Andy has decided to lift his house which is on a flood plain in Sandringham by about 800mm. Photo: Supplied
Some Aucklanders are lifting their houses to avoid damage from future floods.
Research commissioned by NIWA says it is a cost-effective solution, but it will not work for everyone.
Sandringham resident Andy's house is on a flood plain near Central Auckland. When it flooded in January he decided something had to change.
"The water came through about six inches deep," he recalled. "It's not like it was up to the windows or anything like that, but it's just enough to ruin all your furniture, ruin all your carpets."
He did not want to move out, so he decided to move up - by about 800 millimetres.
"Since then we haven't been able to get it repaired anyway, so we thought we might as well lift it," he said.
Andy said the floors of his 100-year-old villa were already too low, so it was an easy decision to make. "The floor level was below the minimum current standard of 500mm above the 100-year flood level," he said.
"When we bought it I said: Oh well, you know it's a 100-year flood... that only happens every now and then. Then we had the January event."
With rising sea levels and more frequent storms, NIWA is researching ways to mitigate flood risks.
NIWA says lifting timber houses is more straightforward and cost effective than lifting brick or concrete buildings. Photo: Supplied / Andrew
Coastal climate risk and infrastructure manager Connon Andrews said lifting a house by up to two metres was a great option, but only under certain circumstances.
"Houses located in environments that are either frequently flooded or potentially affected by very extreme events, raising houses in those situations is a very viable alternative," he said.
For timber houses, Andrews said the process was relatively straightforward. But buildings made of brick or concrete were another story.
"Raising a normal timber-framed house is feasible and cost-effective against a new build," he said. "However, when you consider concrete construction that cost starts becoming a bit less financially viable."
Location was another factor. A raised house could only do so much if the rest of the street was under water, Andrews said.
"This piece of research is focused on the house itself, it didn't consider all the ancillary infrastructure around it," he said. "Yes, if you raise a house the house will be protected but everything else around it will be inundated."
Andy said the floors of his 100-year-old villa were already too low to meet modern standards, so after it flooded in January lifting the house was an easy decision to make. Photo: Supplied / Andrew
Andy said the floors of his 100-year-old villa were already too low to meet modern standards, so after it flooded in January lifting the house was an easy decision to make.
Community group West Auckland Is Flooding chairperson Lyall Carter wanted the council to shoulder some of the responsibility.
"A lot of the reason why the flooding happened in the first place was because of the lack of maintenance," he said.
"I think there's a moral obligation on the council, who did very little to maintain the streams. Surely the moral obligation is on the council to pay for the raising of these homes."
Andy agreed. "It would be really good if we could actually get some money from the local government or something like that to contribute to us making our house more liveable and less at-risk," he said.
"Because it's taken a big chunk out of our renovation budget."
He said the council should help people upgrade their homes so future floods would be less destructive.