Updated 3.28pm: Whanganui wasn't prepared for what has become one of the biggest flooding events in recorded history.
A state of emergency remains as some residents face a third night away from their homes.
PHOTOS:Â Intense flooding hits Whanganui
More than 600 are still without power, and hundreds of roads are impassable due to large slips and washouts.
Building inspectors and health staff are assessing homes in eastern areas this afternoon, where most of the evacuations took place after torrential rain on the weekend.
Whanganui floods - What you need to know
Properties will be given either red, yellow or white stickers - depending on the severity of the damage.
Mayor Annette Main said it's become one in 85 year flooding event and it wasn't forecast.
"This was not forecast. We were not expecting to have such a high amount of water in the river. Otherwise we would have made plans earlier."
Annette Main said the road to her own home is gone.
"It's severely damaged, so that's not a quick fix. It's a pretty large job and I'm not sure how long that will take, but I'm not expecting to be home in the next month."
Insurance Bill
The insurance bill from flooding across the central lower North Island is expected to be in the millions of dollars.
Around 400 people were evacuated from flood hit homes in and around Whanganui over the weekend. Many not evacuated are in isolated or rural areas. Heavy rain also caused a number of road closures throughout Whanganui, Manawatu and Horowhenua..
Extra police are in areas that have been evacuated to ensure properties are secure and provide further assistance to flood-affected residents.
Central Districts police are urging all people in the lower North Island, especially in Whanganui and Rangitikei to avoid any non-essential travel.
Annette Main said officials are yet to assess the full extent of the damage.
"We haven't even had the opportunity to get out there and assess all of our rural roads," she said. "We still can't look at the damage in the houses because they water hasn't receded enough."
A helicopter was used yesterday to survey badly hit areas, and Whanganui District Civil Defence Spokeswoman Cass Alexander is urging people they haven't been able to reach to contact the council.
"In the next couple of day we're going to be talking to people to see what they need and will assess people's needs via helicopter, which may mean evacuations or supply drops of food and other supplies"
"It'll definitely be in the millions but central government has some very clear systems in place to help contribute in these types of situations."
"In these kinds of situations people can get hardship grants and we'll be working that through with the Ministry of Civil Defence and local Civil Defence teams."
Insurance Council chief executive Tim Grafton admits it will take weeks to work out the cost in insurance, but he has no doubt it will be in the millions.
"We don't know what the costs will be. The roads have been washed out, bridges downed and stuff like that so it's going to be a pretty expensive exercise."
The Insurance Council is urging people to take photos of all the damage in their home.
Grafton is urging people to call their insurance providers as soon as they can.
"We know that some houses may have been contaminated by sewage waters and the like. Take photos, keep evidence for your claims."
He adds if anything in the home needs to be repaired urgently - residents need to keep the bill on them, to hand over to their insurance company.
Meanwhile, Labour's floating the idea of changing our town planning rules, to lessen the impact of severe flooding after areas around Wellington were drenched last month.
Leader Andrew Little says an repeated severe weather around the country has raised big questions.
"We need to re-think the way we locate houses and properties ... we have to now start to plan in the long term so people back away from exposure to waterways."
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