East Coast flooding: Rain to fall for days, but the worst is over, forecasters say

Rain will continue for days on the sodden East Coast, but the worst of the downpour is over, forecasters say.

Hawke's Bay and Tai Rāwhiti were slammed with torrential rain on Tuesday night and Wednesday.

More than 400 properties in Wairoa were inundated and roads in and out of the town were flooded, restricting access.

States of emergency remained in place there and in Heretaunga on Wednesday evening.

Minister for Emergency Management and Recovery Mark Mitchell called the scale of the floods "catastrophic".

Orange heavy rain warnings for Hawke's Bay, both north and south of State Highway 5, would be lifted at 11pm Wednesday, MetService said.

"Further periods of rain or showers are forecast through until Friday, but amounts are expected to be well below warning criteria."

MetService meteorologist John Law said the low pressure system that caused the torrential rain would stay "close by" on Thursday,

"(It) continues to feed some showers or spells of rain in towards that eastern coast, but generally not as intense as it was last night, and the winds are a little better as well."

It would "move slowly further away" throughout Thursday.

Any weather impacts would be "not nearly to the same scale as we saw over the last few days", Law said.

The weather for the rest of the country would be quite settled throughout Thursday, bar some showers in Wairarapa and "patchy rain" in Fiordland, Westland and Southland, Law said.

Skies would be overcast in Hawke's Bay on Friday but the threat would have passed, he said.

"We're going to find still more cloud around that eastern coast but the rainfall should ease off."

Hawke's Bay Civil Defence Emergency Management said it would "continue to monitor and engage with this weather event overnight" heading into Thursday.

Many residents of the coastal community of Haumoana would spend a second night away from their homes due to concerns the high tide would bring large swells.

One hundred and forty homes were evacuated, with most staying with friends and family, and 44 people were registered at the Haumoana School Hall.

In Wairoa, schools were being urged to stay closed on Thursday, and people asked to stay home - and away from potentially contaminated floodwaters - if possible.

Mayor Craig Little said the flooding was "devastating" and Wairoa had been cut off again.

"This flooding event took place on the southern side of town closer to the Wairoa River mouth, as opposed to the Cyclone Gabrielle flooding 16 months ago which affected the northern side of town when 350 homes flooded, and 120 businesses were impacted," Little said.

"This type of flooding has never been seen before and there appears to be a direct correlation between the flooding and the status of the Wairoa River mouth.

"This event is devastating for our isolated community which has still not recovered from Cyclone Gabrielle. We have once again been cut off by road which can leave us feeling very alone."

He said he was not sure how the town was going to get through the latest weather onslaught.

His immediate priority was ensuring the people of Wairoa were safe, he said.

Gisborne mayor Rehette Stoltz said it was a "dark time in Tai Rāwhiti", coinciding with the deaths of three local fishermen.

"People are really sad and stressed because we are not only dealing with weather, we are also dealing with a community in mourning."

Twenty-seven local roads were still closed on Wednesday evening, she said, with Waka Kotahi working to reopen them.

However, high winds had slowed those efforts, as well as those of power crews.

MetService said gusts of over 100km/h were recorded on Wednesday.

"We are cut off," Stoltz said.

"Lots of electricity lost to lots of homes. Heaps have been restored. Lots of surface flooding, trees down ... just everything going at once."

Authorities would have a "better understanding of what is ahead of us and what our recovery looks like" in the coming days, after the rain had stopped, Stoltz said.