One of the most common points of confusion for Newcastle homeowners dealing with a drain or sewer problem is the question of who is responsible for fixing it — and therefore who pays for it. The answer depends on where in the drainage system the problem is located, and there's a clear legal and practical dividing line that applies to all properties in the Hunter Water service area.
The Basic Rule: Boundary Trap Is the Dividing Line
Every property connected to the Hunter Water sewer network has a boundary trap — a specific fitting in the drainage system that marks the legal boundary between the private drain (your responsibility) and the public sewer main (Hunter Water's responsibility). The boundary trap is typically located near the front property boundary, often close to the front fence line.
In simple terms:
- Blockage on your side of the boundary trap: Your responsibility. You organise and pay for a plumber.
- Blockage in Hunter Water's sewer main (past the boundary trap): Hunter Water's responsibility. They attend and clear it at no charge to you.
What Is a Boundary Trap?
A boundary trap is a U-shaped fitting installed in the private drain at the property boundary. It serves two purposes: it creates a water seal that prevents sewer gases from the public sewer main from entering your private drain, and it provides a legal demarcation point between private and public infrastructure.
On most Newcastle properties, the boundary trap is accessible via a small inspection cover set into the ground near the front fence. It looks similar to any other inspection shaft — a concrete or plastic cover over a small underground chamber. If you're not sure where yours is, Hunter Water can tell you when you call their fault line.
How to Determine Which Side the Blockage Is On
When a plumber attends a sewer blockage, one of the first things they do is try to determine whether the blockage is in the private drain or the public sewer. There are two quick methods:
Visual Inspection of the Boundary Trap
If the boundary trap inspection chamber is accessible, your plumber can open it and check the water level. If the chamber is full and overflowing, the blockage is in Hunter Water's main (the water has nowhere to go). If the chamber is empty or at normal level, the blockage is in your private drain upstream.
CCTV Camera Inspection
A camera run from inside the property through the private drain to the boundary trap — and if possible beyond — will locate the exact position of the blockage and confirm which side of the boundary it sits on. If the camera can travel freely to the boundary trap, the private drain is clear, and the issue is in Hunter Water's system.
Contacting Hunter Water for a Sewer Issue
If you or your plumber determines that the blockage is in Hunter Water's sewer main, contact Hunter Water's faults line on 1300 657 657 (available 24/7). Hunter Water will attend and clear the blockage in the public main at no charge. They will not, however, repair any damage to your private drain that may have been caused by the public main issue — that remains your responsibility.
Common Scenarios and Who's Responsible
| Scenario | Responsible Party |
|---|---|
| Single drain blocked (sink, shower) | Property owner — private drain issue |
| Multiple drains backed up, boundary trap full | Likely Hunter Water — blockage in public main |
| Tree roots in private sewer lateral | Property owner — private drain |
| Cracked private drain pipe | Property owner |
| Sewage overflow from street infrastructure | Hunter Water |
| Blockage between house and boundary trap | Property owner |
What Happens When It's Unclear
Sometimes a blockage sits right at or near the boundary trap, making it ambiguous. In these cases, your plumber may need to use CCTV to confirm the exact location before recommending the next step. If Hunter Water attends and determines the blockage is actually in your private drain rather than their main, they'll advise you to organise a private plumber — they won't clear a private drain blockage.
💡 Not sure which side your blockage is on? Call us — we'll inspect the drain, locate the blockage, and advise clearly on whether it's a Hunter Water issue or one we can fix for you. Call 0491 570 006.
Does Hunter Water fix tree root blockages?
If tree roots are in Hunter Water's sewer main, yes — they'll clear them at no charge. If tree roots are in your private drain (which is far more common), that's your responsibility. The vast majority of tree root drain problems in Newcastle are in private drains, since the private sewer lateral (the pipe from your house to the boundary trap) is typically the oldest pipe on the property and most susceptible to root intrusion.
Can I claim the cost of a private sewer repair from Hunter Water?
Generally no — private drain repairs are the property owner's responsibility regardless of the cause. However, if a Hunter Water main fault caused damage to your private drain (e.g. a surcharge in the public main pushed sewage back and damaged your private pipework), you may have grounds for a claim. Document the damage thoroughly with photos and CCTV footage and contact Hunter Water's customer service to discuss.
📞 Need a plumber in Newcastle? Call 0491 570 006 for same-day service across Newcastle and the Hunter region.