New Zealand insurers face an influx of claims after the remains of Cyclone Debbie crossed the Tasman, bringing heavy rainfall and flooding.

The National Institute of Water and Atmospheric Research (NIWA) says a “tropical torrent” produced up to triple the normal April rainfall in just three days at some locations.

“Claims have already come in down the length of the country,” Insurance Council of New Zealand CEO Tim Grafton told insuranceNEWS.com.au. “It is too early to tell what the number of claims and the costs will be, but from the indications we already have this is going to be a big storm event.”

Edgecumbe in the North Island was evacuated after the Rangitaiki River burst a levee, flooding hundreds of homes, with losses likely to run into millions of dollars.

The Auckland suburb of Mangere recorded its normal April rainfall in just 14 hours, Wellington airport had its wettest day since 2008 and landslips closed roads near the South Island town of Kaikoura, which was hit by a 7.8-magnitude earthquake in November.

New Zealand has suffered a slew of bad weather recently, but the latest event was “significantly worse” than other storms in the past two or three years, Mr Grafton says.

NIWA forecaster Ben Noll says the country was caught in a pattern of pressure systems that favoured wet weather, with the possibility of further heavy rainfall this month.

Rain from Cyclone Debbie followed a “Tasman Tempest” last month that brought more rain to Auckland in a few days than typically falls in all of March, according to NIWA.