Reviewed and updated July 2026
Two Separate Systems, Two Different Jobs
Almost every Melbourne home has two completely separate underground drainage networks, and mixing them up is the single most common reason people call the wrong person or clear the wrong pipe. Your sewer takes dirty wastewater — everything from your toilets, showers, basins, bath, kitchen and laundry — and carries it to the water authority's main for treatment. Your stormwater takes clean rainwater off your roof, downpipes, pits and paved areas and drains it away to a legal discharge point, usually a street kerb, a council drain or a creek.
They never connect (it's illegal to plumb one into the other), they run in different pipes, and they block for different reasons. So the fastest way to work out which one is in trouble is to ask a simple question: is the trouble coming from inside the house, or from the rain outside? That one distinction sorts the vast majority of cases before anyone lifts a grate.
Signs It's Your Sewer
A blocked sewer shows up at your fixtures — the things you use every day inside. The tell-tale signs are:
🔊 Gurgling across fixtures
Flush the toilet and the shower drain gurgles, or empty the sink and the toilet bubbles. When more than one fixture reacts, the blockage is in the shared main line, not a single trap.
👃 Sewage smell
A rotten-egg or raw-sewage smell inside the house or drifting up from a gully outside means wastewater is sitting where it shouldn't and gases are escaping back up the line.
🐌 Everything draining slow
One slow sink is a local clog. Every drain in the house running slow at the same time points to the main sewer line downstream of all of them.
🚽 Toilet levels moving
The bowl rising when you run a tap, or dropping low after a flush, is air being pushed and pulled past a partial blockage in the sewer.
⚠️ Overflow relief gully spilling
That short capped or grated pipe outside, lower than your gutters, is designed to spill sewage outside before it comes up inside. If it's overflowing, the sewer is blocked — act fast.
🌳 It keeps coming back
In Melbourne's leafy east, recurring sewer blockages are almost always tree roots feeding on the pipe — a temporary snake won't hold.
The number-one cause of blocked sewers in the Ranges and Yarra Valley is tree roots working into old terracotta joints, followed by grease, wet wipes and foreign objects. If you're getting the signs above, it's a job for a blocked sewer plumber — and because sewage is a health risk, it's the more urgent of the two.
Sewage backing up inside? Don't wait it out.
Stop using water and call Jack — same-day response across Melbourne's east and the Ranges, camera on every main-line job.
📞 Call Jack — 0425 226 636Signs It's Your Stormwater
A blocked stormwater drain shows up when it rains — and often only when it rains, which is why it catches people out. Watch for:
🌧️ Downpipes overflowing
Water backing up and spilling out the top of a downpipe, or gutters overflowing in a downpour, means the stormwater line below can't take it away fast enough.
🕳️ Pits and grates backing up
A stormwater pit that fills and holds water long after the rain, or a grate that bubbles up instead of draining down, is a clear sign the pipe past it is choked.
💧 Yard or garage pooling
Water sitting in the yard, flooding into the garage, or running across the driveway during rain points to a stormwater line that's blocked or collapsed downstream.
🏠 Moisture near foundations
Damp getting into the base of walls or pooling against the slab after every storm is stormwater with nowhere to go — a slow risk to the building, not just a nuisance.
Stormwater blocks up from leaves and garden debris jamming pits, silt and soil building up over years, tree roots in the joints, and cracked or collapsed old terracotta. The good news: no sewage, so it's less hazardous. The catch: left alone it can undermine foundations and flood a garage, so it's still worth clearing properly. That's what our stormwater drain service is for, and a stormwater health check before storm season catches it early.
Sewer vs Stormwater — the Side-by-Side
Here's the whole thing on one page. If you're still not sure which you've got, match your symptoms across this table:
| 🕳️ Blocked Sewer | 🌧️ Blocked Stormwater | |
|---|---|---|
| What it carries | Wastewater from toilets, sinks, showers, laundry | Rainwater from roof, downpipes, yard, paving |
| Tell-tale sign | Inside fixtures gurgle, drain slow or overflow | Gutters, pits and yard overflow during rain |
| Smell | Sewage / rotten-egg odour | Usually none — just water |
| Common causes | Tree roots, grease, wipes, foreign objects | Leaves, silt, roots, collapsed terracotta |
| Who's responsible | You to the boundary; Yarra Valley Water beyond | You to the discharge point; council / Melbourne Water beyond |
| Urgency | High — health hazard if it backs up inside | Moderate — flooding and foundation risk |
If you're getting signs from both columns at once, you may have two problems — or one collapsed section affecting both — and guessing gets expensive. That's exactly the situation a camera is made for.
Not sure which line it is?
Describe the symptoms and Jack will usually tell you sewer or stormwater on the phone in two minutes — free, no obligation.
📞 Call Jack — 0425 226 636Who's Responsible — and Who to Call
This is where a lot of Melburnians get stuck, because responsibility splits differently for each system. The simple version: anything on your property, up to the connection point, is yours — so a plumber is your first call for both a blocked sewer and a blocked stormwater drain.
Beyond your boundary they part ways. The sewer main in the street belongs to your water authority — across Melbourne's east that's Yarra Valley Water — and if the blockage is on their side, they'll clear it free and can even reimburse a plumber's call-out you paid to investigate. Public stormwater drains under roads, footpaths and parks belong to your local council, while the big regional drains, creeks and flood channels are Melbourne Water's. If water's pooling on your block or your downpipes are backing up, that's almost always on your side of the line. Our full guide on who's responsible for a blocked drain walks through the boundary in detail.
How We Confirm It — CCTV on Every Job
Symptoms narrow it down, but the pipe gives the final answer. On any main-line job I run a CCTV drain camera down the line so you can see on screen exactly which system is blocked, where the blockage sits, and what's causing it — roots, grease, silt or a collapsed section. That means no clearing the wrong pipe and no guessing before you spend money.
Once we've confirmed it, the fix follows the cause. A root-choked sewer or a silted stormwater line usually gets high-pressure hydro jetting — a 5000 PSI jet that scours the full pipe wall clean, not just a hole through the middle like a basic snake. If the camera shows a cracked or collapsed pipe underneath, pipe relining repairs it from the inside without digging up your yard. And if it's an after-hours sewage emergency, our emergency plumber service runs 24/7.
Catching it early always costs less — our guide on the early signs of a blocked drain and what a gurgling drain is telling you both help you act at the gurgle stage rather than the overflow stage.
Frequently Asked Questions
Blocked Drain in Your Suburb?
Same-day service with a camera on every main-line job across Melbourne's east and the Ranges — sewer or stormwater: