The clean-up operation from the record flooding in the central North Island over the weekend could take up to a month.
More than 400 people were evacuated from flood-hit homes in lower North Island towns across Taranaki, Horowhenua, Manawatu, Rangitikei and Whanganui over the weekend.
Flooding caused road and bridge closures, cut power to homes and forced people across the regions to spend the night in emergency accommodation or with friends and family.
The flooding, described as a one in 85-year event, is the worst ever recorded in Whanganui - worse even than the lower North Island flooding of 2004, which led to more than $140 million in insurance claim payouts.
Recovery from the flooding could take a month, Whanganui District Council told Radio New Zealand this morning.
"The next step is to look at ways that we can support our isolated communities as well as help the communities in the urban area clean up," Cass Alexander, from the council's communications department, said.
"So it's looking like it will be a recovery process over several weeks to a month for those people in rural areas."
Building assessments of affected properties will begin today, and the council said it would focus on the recovery for the region's rural areas. The council was also asking for anyone who was affected by the flooding to contact the council.
A Fire Service spokesman said there were no emergency calls about the flooding overnight.
All of the flooding call-outs were now being dealt with by local stations, he said.
"It's just clean up efforts now really," he said.
The damage from the flood in Whanganui could reach tens of millions of dollars, civil defence controller Kevin Ross said.
He told Newstalk ZB there was still more than 400 Whanganui residents out of their homes today.
It was the city's worst flood in recorded history and the city was now in "clean up mode", he said.
"We've estimated 400 out of their houses, that's the assessment we have to do today.
"It's certainly the biggest flood we've ever had here and I've been here for some time," Mr Ross said.
Whanganui was no longer cut off from the rest of country with State Highway 3 open to the north and south, he said.
The flooding is the largest flood event ever recorded in the district, Whanganui Civil Defence said.
The situation was still being assessed, it said in its early morning update today. The focus today would be on identifying rural residents who have not been able to make contact with Civil Defence yet, and who may need assistance, it said.
The Whanganui River level was dropping in the urban area, so work has started on the clean-up operation.
Building inspectors would this morning begin assessing the worst affected urban properties for damage and possible contamination. Residents were warned to treat all flood waters, and areas that had been flooded, as contaminated.
Power has been restored to the Kai Iwi bores, the three major bores which supply the city, and the Westmere reservoirs were now refilling. However, residents were asked to continue to conserve water use.
Excavated areas remain cordoned off, Civil Defence said.
Police are providing mobile units around the city, while the Salvation Army is assisting at welfare centres and the Red Cross has started checking vulnerable residents.
People who were evacuated from their homes were asked not to return home until the property has been assessed and decontaminated if necessary.
Some areas are still without power, or are experiencing disruption to their power supply as repairs are carried out.
Power remained out at Ahu Ahu, Blueskin, Brunswick, Kai Iwi, Paparangi, Rangitatau East, Te Tuhi Junction and Westmere this morning.
It was expected to be restored to all those areas by 6pm.
The Peat St substation was flooded over the weekend but was back up and running by late last night.
Transpower had also been advised of pole issues in Roberts Ave, Civil Defence said.
There were a large number of slips on rural roads, Civil Defence said, while a number of urban roads were still affected by the flooding.
The Dublin Street Bridge is open to service vehicles only, and is unlikely to open to traffic before noon.
The City Bridge is closed until the approaches on both sides of the bridge can be checked and made safe.
"The bridge itself has been assessed as structurally sound. A decision will then be made on whether the bridge can reopen."
This was also unlikely to happen before noon.
The Aramoho Rail Bridge walkway was closed.Access is available west and south on State Highway 3, but State Highway 4 (Parapara) is still closed.
Wanganui East residents can now access the city via a loop at the back of the eastern suburbs. The route is expected to be extremely congested this morning, and motorists are being warned to take extreme care and be patient.
At this stage there were no fears for lives, Whanganui mayor Annette Main said.
"We haven't had calls from people who need immediate help, but we know that people are not able to get out of their homes in the rural areas," she said, speaking to Radio New Zealand this morning.
"We know rural area people are resourceful and usually have supplies, but as days go by and people are unable to get out of their homes because of flood waters, or mostly because of the condition of the roads, then we know that we're going to be putting some other means of getting them out into place, and also getting supplies into them."
That would most likely be through the use of helicopters she said, as had been used in the past.
"Some people are happy to stay, because they've got farms or businesses in the area that they need to keep operating, they've got stock, others are keener to come to town and stay in town while they can't get backwards and forwards to their homes."
