At Hastings Sports Centre evacuation centre, residents told RNZ of dramatic rooftop rescues, and having lost everything.
Fola Samoa supervises a group of 12 men who work at a Johnny Appleseed orchard in Pakowhai.
He said they were eating breakfast when they realised how bad the flooding had become.
"One of the men, came to me and said 'boss, there's a river come through to our house'," Fola said.
"I walked through to the front door and I was shocked, because our driveway was like a, like a river."
Samoa said it was "like a tsunami" - and reminded them of the devastating tsunami that wreaked havoc in Samoa in 2009.
They tried to pack some essentials into a van about 11am, but it was too late - instead they threw their belongings on to the roof of their home.
The group was on the roof for four hours watching the water rise, before flagging down a helicopter which rescued them.
"All our bags are still on the roof.
"One of our orchards, Granny Smiths, all gone."
He said his bosses would visit them at the centre on Wednesday.
"We've got more food, more water, more clothes, we are all fine here."
"We are all good."
'Just numb' - Pakowhai resident
Pakowhai resident Ross Cocking said he had lost everything.
"Lost my house, business, cars, customers' cars, everything was flooded."
His partner Raewyn Nelson, who was with Cocking at the evacuation centre, got out of the house about 11am and was driving in "a foot and a half of water" while Cocking prepared to leave.
"Everything was floating, the couches, the bed, TV was had it," Cocking said.
"Got a whole lot of clothes and food ready, by the time I had turned around which was about five minutes, it had gone up another foot and a half inside the house."
Cocking said he managed to leave his home and get to his shed which had a mezzanine floor, thinking he would be able to wait out the flooding.
"I was keeping an eye on the water down below, it was coming up quite fast, and I'm going 'oh, this is not good'.
"I could hear choppers up above, and I thought, if I don't go now, I'm not going to get out of here."
He swam under water and felt his way to the door, surfacing outside the house and making his way to a tree.
"The torrent going through there was like swimming in a river, full speed.
"Managed to ninja across to the house, managed to climb up on the roof, and then wave at choppers and the IRB [rescue boat], and an hour and a half later he came and picked me up."
He saw cows, sheep and horses drowning.
Cocking said it was hard to comprehend what had happened.
He had had no contact with friends or family.
"Just numb really, I'm not looking forward to going back in a couple of days.
"That's when it'll really hit home what happened."
Cocking was tearful when he described his experience at the Hastings Sports Centre, where many other Pakowhai residents also sought refuge.
"Just everyone's sorta helping each other out, it's pretty cool really.
"Hopefully in three or four weeks, we'll have a catch up and have a beer somewhere, and we'll all get together and tell our stories."
National Emergency Management Agency advice:
- Put safety first. Don't take any chances. Act quickly if you see rising water. Floods and flash floods can happen quickly. If you see rising water do not wait for official warnings. Head for higher ground and stay away from floodwater.
- Do not try to walk, play, swim, or drive in floodwater: even water just 15 centimetres deep can sweep you off your feet, and half a metre of water will carry away most vehicles.
- Throw away food and drinking water that has come into contact with floodwater as it is often contaminated and can make you sick.
- If you see a downed power line or damaged power equipment please stop, retreat and stay well clear.
- Stay at home if it is safe to do so and have an evacuation plan in case your home becomes unsafe to stay in.
- If you have evacuated, please stay where you are until you are given the all-clear to go home.
- People should stay up to date with the forecasts from MetService and continue to follow the advice of civil defence and emergency services.
- A National State of Emergency is in place for an initial period of seven days and applies to regions that have declared a local State of Emergency.