Before you sell: fix the four jobs, skip the rest.
Drainage does not add a premium in Toowoomba. It protects the price you already have. Clear and camera a known problem line for $570 to $1,350, connect a downpipe that is discharging against a wall for $450 to $1,500, regrade the one low spot for $600 to $2,000, and clean every grate for $250 to $600. Those four stop a building inspector writing the sentence that turns into a $10,000 to $20,000 negotiation. A full back yard ag drain system three weeks before an auction does not.
Every job, what it costs, what it protects, and the verdict
These are 2026 Toowoomba region figures and honest verdicts, including the jobs we would rather you did not give us. The test for every line is simple: will a buyer, an agent or a building inspector notice this, and what does it cost you if they do.
| The job | Typical 2026 cost | What it realistically adds or protects | Verdict |
|---|---|---|---|
| Clear a known blocked line and camera it, with a written report | $570 to $1,350 combined | Removes the most common inspection finding and gives you a document to hand a nervous buyer | DO IT |
| Clean out every grate, gully, pit and channel drain | $250 to $600 | Presentation, and it stops the damp smell and water staining that inspection day always finds | DO IT |
| Connect a downpipe that currently discharges at the base of a wall | $450 to $1,500 for one or two downpipes | Kills the damp patch, the efflorescence and the subfloor moisture reading that get photographed | DO IT |
| Regrade or spoon drain the single low spot that ponds near the house | $60 to $130 per metre, usually $600 to $2,000 | Directly answers the poor site drainage finding, and it looks tidy rather than surgical | DO IT |
| Repair a collapsed or cracked section the camera has proven | $650 to $2,500 | Converts a discount lever into a paid receipt. Buyers argue with unknowns, not invoices | DO IT |
| Full stormwater reconnection of the whole house | $2,500 to $6,000 | Worth it only where there is a live, visible defect. Otherwise you rarely see the money again | ONLY IF flagged |
| Grated channel drain across the driveway or garage threshold | $180 to $320 per metre, usually $1,000 to $3,000 | Pays only where water visibly runs into the garage. A buyer who sees the stain will demand it | ONLY IF water enters |
| Ag drain the whole back yard purely for the sale | $80 to $140 per metre, usually $4,000 to $9,000 | Almost nothing at sale. Buyers do not pay for invisible pipe, and fresh trench lines advertise a problem | SKIP IT |
| Detention or retention tank nobody has asked for | $6,500 to $14,000 | Nothing, unless a development approval requires it. It is a compliance item, not a selling feature | SKIP IT |
| Repaint a damp stained wall without fixing the cause | $300 to $900 | Nothing. Inspectors carry moisture meters and the reading goes in the report regardless of the paint | SKIP IT |
| Landscaping or garden beds over a known drainage defect | $1,000 to $5,000 | Worse than nothing. It looks like concealment and it usually makes the ponding deeper | SKIP IT |
| Camera report and a written scope for a defect you have decided not to fix | $220 to $450 | Lets you control the story and cap the discount at a real, quoted number instead of a buyer guess | DO IT |
Indicative Toowoomba region figures for 2026. Full ranges are on the pricing guide and in the cost guide.
What a building inspector actually notices
A pre-purchase inspection in Queensland is carried out to the Australian Standard for property inspections, and site drainage is one of its own headings. The inspector is not guessing: they walk the perimeter with a moisture meter and a torch, and they get under the house. In Toowoomba the same findings come up over and over.
- Ground that falls back toward the building. On a reactive black soil block the ground moves seasonally, so a fall that was fine at construction can reverse over 20 years. This is the number one written finding.
- Downpipes discharging at the base of a wall. Cheap to fix, brutal in a report, because it is the direct cause of the next three findings.
- Ponding within a metre of the slab or the stumps. Photographed, measured and quoted against.
- Subfloor dampness, mould smell and rusting ant caps or stumps. This is where a $1,200 drainage job becomes a $15,000 conversation about structural repair, whether or not that is fair.
- Efflorescence, the white salt bloom on brickwork. It tells an inspector water has been moving through that wall for years.
- Cracking in a Class E or P reactive site. Toowoomba buyers already know about black soil. Visible moisture next to a crack turns a normal seasonal crack into a suspected footing problem.
The important part is what happens next. A buyer with an unsatisfactory building and pest report has a contractual right to walk or to renegotiate, and the discount they ask for is never the cost of the repair. It is the cost of the repair plus their uncertainty. That gap is the money you are protecting, and it is why the $1,500 jobs matter more than the $9,000 ones.
Fix it or disclose it: how to decide
Run the decision on three questions, in this order.
- Will an inspector find it? If it is visible, smellable or shows on a moisture meter, assume yes. If it is a hairline crack in a pipe 900 millimetres underground that has never surcharged, probably not.
- Is the fix under about $2,500 and can it be finished 6 weeks out? If both are true, fix it. Under that figure the repair is always cheaper than the negotiation.
