Wild weather is sweeping through the east and lower North Island and some parts of the South Island, with red and orange weather warnings in force for heavy rain and strong winds.
In some places, MetService forecasters have warned there is a threat to life from dangerous river conditions, significant flooding and slips.
States of emergency have been issued for the Tararua District, Waipā District and Ōtorohanga District.
This latest burst of bad weather comes as several regions reel from severe storms that have already closed roads, flooded properties and damaged infrastructure.
Heavy rain and severe gales are forecast to batter the eastern and southern North Island, parts of Marlborough and North Canterbury in the South Island, as well as the Chatham Islands.
In the North Island, MetService has issued a red heavy rain warning - the highest alert level - for parts of Manawatu and Ruapehu districts, as well as multiple orange heavy rain and strong wind warnings today about dangerous conditions from this morning through to Monday evening.
Emergency Management in the Manawatū-Whanganui region warned there was likely to be flooding and landslips.
The council's spokesperson, Chay Hook, said people living in a warning area that regularly floods should be prepared to leave before waters rise and not wait for official evacuation orders.
Heavy rain warnings in place
A red heavy rain warning will be in place at Manawatu, Rangitikei and Ruapehu Districts north of Feilding and east of State Highway 1 from 6pm today until 2pm tomorrow.
The regions are expected to experience 140 to 180mm of rain with peak rates of 10 to 20 mm per hour tonight and tomorrow morning.
An orange heavy rain warning is in force for Gisborne/Tai Rāwhiti south of Poverty Bay and Hawke's Bay, about and east of Wairoa, from 2pm on Sunday until 5am on Monday, with 90 to 140mm forecast and peak intensities of 20 to 30mm an hour overnight.
There is a moderate chance of an upgrade to red.
Between 100mm and 150mm of rain is forecast, with peak intensities of 20 to 30mm per hour tonight and on Monday morning.
Further south, Hawke's Bay south of Waipukurau, including the Ruahine Range and eastern hills from Cape Kidnappers southwards, is under an orange warning from 2pm today until 9am tomorrow, with 120 to 160mm expected.
Inland areas of Whanganui and Manawatū north of Marton, including Taihape, face 120 to 170mm from 6pm today until 2pm tomorrow.
A prolonged warning is also in place for eastern hills of Wellington, Wairarapa, the Tararua District and the Tararua Range from 3pm today until 7pm tomorrow.
MetService says 140 to 180mm of rain is expected especially about eastern Wairarapa and the Tararua Range. Intensities of 20 to 25mm per hour are possible in elevated areas, particularly overnight.
A heavy rain watch will also in place in Hawke's Bay outside areas under rainfall warning from 5pm today till 5am tomorrow.
A watch will also be active in Wellington away from eastern hills from 7pm Sunday till 5pm Monday.
East Coast bracing
Gisborne's Mayor is urging people to stay away from beaches as heavy rain, strong winds and large waves hit the region.
Rehette Stoltz said gales could gust up to 130km/h, waves may reach six metres, and dangerous seas pose a serious risk. Many roads are cut off, including SH35 and SH2, and some Hicks Bay residents are self-evacuating.
In Wairoa, flood barriers are being deployed as rivers rise ahead of the heaviest rain.
Councils along the East Coast from Gisborne to Amberley are preparing for further heavy rain and gale-force winds.
Kaikoura and Canterbury
In the South Island, an orange warning is in place for Kaikoura District and Canterbury north of Amberley from 8pm today until 9pm tomorrow, with 110 to 150 mm of rain expected. Peak rates of 10 to 20mm per hour are possible in elevated areas.
MetService warned that streams and rivers may rise rapidly, with surface flooding, slips and hazardous driving conditions were likely.
A heavy rain watch is in place for Banks Peninsula from midnight today until 6pm on Tuesday.
Damaging winds
Severe gales are also expected.
Wairarapa and the Tararua District are under an orange strong wind warning for the 12 hours from 6pm today, with southwesterly gusts reaching 130km/h in exposed places.
In Wellington and eastern Marlborough, north of Clarence, severe south to southwesterlies are forecast from 6pm today until 3pm on Monday, with damaging gusts of up to 130km/h in exposed areas.
Although winds are expected to ease during tomorrow afternoon, they may remain close to severe gale strength in some places until midnight.
Meanwhile, Gisborne/Tairāwhiti south of Poverty Bay, Hawke's Bay and Taihape face severe west to southwesterlies from 5pm today until 7am tomorrow, with coastal gusts also reaching 130km/h. There is a moderate chance this warning could be upgraded to red.
Gisborne and north of Poverty Bay are also under orange strong wind warning from midnight today till 7am tomorrow with severe gale northwesterlies gusting 120 km/h in exposed places.
A strong wind watch will be active in Taupo from 9pm today until 8am tomorrow and in Manawatu in the 12hours from 7pm today.
Strong wind watches will also be active in Whanganui, and Taihape west of State Highway 1, Horowhenua and Kapiti Coast, Marlborough away from the east coast and the Chatham Islands from Sunday evening and night until Monday.
MetService said damaging winds could bring down trees and powerlines, and make travel hazardous, particularly for high-sided vehicles and motorcycles.
Emergency relief fund activated for Ōtorohanga
Ōtorohanga District Council has activated an emergency relief fund for people affected by Friday's storm.
Mayor Rodney Dow said the Mayoral Disaster Relief Fund would help families, small businesses, community groups and marae facing hardship.
He said the focus was on helping people immediately, while other government and insurance support options were explored.
Dow said many evacuated residents had returned home, but some remained displaced.
"I'm just really feeling for the people - we've got one of the primary schools that was flooded.
"It was only a couple of weeks ago I went down because they'd cleaned up their swimming pool so they could do swimming lessons, and it was really happy kids going back to school, going to a great year ahead, and now that's all just going to be paused for a bit."
Dow was meeting with Emergency Management Minister Mark Mitchell and other government representatives today discuss next steps in the recovery.
Mitchell said the country is in a "perpetual cycle of response and recovery", with 25 local states of emergency declared in the past two years.
In Waipā, the district council said its Te Tahi Water Treatment Plant has been significantly damaged. Water has been redirected to Pirongia at reduced flow, and residents are being asked to conserve water for drinking and hygiene only, and to flush toilets sparingly.
