Changing with the climate
Property owners in Nelson are already feeling the effect of rising sea levels. Skara Bohny reports.
Until recently, climate change has been a problem for the future: things that will happen in 50 years, or in 100 years, slowly over time.
The problems predicted were academic and hard to visualise, things like the frequency of storms or ocean acidity levels. But the climate has already changed, and has already started hitting people where it hurts – the wallet.
The Lewandowski family found this out the hard way, when they applied for resource consent to develop their property on Weka St in Nelson.
They had already started working on the development when they found out new Nelson City Council regulations required them to raise the section 1.5 metres above street level before they could build on it.
Nicole Lewandowski said they had everything priced and evaluated, but when they applied for resource consent, they were informed that they would have to raise the floor level.
‘‘We didn’t know that we’d need to do that originally, otherwise we never would have gone ahead with the development, just because it cost so much more.’’
She estimated that raising the ground level had added almost half a million dollars to the cost of the development.
The Lewandowskis were victims of unfortunate timing, as they started their development process in 2015, about the same time the new council regulation came in.
In fact, the increased ground level requirement is an update of existing regulations.
Council group manager for environment Clare Barton said developments in some areas of Nelson had long been required to be raised above street level due to flood risk, but the levels changed over time.
‘‘Determining the actual level is a moving feast, because it’s always based on the latest models,’’ she said.
‘‘All the other houses on that street will have raised floors [above street level] based on the current science of the time they were built.’’
The latest requirements were based on Ministry for the Environment (MFE) modelling of climate change.
The risks for Nelson city and Tasman district highlighted by MFE were increased chances of coastal inundation and river flooding, and increased frequency of heavy rainfall events which could overwhelm stormwater infrastructure.
Barton said the council had been informing and consulting affected residents for the past year about the new regulations for developing property.
‘‘There was actually pushback on this, but they’d rather know it and be informed than not,’’ she said.
‘‘This only impacts people who are about to develop.’’
Barton said The Wood was known to be a flood-prone area, and this meant steps had to be taken to address that risk.
‘‘Buildings from the 1910s and 1920s have notes that say they are prone to flooding, so it’s not a new phenomenon.’’
Raising the floor of the building higher than the street level has long been a method of flood risk mitigation; the difference is the height the Lewandowskis had to build up.
‘‘When people saw us building the retaining wall, they thought we were building the fence,’’ Lewandowski said.
The ground had to be built up to 1.5m above street level before building could start, and by the time the foundations were built, the floors would be about 1.7m above street level.
‘‘I could have understood maybe half a metre, but 1.5, that is quite a lot.
‘‘And it looks quite odd, too . . . It makes them stand out too much. But we’d already started the process when we found out, and if we’d pulled out at that point, we would have lost money on it,’’ Lewandowski said.
‘‘I just think what they were asking was just too much . . . and none of us think it’ll really be effective.’’
Lewandowski said a lot of people in the neighbourhood opposed the development when they found out about the height requirements, and it had been a fight to have it go ahead at all.
‘‘If they weren’t raised up, then it wouldn’t affect [the neighbours] so much, but now it’s going to be 1.7m higher. That’s going to affect their investment, you know, afternoon sun and all that.’’
She said that despite the extra costs involved, she was glad that the work had been done.
‘‘People say it’s going to look quite odd, but when you’re there it’s still nice, it’s private. I’m quite glad that we have done it. It makes it more safe-feeling,’’ she said.
‘‘I am glad that if something does happen, then we’re prepared for it. But [the council] need to think about what they’re going to do with all the existing houses. Because imagine if something does happen – what is everyone going to do once it does happen?’’
The raised levels are, in part, a preparation for the so-called one-in100 storm, which is referred to more officially as a 1 per cent Annual Exceedance Probability event in council planning. In other
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