When replacement is the honest answer
We would rather do the smaller job, and often the smaller job is the right one. A silted chamber can be cleaned out. A broken lid can be swapped. A single failed length of pipe can be repaired without touching the well.
Replacement is the honest answer in three situations.
The chamber has failed structurally
Walls collapsed, concrete broken up, roots through it. Once the chamber has lost its shape there is nothing to repair — the hole is no longer holding its form.
The well is too small for what drains into it
This one is not a fault at all, and it is the most common reason for replacement in Como. No repair adds capacity. If the arithmetic says the roof needs more volume than is down there, cleaning the existing well out simply gets you back to being undersized. More on collapsed soakwells
Repairing it would cost a serious fraction of replacing it
Old concrete that is cracked in several places, with a lid that also needs doing, on a well that is marginal for size anyway. At that point putting good money into it is money spent twice.
You get that assessment on site, in writing, before anything happens. If the answer is that a clean-out will do, we will tell you that instead.
Sizing it to the roof it actually drains
This is the part that matters most, and it is where a replacement differs from a like-for-like swap.
The City of South Perth's benchmark for minor additions with no existing private drainage connection is at least 0.02 cubic metres of soakwell for every square metre of impervious area drained. A 100 square metre roof area needs two cubic metres or more underneath it.
That figure gives you something real to hold an existing system against — and a great many older Como systems do not come close.
The reason is the suburb's history. Como was subdivided in 1905 and built out mainly through the 1950s and 1960s, and only about a third of its occupied dwellings are now separate houses. More than half are semi-detached homes, townhouses or villas. Every one of those subdivisions, rear dwellings, patios and extensions added roof and paving. The wells underneath very often did not grow at all.
So when we replace a soakwell here, the first question is not what was there. It is how much roof and hardstand drains to that point now, and what volume that requires. Putting the same size chamber back into a block that has doubled its roof area since 1965 guarantees the same call next winter.
What drives the price
Five things, in roughly this order.
How much volume is needed
More roof means more cubic metres, which can mean a larger chamber or several of them.
How deep it has to go
Depth depends on the ground at that spot and how high the water table sits. Closer to the Swan or Canning foreshores it sits higher, which changes what is achievable.
Access
This is the one that surprises people. A rear yard reachable only through a narrow side passage rules out machine access, and hand-digging plus barrowing spoil out is a different job entirely. On subdivided Como blocks, access is frequently the biggest single factor.
What is over the top
Paving, concrete, a driveway or established landscaping above the old well all have to come up and go back.
The pipe runs
Whether the existing runs can be reused, or whether they need repairing or re-routing to reach the new position. Stormwater drain repairs
We do not quote drainage sight unseen, because those five are not knowable from a phone call. A licensed plumber comes out at no charge, looks at all of it, and leaves you with a written price. Transparent pricing, no hidden costs — the quote is the price.
How long it takes
A straightforward replacement is usually done inside a day. Old chamber out, new one in at the right depth, pipe runs connected, surface reinstated.
It runs longer when:
- access is tight enough to rule out a machine
- there is concrete or paving over the old well that has to come up
- the roof area needs more capacity than the original, so more than one well goes in
- pipe runs have to be re-routed to reach a new position
- the ground is wetter than expected and the excavation needs managing
Whichever of those applies to you is worked out at the quote stage and written on the quote — not discovered halfway through the day and added to the bill afterwards.
Concrete or plastic for the new one
Depends on the block rather than habit.
Concrete where the well goes under a driveway, a parking bay or anywhere a vehicle sits, because it takes load. It needs machine access to place, being heavy.
Plastic where access is tight, where the site suits a shape concrete does not come in, or where weight is the constraint. Light, quick and will not corrode — but it needs protection above it if anything is going to be driven over it.
We will tell you which suits your situation and why, rather than defaulting to whichever is easier to carry. More on how soakwells work
Book a replacement quote
Tell us where the water ends up and whether anything has been built, paved or subdivided on the block since the original drainage went in — that last one is often the whole story.
A licensed plumber comes out at no charge and leaves you with a written price. Monday to Friday, 7:00am to 4:00pm.