Responsibility for sewer pipes is split between the property owner and the water utility, and misunderstanding the split catches many owners out.
As a general rule in South East Queensland:
- The property owner is responsible for the private sanitary drainage — the pipes that collect waste from the house and carry it across the property to the connection point.
- The utility is responsible for the sewer main and, in many cases, the connection branch from the main.
The exact handover point differs between properties. Some blocks have the sewer main running through an easement in the backyard; others connect at the front boundary. Your property's sewerage service diagram (site plan) shows where the private drains run and where they connect — your conveyancer received one when you bought, and copies can be ordered from the utility.
Practical implications:
- A blockage in your private drain is your responsibility to clear, even if it is caused by roots from a street tree — though compensation claims are sometimes possible.
- If a blockage is found to be in the utility's main, report it to them; clearing that section is their job.
- Overflow relief gullies, inspection openings and boundary shafts on your land are part of your private system and must be kept accessible.
If a drain professional finds the fault sits on the utility side, they should tell you so you can lodge it with the utility rather than paying for work that is not yours to fund.