Tree roots in pipes and foundations

Published 25 August 2026 · Updated 13 October 2026

Roots in sewer and stormwater pipes

Coliban Water, which runs Bendigo's water and sewerage, says "tree roots can intrude into pipes, catching oils and rubbish", reducing flow and causing costly blockages. Signs of a sewer blockage it lists include:

• Toilets or drains that are slow to empty
• Bubbling or gurgling noises from drains
• Overflow from your plumbing or from the overflow relief gully outside

Older homes, common across central Bendigo, often have earthenware drains with many joints, and big gums or other thirsty trees in the yard. A plumber or drain cleaner can clear the roots and run a camera down the line to find the entry point. Clearing alone is a short-term fix if the joint stays cracked.

Your pipes or Coliban Water's?

Coliban Water says it looks after "sewer mains and house connection branches (HCB) up to 1 metre inside the property boundary". The property owner is responsible for "internal plumbing, septic tanks and pipes within the property boundary".

So roots in the pipe under your back lawn are usually yours to fix. If your plumber finds the problem is in the house connection branch, Coliban says a plumber who isn't on its inducted register must contact Coliban to ask whether it can charge Coliban for the work. If you're not sure where the problem is, Coliban is on 1300 363 200.

Roots and house footings

Clay soils swell when wet and shrink when dry. Building sites are classed by how reactive the soil is, from A (non-reactive) through S, M, H1, H2 and E, with P for soft soil or fill. The Building and Plumbing Commission, Victoria's building regulator, says "the more reactive the soil, the greater the possibility of excessive movement in the footings of the house", and lists "tree roots growing under footings" among the causes of foundation movement. Trees draw a lot of water from the soil, so a big tree close to the house can dry the clay under one side of it.

The commission's guide to cracking:

• Cracks more than 5 mm wide "are considered significant and outside the tolerances for footing movement"
• Cracks between 1 mm and 5 mm should be monitored over a full year
• Bulging walls and doors or windows that stick or distort can be signs too
• For significant movement, the cause "should be further investigated by an endorsed civil or structural engineer"; if the home is under 10 years old, start with the builder

Does removing the tree fix it?

Sometimes, but not on its own. Roots already in a pipe still need clearing and the pipe still needs repairing, and stump grinding removes the stump, not the roots, which rot away over years. Under a house on reactive clay, the commission's advice is to keep the foundation soil from "significant moisture changes". Taking out a large, established tree changes the soil moisture too, so on a cracked house get the engineer's view before the tree comes down, not after.

Removal also has to be allowed. A large tree can need a permit under the state native vegetation rules, the canopy tree rule in residential zones, or an overlay; the permit guide shows how to check. Other options include root barriers, relining the damaged pipe, or pruning the tree to reduce its water demand. When removal is the answer, see the published tree removal prices, and grind the stump if you're replanting nearby (grinding vs removal).

When the roots are from a neighbour's tree

The Victorian Government's guidance says "you have the right to cut back any branches, leaves, or roots that cross your property boundary line at your own cost", but you're liable for damage you cause to your neighbour's tree. Cutting major roots can destabilise a tree, so get advice first.

Where roots have damaged your property, the same guidance says your neighbour may be liable. Check your insurance, then gather evidence, such as an arborist's report, photos and repair quotes, and talk to your neighbour. The neighbour's tree guide covers the next steps, including free mediation.

Planting the next tree

Coliban Water's advice is to find out where your pipes run before planting, plant a safe distance away, check council's nature strip requirements and choose suitable species. The building regulator says to plant new trees "away from the house to allow for root growth".

Questions about tree roots in pipes and foundations