- If it is bigger or the campaign has started, can you quote it? Get a written fixed price and hand it over. A buyer who has a $4,200 quote in front of them argues about $4,200. A buyer who has a wet corner and no number argues about $15,000.
On the legal side, Queensland now runs a seller disclosure regime, but it is aimed at title, encumbrances, rates and statutory notices rather than the physical condition of your drains, and physical condition is still tested by the buyer through the building and pest condition in the contract. That is not a licence to conceal. Actively hiding a defect, or answering a direct question falsely, is a different matter entirely and carries real risk. Ask your solicitor about your contract. Our view as tradespeople is simpler: a documented, quoted, honestly disclosed defect costs you less than a discovered one, every single time.
Selling in the next few months?
We will walk the block, tell you which of these jobs your house actually needs, and quote only those. If the answer is do nothing, that is what we will say.
Timing: how long before the campaign
The work itself is quick. Most of these jobs are 1 to 4 days on site, and a downpipe reconnection or a grate clean out is often half a day. The constraint is the ground, not the plumbing.
| Stage | When to do it | Why that timing |
|---|---|---|
| Camera inspection and assessment | 8 to 10 weeks before photos | You need to know what you are dealing with before you decide what to spend |
| Any work that opens the lawn | 6 to 8 weeks before photos | Turf knits back in about 4 to 6 weeks over a warm Toowoomba summer and 8 to 12 weeks through a frosty winter |
| Downpipe and surface work in garden beds or gravel | 3 to 4 weeks before photos | No lawn to recover, so mulch and a rake finish it the same day |
| Grate, gully and channel clean out | The week before photos | Presentation item. Do it last so it still looks clean on inspection day |
| Anything requiring a council plumbing application | 10 to 14 weeks before photos | Application, inspection and certificate add time that is outside anyone control. See our council approval guide |
Winter matters here more than in Brisbane. Toowoomba sits high enough to get regular frosts, and frosted turf does not knit. If you are listing in spring, the drainage work needs to happen in late summer or early autumn, not in August. If you have left it late, do the jobs that do not touch lawn and quote the rest.
Two jobs we would tell you not to bother with
We would rather lose the work than sell you something that does not come back.
A full back yard ag drain system just for the sale. It is $4,000 to $9,000 on a typical block, and no buyer has ever paid a premium for pipe they cannot see. Worse, a set of fresh trench lines across the lawn in the listing photos reads as an admission: this yard had a water problem. If the yard is genuinely boggy on inspection day the calculation changes, because then the buyer sees the problem instead of the fix. Otherwise, keep the money, disclose honestly, and let the new owner do it in their own time. We cover the job properly on the ag drains page for when it is actually the right call.
A detention or retention tank nobody has asked for. At $6,500 to $14,000 this is the most expensive thing on the list, and it is a compliance item tied to a development approval, not a feature a buyer values. If your property has an approval condition requiring one, that is a legal obligation and a different conversation. If it does not, installing one before a sale is money set on fire.
Two smaller ones while we are here: do not repaint over a damp stain, because the moisture meter reads through paint and the report will note both the reading and the fresh paint, which looks far worse than the stain did. And do not build a garden bed over a low spot. It holds more water, it puts soil against the cladding, and every inspector in Toowoomba has seen the trick.
What to ask the tradesperson quoting your pre-sale work
- Which of these jobs would you skip if it were your house? An honest drainer will name at least one.
- Will this show in the listing photos, and how long until the lawn recovers? If they have not thought about it, they are not thinking about your sale.
- Can I have a written report as well as an invoice? The report is the thing you hand a buyer. The invoice on its own proves you spent money, not that the problem is gone.
- Is any of this notifiable or permit work with Toowoomba Regional Council? Unapproved plumbing work found at sale is a much bigger problem than the original defect.
- What will this look like in a building and pest report after the work? The right answer is that the finding disappears, not that it looks better.
- What is the honest expected life of the repair? See how long drains last in Toowoomba for the benchmarks.
If you want the wider view on choosing a contractor, our guide on how to choose a drainer in Toowoomba covers licences, insurance and the red flags. If a tenant is still in the property while you prepare it for sale, the access and repair rules on the landlord obligations page apply right up to settlement, and if a storm hits mid campaign, the first hour emergency steps will save you the panic. Once the house is sold, hand the new owner the maintenance schedule.
Find out which pre-sale drainage jobs your house needs
Tell us your listing date and what you have noticed. We reply within 1 business day and quote only the work that protects the price.
Selling and drainage questions
Does drainage work add value when you sell in Toowoomba?
What do building inspectors write down about drainage?
Should I fix a drainage defect or disclose it?
How long before listing should drainage work be done in Toowoomba?
Do I have to tell a Queensland buyer about a drainage problem?
What drainage work should a seller skip?
General information for Toowoomba sellers, current for 2026. It is not legal advice. Your solicitor advises on disclosure and your contract, and your agent advises on price. We only advise on the water.