When a Canberra drain backs up
Stop adding water
Hold off flushing, showering and running the dishwasher, so less waste has nowhere to go.
Look at the overflow relief gully
If the grate outside is spilling, the blockage is further down the line. Icon Water says that's what the gully is for: it releases sewage outside so it doesn't come up in your home.
Open the sewer riser
Icon Water's test is simple. A riser filling with water points to its network, so call Icon Water. A dry riser points to your pipes, so call a drain specialist.
Leave Icon Water's side alone
If the plumber finds the blockage is in Icon Water's network, they should report it, not clear it. Icon Water won't reimburse a blockage on its side that a plumber removed.
Drain facts particular to Canberra
Roots lead the list
Icon Water calls tree and shrub roots a major cause of pipe blockages. Hot fat, objects in the pipe, and pipes broken by excavation or heavy vehicles make up the rest of its list.
The gully has a height rule
Icon Water says an ORG must sit 150mm below the lowest internal fixture outlet or floor waste and be kept clear. Paving, decks and landscaping often bury them, and an insurer may not honour a claim on non-compliant drainage.
Your drain is on a plan
Approved sanitary drainage plans belong to the ACT Government and can be found through Access Canberra's plumbing tie search. They show where your line runs before anyone starts guessing.
Stormwater is a separate system
A stormwater blockage above the tie point is yours, and one below it is the ACT Government's. Downpipes and stormwater drains must never be connected to the sewer.
When the blockage isn't yours
If a licensed plumber finds the problem in Icon Water's network, Icon Water reimburses their cost under its Rates for Reimbursement 2026-27. The claim needs the plumber's detailed invoice and invoice number, the property address and an Icon Water job reference number showing Icon Water attended. That reference only exists if Icon Water was called out, which is why the plumber should report rather than clear.
There's no reimbursement when unapproved household waste caused the blockage. For stormwater, the plumber exposes the tie point and contacts Access Canberra, which inspects it. If the blockage is the Government's, you're reimbursed for exposing the tie.
Roots, big trees and digging
Clearing roots is a stopgap if they keep coming back. The lasting fix may mean a new section of pipe or a liner, and digging near a large tree has rules in the ACT.
A private tree is protected if it's 8 metres or taller, has a canopy 8 metres wide, or has a trunk 1 metre around at 1.4 metres above the ground. Groundwork in a protected tree's protection zone needs approval first, and every tree on a nature strip is protected. Our tree roots page and Canberra relining page go further.
Questions to ask the drain plumber
- Did you check the sewer riser before clearing anything?
- How do you know the blockage is on my side of the boundary?
- If it's in Icon Water's network, will you report it and get a job reference number?
- Is my overflow relief gully at the right height and clear of paving?
What we would do
Find the riser and the overflow relief gully now, while nothing is overflowing, and clear anything sitting on them. When a drain does block, check the riser before booking, and tell the plumber what you saw. If roots are the cause, ask for a camera inspection before paying for repeated clearing, and check whether a protected tree is involved before any digging is planned.