Can you build on land subject to inundation?

I'm completely new to reading overlays and general building stuff, so please bear with me!

Looking at a block of land in Vic that sits along a creek, and on the planning vic website it shows that the block is in an LSIO area (it covers half of the block and is about 800m2).

Original goal was to subdivide the large block, making 3x townhouses on 350m2 (in the green area below) and building a riverfront house on ~450m2 in the red area below.

Is this a terrible idea? For the area we could likely make a good profit on the townhouses and then be able to build an amazing riverfront house for ourself, but I'm not sure how much of a dealbreaker the LSIO is.

e.g. - do it mean we just need to design a build that uses stilts? Does it mean we should avoid the block completely? Is this a "For the love of god, do not buy it" type of scenario?

 

Why on earth would you want to build on a site subject to inundation?

 

Well as mentioned, I'm completely green to property development, land overlays + the possibilities and restrictions of each.

So to answer your question - The reason I'm still considering the land is because I don't know what is possible! If it's a terrible idea (and from your response I'm guessing it is so?), I want to know.

This is in Melbourne, so not the wettest place in the world, and from my cursory searching it sounds like LSIO mean a 1-in-100-year flooding event. I've looked on the council flood maps and this street is not mentioned as one that has flooded.

If it were possible to build there, on stilts I assume, it'd be an amazing riverfront property. But I'm guessing from your response that it's not possible?

 

"Not the wettest place in the world"...but the land has been assessed as a flood risk at 1 in 100 years ? Was that event 99 years ago or one year ago ? And is the risk actually 2:100 ?
Insurance ?

Melbourne water need to consent before council permit can be applied for. You may need hydraulic engineer reports according to Melb water.....

Requirements and guidelines
To get our consent for a planning permit, when your property is affected by flooding, your development proposal must achieve five core flood protection criteria. Of course other factors such as asset or waterway protection may also form part of our response.

Works or structures:

• must not affect floodwater flow capacity
• must not reduce floodwater storage capacity
• must meet minimum floor level height (above flood level) relevant to development location (freeboard)
• must not occur where the depth and flow of floodwaters would create a hazard
• must not occur in circumstances where the depth and flow of floodwater affecting access to the property is hazardous.

 

I hear ya, and apologies if it's coming across like I'm being naive - I am naive, and am looking for information. This is why i've asked if you can put a house in stilts on the block, or if it's just a total no-go. Trying to assess if there's any value in the land or if it's a giant waste of money.

 

If the plan is to build and sell on this block, would you suspect any potential buyer is also going to come across this issue and either use it as a bargaining tool or a reason not to buy (increasing your holding costs, reducing your profits)

 

Possibly. It's a decent-sized block, so the green-square area on the map is where we'd build with intent to sell and then we'd build a PPOR for ourselves on the floodplain.

Sounds like it's too harebrained of an idea though!

 

Oh Ok, I misunderstood.
Pretty ballsy plan if you ask me but you never know unless you ask!

 

A few questions that you'd need to ask the hydraulogist - How deep will the water be across the site for a 1:100 yr flood? What about 1:50 yr? How will that affect drainage on the block? Can you bund the low side of the block or will that impede overland flow?

Can you get insurance if you do build?

Is the site subject to acid sulphate soils profile?

Is the site subject to coastal/estuarine protection restrictions?

 

Further question - Can I build a boat ramp ? Or use the balcony as one

 

You need to invest a little in order to conduct the proper investigations.
Site levels, depth of "flooding", Melb Water consent, finished floor levels of proposed house (assuming it is not in flood flow - no real building opportunity there)
Generally if you impact on a flood plain you displace flood water to elsewhere, so usually unlikely to obtain consent.
It's fairly messy/complicated with a few options, ifs and buts. Get a little professional advice - it will save you in the long run, either way

 

Kevin Mcloud had one on his show where the owners built a house on the Thames London.
It was engineered on a raft that went up and down on the tides, superb engineering..
A couple of million later. Could have bought an island somewhere!

 

Its nowhere near London or on Thames. Its in Buckinghamshire off a canal that likely floods with rain, not tides. Clever use of flood prone land for sure.

 

I've seen that one! This block is along the Merri Creek in Melbourne so pretty different, but it looks like their asking price of $2mil for the entire block is pretty farfetched then: 15-17 Eunson Avenue, Northcote VIC 3070 | Domain

 

It will depend on council and state planning policies. Best place to start would be the local council for some advice and go from there.

If it was in Perth then the answer would be no - we are not allowed to build on 1 in 100 flood plains - even on stilts.

The other consideration as mentioned above is insurance. It may be impossible (or incredibly expensive) to insure anything built on a flood plain.

BTW 3 townhouses on 350sqm is very very very tight, they would be very small.

 

Yeah it would all depend on how much of the corner block is actually usable; if very little / none of it, we'd consider 2 or 3x 2-story townhouses and try to use as much of the "bad land" that we could as parking or similar. If we _could_ use it, then maybe 2 townhouses and 1 feature house.

Either way, it looks like a pretty dud piece of land and the owners trying to offload it - makes sense as it's been on the market for 6 months. If you haven't seen the property that I'm talking about yet, it's 15-17 Eunson Avenue, Northcote VIC 3070 | Domain

 

Yeah sure. What could go wrong.

 

Good luck with STCA on clearing the trees given its location. If its a gem why didnt they get approval for their design ?

 

My thoughts exactly. We've moved on from considering this block now after this discussion, so cheers for the advice! I'm bemused as to why they are trying to get $2mil for it though; the property history says the entire ~1500m2 block (with house on it) sold for $3.5m (I think) a few years back, and a part of the subdivision was then sold for $2.5m, I guess they're trying to be a mixture of greedy and somewhat scammy?

 

Unless you really knew what you were doing, I would steer clear.

Get our consent for a council planning permit | Melbourne Water