Sewer Blockages

In the event your property experiences a blocked sewer contact Shoalhaven Water immediately. This is generally first noticed by drains or toilets not clearing quickly or by an overflow in the yard gully.

Tree roots

Signs of a sewer blockage

  • Toilets, basins, baths or tubs are slow to empty
  • Toilets overflow or fill higher than usual
  • Yard gully overflows when the toilet is flushed or when basins or baths are released
  • Sewer access pits overflow
  • Gurgling noises occur in sanitary drains

What should I do if I have a sewage overflow on my property?

If you experience a sewage overflow on your property call us immediately.

We will investigate to see if the problem in the mains. If the mains are clear and the problem in on your property, you will be advised to call a plumber. Shoalhaven Water maintain the Council mains, not internal plumbing lines.

What do I do if I experience a blocked sewer?

If you experience a sewer blockage call us before you call a plumber. 

We will investigate as the problem may be in our sewer mains. If the blockage is in our mains, we will clear the line at no charge to you. 

If the problem is not in the mains, we will advise you to contact a plumber. The owner of the property will need to pay their plumber for any work in the property to clear the line.

Causes of a sewer blockage may include:

  • Wet wipes, tissues, kitchen paper, and rags being flushed down the toilet
  • Rubbish, children’s toys, tennis balls, nappies, clothing, sanitary pads/tampons, cooking waste, sand, and other wastes not suitable for flushing into the sewer system
  • Tree roots infiltrating the property pipes
  • Crushed or flattened pipes that have been damaged
  • Pipes that have been laid poorly

How to prevent a blocked sewer

Only the 3 P’s should be flushed down the toilet – Pee, Poo and (toilet) Paper. 

Other ways to prevent a sewer blockage are:

  • Don’t put food scraps, oil or cooking fats down the sink as they can solidify when they cool and cause blockages. Instead wipe pans with a paper towel and throw it in the bin.
  • Don’t plant trees over the sewer pipes as the roots get in and cause blockages.
  • Don’t bury sewer access pits (manholes) under gardens, driveways or lawns.

Tree Roots & Sewers

A plant’s roots supply it with the food and water it needs to survive. However, problems will occur if a plant discovers its next meal is hidden in either your property or our sewer pipes. Root damage to sewer lines leads to clogged, overflowing, and slow-flowing drains, sometimes accompanied by a gurgling noise from the toilet. If a problem occurs in your property sewer it is your responsibility to have it fixed.
Root damage can also let stormwater into the pipes. During heavy rain, this extra water can overload the sewerage system causing it to overflow into our waterways and pollute the environment.

How to avoid damage to your sewer

Points to consider when planting trees:

  • Plant gardens and trees away from sewer lines
  • Avoid planting species which are likely to cause problems (see below)
  • Consult your local nursery or gardening guide to find out how large a tree or shrub will grow. A tree’s roots will generally extend about one and a half times the distance of the adult plants branches.
Depending on the age of your home Council may have a plan of your property’s sewerage pipes. Contact Shoalhaven City Council’s Development Services on 4429 3211 to find out more.

How to fix damaged sewer lines

If your house sewerage pipes have been blocked by roots you will need to get a licensed plumber to clear them. As well as removing the roots you should consider fixing the damage in a way which will minimise future problems.

  • Contact a plumber who will estimate where the blockage is located. 
  • Your plumber can recommend the best solution for your particular problem.
If you stop plant roots from re-entering your sewer lines you will save yourself the expense of having to keep on clearing them and you will also protect the environment by keeping stormwater out of the sewer.

Sewerage Access Points

Sewerage access points on your property are important and it is good to know where they are in the event of a blockage or overflow.

Boundary Risers are located close to the property boundary and sewer main and in the event of a blockage should be located and inspected by the owner of the property before contacting Shoalhaven Water or a plumber.

Yard Gully (sometimes known as an Overflow Relief Gully) is drain-like in appearance and located outside your house. They act to release sewage in the event of a blockage and are designed so that the loose fitting grate be free to ‘pop off’ completely allowing the sewerage flow that has backed up in the pipes to escape through the Yard Gully outside, rather than inside of your home or business.


A yard gully generally looks like this:

yardgully-large