Getting a floodplain removed from unitary plan and GIS viewer

[hopetown]

HI,

Looking at a house built right on top of 1% floodplain.

Auckland Council have put a stormwater drain in, which according to stormwater engineer reports (submitted before house was built) diverts any water through piping to bottom of section.

Do you think it is possible to request Auckland Council now remove floodplain from GIS and LIM.

Has anyone done this - or anything similar?

I'm worried this will affect resale value if I buy.

Thank you.

[Davo36]

Not quite sure I understand.

Are you saying the pipe was put in after it was considered to be a flood plain? And the pipe is big enough so that it won't ever flood over the land?

I doubt council will ever remove that, it's probably not in their interest to do so. Because there's only downside for them if they do. Like if they remove the flood plain and then it does flood over land, they could possibly be held accountable for damage done?

I image the only way you could get this done would be to have the council agree that if you have a 3rd party engineer survey this and write a report stating it's very unlikely to ever flood, that they would accept that and remove the flood plain.

But I'd think this is all pretty hard to do.

[Bobsyouruncle]

It's still a floodplain so no they won't.

[hopetown]

Hi Davo36, Yes, the pipe was put in after the property was considered a flood plain - when the property was being developed for the first time (in 2005/6). The council put the drain in after receiving an engineer's (engaged by the developer) report.

I'm not sure whether the pipe is big enough so that it WON'T ever flood again - although I'd hope there was a future proofing element. Current owner says place has never flooded in the seven years he's owned it - and has put that in writing.

However, with weather patterns here in Auckland predicted to be changing to include heavier downfalls, I'm very wary.

In fact, I'm going to walk away. The house is very nice but it comes down to one question for me: "Is it a good idea to shift 100s of thousands of dollars onto an area you know is designated as somewhere that could potentially flood?"

Thanks for your advice. I was concerned about resale (if I'm having this dilemma, someone else will probably have it when I'm selling) but thinking about it overnight, I'm going to find somewhere without this problem.

[hopetown]

Thanks Bob. Appreciate the answer

[John the builder]

Hi Davo36, Yes, the pipe was put in after the property was considered a flood plain - when the property was being developed for the first time (in 2005/6). The council put the drain in after receiving an engineer's (engaged by the developer) report.

I'm not sure whether the pipe is big enough so that it WON'T ever flood again - although I'd hope there was a future proofing element. Current owner says place has never flooded in the seven years he's owned it - and has put that in writing.

However, with weather patterns here in Auckland predicted to be changing to include heavier downfalls, I'm very wary.

In fact, I'm going to walk away. The house is very nice but it comes down to one question for me: "Is it a good idea to shift 100s of thousands of dollars onto an area you know is designated as somewhere that could potentially flood?"

Thanks for your advice. I was concerned about resale (if I'm having this dilemma, someone else will probably have it when I'm selling) but thinking about it overnight, I'm going to find somewhere without this problem.

Good grief Hope
do you know what they are talking about? This is not a situation where water will be up half way the walls but likely sheet flooding and surface water flow, maybe 50mm deep during unusual events. You wouldn't even be aware of the event. The reason to warn owners is as much to avoid building across that possible flow and causing a dam or directing water where it may cause issues for others.

Unless you are in the valley or gully where does the water go from you?

before you make a knee jerk reaction understand what the issues are

You should kook at the council maps half of the north shore is covered by these designations? You could find a high ridge but then you are in High wind and you could slip over the edge?

[Davo36]

Yes hopetown, JohnTheBuilder is right, it won't ever come into the house or anything, but still, the council won't remove it.

Lots of these areas in Auckland too. Seen many, many houses in floodplains.

Regarding the owner's warranty, this means nothing. Years ago, when my now wife and I were trying to buy our first house to live in, we signed up on one on Dominon Road in Auckland. Then got the LIM which showed the whole golf course on it draining through this property, which was located in a dip in Dominon Road.

The agent said the owner had lived there for 20 years, never flooded, he'd put it in writing etc. Well 2 weeks later, we were driving around the area attending open homes and there was a downpour. Well Dominon Road was blocked to traffic and that section was about a foot under water!

But that's very unusual, and yours would only be a sheet of maybe 50mm like JohnTheBuilder says.

[hopetown]

No. I don't know what I'm talking about. That's why I'm asking here. Thanks for your advice jpohn. Much appreciated

[hopetown]

I'm trying to post an image, but it won't let me. Floodplain is right through the centre of the property. Covers almost the whole section

[John the builder]

and where does the water go below to the next guy?

we naturally think pf flood plains as overflowing rivers inundating land for days and weeks.

you need to contact a local stormwater engineer and get a proper understanding of what they are concerned about.

go onto geo maps and have a good look tick the relevant info legend to see what is what.

https://geomapspublic.aucklandcouncil.govt.nz/viewer/index.html

[hopetown]

Thanks John. I got onto geo maps in the first place. that's where I learnt that the floodplain existed.

[hopetown]

Geomaps was where I first found the floodplain. Looks like all the water travels down the street through this one section. Just wondering if that would put future buyers off. Haven't got enough privileges to post the image,unfortunately

[Meehole]

We live in a flood plain, knew when we bought the property and it will always forever be on the title. We have just built a large garage and had to get resource consent and sign to say that we acknowledge we are building on flood plain. Insurance company also has to be notified. You can't get away from it and your case the drain was put there for a reason.

[hopetown]

We live in a flood plain, knew when we bought the property and it will always forever be on the title. We have just built a large garage and had to get resource consent and sign to say that we acknowledge we are building on flood plain. Insurance company also has to be notified. You can't get away from it and your case the drain was put there for a reason.

Thanks Meehole. I've decided to pass this time. The potential for resale worries me. The house is extremely tidy and proced well, but still on market after two months and a lot of people through it. It just seems too good to be true.

[John the builder]

did you get advice from a stormwater engineer?