A Grey Lynn home has been evacuated after it partly subsided during heavy rain this morning.
It was initially thought that the overnight rain had put pressure on a sewage drain and forced it to collapse about 3am, Fire Service shift manager Scott Osmond said.
However, a spokeswoman for Watercare later said there was no burst pipes under the woman's house.
The spokeswoman said a stormwater drain that runs under her home had overflowed during the night but it had not been the cause of the ground movement.
"The affected property connects to a combined stormwater and wastewater pipe. When this pipe became blocked with debris during the heavy downpour, it caused the stormwater and wastewater to back up and discharge through the affected property's gully trap. This affected the property's basement," the spokeswoman said.
Some areas of Auckland have also reportedly flooded because of the rain, with surface flooding on Mayoral Drive.
Emergency services were called to about 15 jobs between Northland and Auckland overnight as rain drenched the region.
Mr Osmond said most callouts were about trees that had fallen.
Federated Farmers Bay of Plenty president John Scrimgeour told Radio New Zealand today there had been constant rain at his property overnight.
Mr Scrimgeour said he had already received 50mm while other farmers had only received about 15mm.
"We're very grateful. It's been falling steadily overnight, sometimes a bit heavier than other times," he said.
"Some places ... are really looking forward to continuing rain throughout the day.
"[Summer has] been a real struggle for farmers so they're delighted to at last get a good soaking.
"In an ideal world a bit of rain every week would be great but we'll take whatever comes."
Experts expect the rain this week will bring relief to drought-stricken farmers.
Gusts of up to 90km/h buffeted Northland yesterday as the sub-tropical low from the north Tasman Sea began to move over the country.
The largest falls were at Kerikeri with 62mm and Kaikohe with 40mm, while several other places received 20-30mm, MetService forecaster Oliver Druce said.
He said it was "still early days" for most of the country still gripped by drought following one of the driest summers in more than 50 years.
A heavy rainfall warning is in place for Coromandel Peninsula, Bay of Plenty and Nelson, where up to 160mm is expected to fall.
"People in these areas are advised rivers and streams may rise rapidly, slips and surface flooding are possible," MetService said.
The rainfall since yesterday afternoon had been the longest stretch of wet weather for Auckland this year, WeatherWatch.co.nz analyst Philip Duncan said.
Winds are expected to reach 80km/h in exposed areas of the city today.
Mr Duncan said blocked drains could cause surface flooding in some areas.
He said the centre of the low was expected to make landfall near Taranaki tonight, "bringing more rain and gusty winds".
As it moves west overnight it will push heavy rain to the South Island, he said.
"There's very little doubt in my mind that a number of droughts are coming to an end and the good news is we are expecting some decent downpours along the eastern coastline too," Mr Duncan said.