The council would today try to make contact with those in rural areas who are cut off by damage to the roads, she said, "some of which ... will take weeks if not months to repair".
The army had also offered to help, Ms Main said, which she described as "fantastic".
"We have the offer of the army for assistance where needed."
People in rural Whanganui might face a month away from their homes and livelihoods after the devastating flooding over the weekend.
Whanganui mayor Annette Main told Newstalk ZB there were "major issues" for rural areas.
Some of the roads alone would take months to rebuild and it would be a long time before Ms Main could get back into her own rural property, she said.
"This is not going to be a quick fix for us,"
"I have an apartment in town...I'm ok there but there are many people in the rural area who won't be able to get in and out," she said.
The mayor told TV3's Paul Henry programme the extent of the damage could be devastating for some residents who relied on rural land for their income.
The damage was worse than the city had ever seen before, she said.
"People have been through this kind of event before but there will be people whose lives are completely turned upside down staying with friends, wondering what's going to happen.
"Many of those rural people and farming or running rural businesses, tourism businesses...there's a lot of work going on there that you can't just up and leave. "
Civil defence would make contact with rural residents today and ensure they were safe.
Briefings are being held this morning to determine the status of the flooding in Whanganui, Rangitikei and Taranaki.
States of local emergency remained in place overnight for the regions after hundreds of people were evacuated due to severe flooding on the weekend.
Civil Defence warned people in all flood-affected areas to stay away from beaches, rivers and streams because of potential contamination.
Whanganui was cut off from the rest of the country due to thousands of large slips but State Highway 3 to the north and south of the city was now open.
In Rangitikei, dozens of people had to be evacuated from the beach community of Koitiata.
A number of Waitotara homes in Taranaki also had to be evacuated after the Waitotara River burst its banks.
In Manawatu, water contamination was expected due to power loss to sewage pumps.
Meanwhile, there had been reports of people who were evacuated from their homes in the Waitotara area being forced to sleep in their cars on Saturday night because emergency accommodation was full, Radio New Zealand reported.
"They came and got us and evacuated us, told us there was accommodation up in Waverley, but it was all full up, so we slept in our car," one resident said.
South Taranaki Mayor Ross Dunlop said there was some confusion caused by the centre first being open at 4pm, closed at 6pm, and then reopening again when the seriousness of the situation became clear.
"There was enough accommodation for people if they needed it, so I was surprised to hear that some people had stayed the night in their cars," he told RNZ.
Other residents were angry at the way they were evacuated from their homes, with one man claiming his grandmother was handcuffed and thrown to the ground by police.
"Police .... said everyone's getting out, so they grabbed my grandmother and they arrested her," he said.
"They were throwing her around. They just treated all the old people with disrespect."
His 67-year-old grandmother wasn't ready to leave because her house was unlocked, he said."
She was saying she wasn't going to go because she's still got her livestock to look after, and the fact that her house wasn't locked up, we still had things to move. They threw her up against the bus .. then they chucked her on the ground. I watched them do that."
Police confirmed to the broadcaster the woman was handcuffed, but couldn't comment on how she was treated during the process.
A tough weekend for residents
The heartbreak for many residents began after the Whanganui River breached its banks about midnight on Saturday, spilling floodwaters into central Whanganui.
The river then continued to rise to record-breaking levels, with the regional council recording a massive flow of 4740cu m per second at the town bridge at 3am yesterday - higher than the previous record of 4680cu m in 1904. The level peaked at 9.1m, significantly higher than the 7m peak the river usually reaches, even at very high spring tides.
Gene Toyne and husband Chris, who live in a low-lying area near Whanganui Airport, left their property on Saturday afternoon.
Mrs Toyne said they had woken early that morning to find floodwaters lapping around their house, and did all they could to safeguard their property.
"We sat down for a cup of coffee around 1.30pm, because we hadn't stopped all day, and in less than half an hour the water was coming through the floor."
The couple had just enough time to grab some clothes, some wine and their two dogs and waded out through waist-deep water.
Mrs Toyne said she hoped to return to the house soon, but was "dreading" the condition she might find it in.
Whanganui Mayor Annette Main said things were "dire" yesterday morning and floodwaters were higher than anyone had seen before. Two evacuation centres had been opened in Whanganui and about 200 people had been processed there.
Civil Defence Minister Nikki Kaye visited the flood-stricken city yesterday and promised the Government would contribute to the cost of repairing flood damage.
She saw the damage at Anzac Parade and in the central city shopping area, before heading to nearby flooded regions. Ms Kaye was due to return to Wellington this morning, ready to brief the Cabinet.
