o Aotearoa (ICNZ) chief executive Tim Grafton said.

In addition to paying out more than $1b, insurers had bought in hundreds of extra staff since the events and been working with councils, in communities and with individual customers to help them get back on their feet.