What Hobart's drains have going on
Roof water in the sewer
The City of Hobart says many properties send roof stormwater into sewer pipes, and that this can cause sewer overflows during heavy rainfall.
The 72 hour test
Council says that if there's been no rain in the past 72 hours, a drainage problem is unlikely to be stormwater. Look at the sewer or a leak instead.
Fat sets in the cold
TasWater says most fats and oils turn solid in cooler temperatures and congeal in the pipes, catching hair, wipes and floss into blockages.
Roots get in
TasWater names tree root infiltration, along with a build-up of fats and solids, as a cause of sewer blockages.
Where TasWater's pipe stops
TasWater maintains its pipes from the main to the connection point on your property. The sewer pipe from the connection point to the house, usually starting at the inspection opening, is the private service line and is yours.
That makes the inspection opening the place to start. If a plumber finds the blockage on the main side of it, they should contact TasWater and wait. TasWater says plumbers may not work on its infrastructure without permission, and it won't accept charges for repairs it didn't authorise.
When TasWater decides the blockage is in its system and authorises a plumber to clear it, it will consider reimbursing that work. You'll need its reimbursement form and the plumber's invoice. Our sewer ownership guide sets this beside other states' rules.
The overflow gully is your safety valve
The overflow relief gully (ORG) is the grated fitting outside that lets sewage escape outdoors if the drain blocks, instead of coming up inside. TasWater says owners are responsible for having a properly designed, working ORG, and must never cover it with pavers, pot plants, mulch or garden beds.
If you don't have one, or yours is an old fitting, TasWater suggests contacting a licensed plumber. The costs fall to the property owner.
Stormwater blockages and the City of Hobart
Stormwater is the City of Hobart's business, except where a combined sewer and stormwater system exists, which TasWater looks after. The City owns over 350 km of stormwater pipes.
On your side, overflows from grated fittings around the house or blockages in your pipes are a job for your own plumber. So is the opening under your driveway where it meets the road: Council says keeping it clear of leaves and debris is the owner's responsibility.
Sewage overflowing? In this order
Stop the water
No showers, flushing or washing until it's cleared.
Call a drain plumber
As TasWater asks, the plumber goes first and works out where the blockage is.
If it's TasWater's, stop
The plumber contacts TasWater and waits for permission. Keep their notes.
Flooding in the house?
TasWater asks you to contact it as soon as you know of flooding from the water or sewerage system, day or night.
Questions to ask a Hobart drain plumber
- Is the blockage before or after my inspection opening?
- If it's TasWater's, will you call them before going further?
- Are my downpipes connected to the sewer, and should they be?
- Can you camera the line to check for roots or cracks?
What we would do
Uncover the inspection opening and the overflow gully before the plumber arrives; it saves time and tells everyone quickly whose pipe is blocked. Ask the plumber to stop and ring TasWater the moment the blockage looks like it's on the main side, because unauthorised work on TasWater's pipe won't be paid back. And if the drain only misbehaves in heavy rain, ask whether roof water is going into your sewer.