The Dirt on Hamilton Hill

I’ve had my block on Hamilton Hill for just over a year now and in that time I’ve met a couple of my neighbours. I’ve had coffee with my immediate neighbour on the undeveloped block next door. His name is Warren. He’s a nice bloke. We’ll be sharing a lot over the next year as we build our respective houses.

I’ve also met the fellow who part owns the block beside Warren. Another nice bloke, Peter is his name. I used to work with him, in fact he was my business partner for nearly ten years, but I didn’t know he was my neighbour until I reconnected at a party one night and described to him where I was building. It’s a small world when you start digging around Hamilton.

I’ve also met my neighbours across the ravine. They’re nice folks too who are renovating a huge old Queenslander. Theirs should be done by the time I start my build, but our houses will be facing each other so I’ll be getting to know them quite well in time.

Hello, neighbours across the ravine!

Hello, neighbours across the ravine!

I haven’t met the people behind me though, on the ridge above the site, though I do know some dirt of theirs. I know it well. It’s all over my site. It’s the alluvial soil that was pushed over the ridge into the ravine by the machinery that leveled their original build sites. Probably in the early to mid part of the last century.

When they leveled their blocks, their fill, which was mainly soil and small rocks poured down the slope where it came to rest on my block, settling over the top of the shale rock that makes up the foundation of the hill. Further leveling of my own block for the original house that once stood there and that has since been demolished created a layer of loose soil that also settled on the slope over the foundation rock on my block.

Let's just get rid of some of this fill then, shall we?

Let’s just get rid of some of this fill then, shall we?

Today all that loose neighbourly soil is giving me heartburn. It’s presenting me with a bit of a site problem. When the original soil test was run on the site just after I purchased it, the site was given a “P” for “Problem Site” rating. That was bad enough. Since then, I have engaged the services of an engineer who has a lot of experience with problem sites. His name is Rod Bligh. He’s done a lot of work with the famous Australian architect Gabriel Poole who has designed a lot of houses on problem sites on the Sunshine Coast. Rod has confirmed that mine is indeed a problem that we’re dealing with. He knows one when he sees one apparently and this one makes him nervous.

The layout and contours of the site from above.

The layout and contours of the site from above.

The issue is really all to do with the retaining wall and the garage that I am hoping to build below the house where the block slopes down to the street. As far as I understand the mechanics of soil erosion, it seems that if we were to dig into the side of the hill to make way for a car space, we would run the risk of undermining the slope. Digging further to establish stable footings for the house, which cantilevers out over the slope would further unsettle the hill. Now I’m no geologist but I find the words “unsettle” and “hill”, well, a bit unsettling.

So on the recommendation of the engineer Rod Bligh, I have agreed to a new and more investigative geological survey to be done on the site. That will happen this week.

Strange markings have already appeared on the site to indicate the location of the exploratory metal spikes that will be driven into the fill through to the underlying rock to identify the true nature of the slope we’re building on.

What does this mean?

What does this mean?

And this?

And this?

And why the pink? (Although my niece would love it.)

And why the pink? (Although my niece would love it.)

I’m told the slope is too difficult for modern machinery to do the job. I’m told brawny blokes with sledgehammers will do that job instead. Just like the old days. I wish they’d been there last century when all of that unstable fill was pushed onto my site. Seeing them standing guard might have made my neighbours up on the ridge think twice about pushing their dirt there in the first place.