G'day all,
Does anyone know if there are requirements for the depth of installation of soakwells in Perth?
More specifically, is there any requirement for the top of the soakwell to be a certain depth below ground level?
Or can it be installed any depth, including the top of the soakwell protruding above ground level?
Dunno - but why would you?
Anywhere within 5km of the river or a swamp - and being coastal plain, that is a LOT of Perth - will have problems with the water table being quite high. Even properly installed soakwells back up and overflow in a good winter rain.
So go deep as you can and 1.5x as many as u think u need.
If I was installing one I'd look at having the top cover of dirt at least 300-500mm.
We've built recently and had the pad raised during the process, whilst building the pad was battered but the builder knew we weren't going to leave it like that, ie- we were having a retaining wall installed after hand over.
Now we're having a retaining wall installed and found that the soakwell protrudes above the level of the natural ground level.
The base of our retaining wall is at the level of what was the natural ground level.
I'm thinking that the plumber that installed the soakwell, didn't put it as deep as he should have due to the batter of the pad.
But the site plans clearly show the natural ground level at that spot and the top of the soakwell is higher than that by around 100mm.
And even the plans were drawn showing the batter stopping short of the location of the soakwell, meaning that the soakwell should have it's top lower than the level indicated on the plans.
I'm trying to find out if there is a minimum top cover required for soakwells, if there is, I can hit the builder up to sink the soakwell further, due to the fact that the block level wasn't taken into account by the plumber.
Ahhh gotya
Shonky way to resolve it but you probably thought of that already, wait for the plumbers to reply, ignore me. 
typically, plumbers leave soak wells to the apprentice, with very little directions apart from "remember that water flows down hill"
typically the apprentice has no idea of any site plans, and just digs a hole [as shallow as he can get away with], chucks in the soak well, hooks it up and fills it in.
If you want your soak well to work , dig around it to the width of your shovel, and fill the surrounding space with blue metal - to give the well a chance to drain.
Drop some rubble / broken tiles in the bottom so the well doesn't undermine itself.
Fit a breather / overflow pipe, so in a heavy downpour the lid doesn't get blown out, and cut a 32mm or so hole in the bottom of the downpipe, so if the well fills up - you don't get water backing up through the downpipe and into your eaves and possibly ceiling.
stephen
In west Aussie you are required to be a minimum of 1.5 meters away from your footing of your house to the edge of the soak well.
There is no depth requirement, the deeper you dig the higher the water speed hitting the surrounding ground and the more likely it is to sink, so 100 below paving is cool. Hope this helps
Select to expand quotesn said...
typically the apprentice has no idea of any site plans, and just digs a hole [as shallow as he can get away with], chucks in the soak well, hooks it up and fills it in.
Indeed, I thought it would be something like this, figured the batter of the pad influenced the depth decision, rather than the site plan showing the RLs.
Was just wondering if I had any come back on the builder to get them to fix it, or if I'll have to get in and dig it down further myself.
Yep, but I can't ask till monday, so wanted to do some homework on it over the weekend.
I prefer to discuss things like this from a position of knowledge so I don't get the wool pulled over my eyes.
I was told 500mm by someone at city of wanneroo when I enquired about doing mine. At that depth you can drive over them I think (not that you really do of course but handy if you level the backyard).
I bought mine from this soakwell place near midland (mcm) and allowed roughly 350l per downpipe so maybe call them ask them.
Building regs are pretty specific about this sort of stuff. I'd check with the shire building inspector who will be right onto it.
Select to expand quoteDave Whettingsteel said...
Building regs are pretty specific about this sort of stuff. I'd check with the shire building inspector who will be right onto it.
Yeah I would have thought so, but can't find anything on the council website.
Anyway, put the details to the builder, who has forwarded to the plumber, I've also called them but have not made successful contact yet.
They'll find out I don't give up.
Can I add to the question, how close can you build a cement / brick wall to an existing soakwell
Select to expand quoteDelwyn said...
Can I add to the question, how close can you build a cement / brick wall to an existing soakwell
It would depend upon the weight loading and ,or the lateral load this placed on the footings of the wall, the size of the footings would also be a factor . Is the soakewll plastic sided , brick , concrete , 10 metres deep or 300mm deep?
All to be factored in before building a wall that fails at a later date.
