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Flash floods hit Nelson and New Plymouth today, sparking scores of emergency calls, sending knee-deep rainwater through residences, and washing a BMW out to sea.
The MetService recorded a total of 98mm of rain fell in Nelson in the 24 hours to 9am today.
Forecaster Oliver Druce said 53mm had fallen in one hour between 8am and 9am.
"That's pretty extreme," he said.
"Fortunately it was just for the one hour, some other major floods in the past have been at that level sustained over several hours."
Nelson deputy chief fire officer Tim Bennion said the fire service had attended 70 calls this morning.
Extra staff had been called in, and volunteer brigades from Richmond had assisted.
Eight appliances went directly from property to property, pumping out water, he said.
"It was mainly surface flooding, some of it knee deep," he said.
"The majority was affecting low lying garages and basements."
Mr Bennion said he was not aware of any property suffering major damage.
Nelson City Council divisional infrastructure manager Fraser Galloway said fire and clean up crews had done an excellent job since this morning.
A few road slips had been cleared, and stabilisation work would begin in one or two areas tomorrow.
The downpour overwhelmed the city's sewerage system and some had been discharged to the sea, Mr Galloway said.
A warning had been issued advising people not to gather shellfish or swim in the Waimea Estuary until further notice.
Stoke was hardest hit, with Nayland College, Nayland Primary School and Broadgreen School closed today because of the flooding.
In New Plymouth, 36mm had fallen this morning, with higher readings around the district, including 68mm on Mt Taranaki and 100mm at Dawson Falls.
In New Plymouth, fire crews responded to around half a dozen call outs, after a heavy downpour around 11am.
New Plymouth fire senior station officer Ian Drewery said many houses suffered flooding after leaf-clogged drains overflowed.
Several rivers and streams threatened to break their banks, and in Hall Terrace, in Oakura, a BMW was washed into the Oakura River and out to sea.
Other than the loss of the car, Mr Drewery said he was not aware of much major damage. A ceiling had collapsed at one downtown building, but fire crews had not been called to assist.
"Our residents are pretty resilient.
"This was just a flash weather event which was over in less than an hour," he said.
The MetService said the rain band would have moved over the east coast and away from New Zealand by this evening.
- NZPA