States of local emergency remained in place last night for Whanganui, Rangitikei and Taranaki.
Civil Defence warned people in all flood-affected areas to stay away from beaches, rivers and streams because of potential contamination due to the heavy rain and flooding.
In Manawatu, water contamination was expected due to power loss to sewage pumps.
In Taranaki, a number of homes in Waitotara had to be evacuated after the Waitotara River burst its banks.
Kim Lewis, who lives on the Whanganui side of the river, said fire crews visited her at 11pm on Saturday with an evacuation order. However, she chose to stay at home to take care of her livestock and her dogs.
In Rangitikei, dozens more people had to be evacuated from the beach community of Koitiata.
Rangitikei Mayor Andy Watson said people were "scared" as the floodwaters rose on Saturday night.
"You have people in houses, it's dark, the water is suddenly rising and they don't know where it's going to stop so they're frightened."
The Club Hotel in Marton was "bursting at the seams" with evacuees and stranded travellers on Saturday night, said owner Sandy Beaman.
"Some people were a bit downhearted because it turns out they didn't have any domestic insurance cover. But that's just one of those life things, isn't it?"
A number of highways remained closed last night, including parts of State Highway 3, which were closed yesterday due to slips and flooding. SH1 had been closed between Bulls and Hunterville but was reopened last night. Transport authorities warned drivers to take care.
Cold arrives for darkest days of year
Icy temperatures and severe frosts will replace the heavy rain that caused flooding chaos over the weekend.
Rain will continue to fall across the lower North Island today, but it won't be as heavy as the rainfall which led to the rapidly rising floodwaters.
"The good news is things are looking much more settled over the next couple of days," MetService meteorologist John Law told Radio New Zealand.
"We've still got showers for today, but nowhere near as much rainfall as we've seen over the last few days."
However, temperatures were likely to fall over the next few days, bringing a cold blast across the country, particularly in the South Island.
Mr Law said an area of low pressure had produced "an awful lot of rain in very small spots" across the lower North Island over the weekend, leading to the widespread flooding.
"It was all blocked by a large area of high pressure to the north, and that cold air we had down south as well."
MetService meteorologist Emma Blades warned temperatures are set to drop.
"Temperatures will drop across the whole country over the next couple of days, with severe frosts forecast for sheltered places.
"Add the wind chill factor from strong winds in the east and it's going to start to feel bitterly cold for some."
Ms Blades said night temperatures in Timaru could drop to around -9C the week. The town's average minimum temperature was 0C for this time of year.
Heavy snow is expected in southern Fiordland, Southland, and southern parts of Otago, including Clutha and Dunedin.
Areas around the Canterbury Plains north of Ashburton were likely to get snow near to sea level, she said.
The strong southerly flow would also bring heavy swells to exposed coasts over the next couple of days before easing.
Large swells could persist around Hawkes Bay and Gisborne until the end of the week.
WeatherWatch was anticipating severe frosts, with analyst Philip Duncan saying cold rather than snow would be the main focus this week.
"Last week ended warm for many - this week will not be the same. Welcome to winter - and to the start of the coldest, darkest eight weeks of the year."
Several parts of central Whanganui city remain cordoned off as no-go zones.
Cordons are in place at:
•Taupo Quay/Heads Rd near Suzuki New Zealand
•Taupo Quay/St Hill St
•Taupo Quay/Victoria Ave
•Taupo Quay/Bates St
•Rutland St/Market Place
•Rutland St/Drews Ave
•Market Place/Rutland St
•Wilson St/ Ridgway St
•Both Trafalgar Square public car parks (accessed from Taupo Quay and Wilson St).
•However, business premises in the bottom block of Victoria Ave are able to open, other than MaxiLab, Thai Villa and Stellar.
Road closures - urban:
•Taupo Quay - between Bates St and St Hill St
•Drews Ave and Market Place - between Rutland St and Taupo Quay
•Peat St by the substation
•Peat Park/London St
•Georgetti Rd (open to residents only)
•Mt View Rd
Road closures - rural:
•State Highway 4 Kaimatira to Raetihi
•Kaukatea Valley Rd
•No 3 Line Wakefield St to Kaimatira Rd
•Whanganui River Rd
•Matarawa Valley Rd
•Ahu Ahu Valley Rd
•Kaukatea Valley Rd
•Papaiti Rd closed (near 547)
•Tokomaru East Rd
•Tokomaru West Rd
•Rangitatau East Rd
•City Bridge to Georgetti Rd
•St John's Hill cycleway
- With additional reporting from NZME. News Service