Frequently Asked Questions

12. What trees and shrubs should I avoid planting near underground pipes?

Sewerage pipes are at greatest risk from the roots of plants because, unlike water pipes, they are unpressurised. Because of this, the roots of plants can quickly grow into the pipes if a crack or other fault occurs.

When planting, the aim should be to keep any medium to large trees well away from the pipelines. As a tree grows, its roots expand and thicken and this causes stresses within the soil. If a sewer pipe is in the vicinity, the stresses can cause compression or movement of the pipe, leading to cracks or broken joints. Once the integrity of the pipeline is broken, any plants, even grasses, can cause blockages.

All trees and many large shrubs are a potential risk to sewerage pipes so they should be planted at least 4 metres away from the pipe's alignment. The trees and other plants listed below are common examples of species with particularly vigorous root systems and they should be at least 10 metres from underground pipes. Note, however, that the list is not comprehensive - for further information refer to the Fact Sheet published by Western Water, Victoria.

Know what's underground before planting!!

Trees with very vigorous root systems

Botanical Name Common Name Botanical Name Common Name
Acer negundo * Box elder * Allocasuarina and
Casuarina species
She oaks, river oak, forest oak
Angophora species Large species Araucaria species Hoop, bunya and Norfolk pines
Castanospermum
australe
Black bean Corymbia species Large gum trees
Eucalyptus species Large gum trees Ficus species Figs
Grevillea robusta Silky oak Jacaranda mimosaefolia * Jacaranda *
Liquidambar
styraciflua
*
Liquidamber * Lophostemon confertus Brush box
Melaleuca
quinquenervia
Broad-leaved paperbark Melaleuca styphelioides Prickly paperbark
Platanus acerifolia * Plane tree * Populus species * Poplars *
Quercus species * Oaks * Salix species * Willows *
Schinus molle * Pepper tree * Schefflera actinophylla Umbrella tree

* indicates an exotic species


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