Source: Radio New Zealand
The council publishes multiple different flood maps, which provide broad information about flood risks across the city. Auckland Council
An Auckland homeowner disputes her property is flood-prone, despite it being designated as such on Auckland Council’s online maps.
The council publishes multiple different flood maps, which provide broad information about flood risks across the city.
Stephanie Burgess said the council’s flood modelling used a “broad brush model”, but it had a real impact on value of her Glendowie property and other properties in those areas.
Auckland Council’s flood mapping was based off aerial Light Detection and Ranging (LiDAR) from 2016, which did not accurately reflect the real risk on her land, she said.
“There’s never been any flooding at my property. It requires a pipe to block and a 100-year flood to both happen together.”
The flood-prone marking from the Auckland council maps she had seen was not yet on her Land Information Memorandum (LIM) report, but she was concerned it would be, she added.
Auckland Council’s natural hazard map designates half of Stephanie Burgess’s Glendowie property as flood-prone. Auckland Council
Looking to sell her house, she was worried by the impact this flood-prone designation would have.
“I’m fearful that our property will be devalued because a lot of buyers will not be interested, because they see this notation.”
She was also concerned that people did not understand the difference between a flood-prone area and a flood plane, and the different risk levels between them.
Working in real estate, she said some people would not even enter the open home if there was flood notation on the LIM.
She was calling for the council to factor in site-specific information to more accurately represent the flood risk at properties in designated flood-prone areas.
“I’d like a letter that I can give to buyers that explains the real risk.”
‘Literally within centimetres’
Auckland Council head of planning networks Nick Vigar said the councils across the country were working to provide better information about flood risks, but contested the claim that LiDAR was not an accurate measurement.
“Modern LiDAR is getting within centimetres on your property. Yes, it makes some assumptions where there’s trees and where there’s buildings, but it’s literally within centimetres.”
It was, to an extent, “broad brush”, he conceded, but it was the best information the council had.
“If you want to go and develop your house you should absolutely get someone to come in and survey it accurately,” he said.
The council assessment was only based on the land, so flood mitigation work would generally not be acknowledged in its data, Vigar said.
“If there’s some mitigation in which the landform is changed then, next time we run the LiDAR, that will get brought into the model. But I think the important thing here is: its triggering an assessment of the house on the property.”
The flood-prone designation would need to appear on the LIM report, he said.
“If you get a LIM on that property then you have to understand if there’s one of these triggers across you property … because you need to understand that if you’re developing, the presence of one of those will trigger a flood risk assessment.”
He acknowledged that using decade-old LiDAR was not necessarily fair, but said new data had been gathered in 2024 and would soon be available.
That data was already being applied to landowners who had contested their designation, he said.
“Where we have more accurate information in the new LiDAR, we have inserted it for customers already.”
But getting a property survey would not remove the flood-prone overlay from Burgess’s property, Vigar said.
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand