Planting over pipes and utilities – what you need to do first!
Planting over sewage and water pipes can be a tempting way to utilise space in your garden, especially in smaller or suburban blocks. However, it comes with serious risks. Tree and shrub roots can damage underground pipes, causing blockages, leaks, or even structural failures that are costly to repair. That’s why it’s essential to know what’s underground before you plant and to choose pipe-safe plants wisely.
Plants That Can Damage Pipes
Certain plants and trees have invasive root systems that are naturally drawn to moisture – and leaking or condensation-covered pipes are an ideal target. Over time, roots can infiltrate and break through joints and cracks, causing major plumbing issues.
Common plants and trees known for damaging underground pipes include:
Willow (Salix species)
Camphor laurel (Cinnamomum camphora)
Poplar (Populus species)
Rubber tree (Ficus elastica)
Weeping fig (Ficus benjamina)
Jacaranda (Jacaranda mimosifolia)
Liquidambar (Liquidambar styraciflua)
Chinese elm (Ulmus parvifolia)
Golden wattle (Acacia pycnantha)
Bamboo (especially running types like Phyllostachys species)
Avoid planting these species anywhere near sewer, stormwater drains, or water supply lines.
How to Find Where Pipes Are Located
Before planting anything significant, always check for underground utilities. You should never guess where pipes might be — one wrong dig could damage infrastructure or even cause injury.
Here’s how you can locate pipes safely and accurately in Australia:
1. Before You Dig Australia (BYDA):
This free service allows you to submit a request for maps of underground utilities like water, wastewater, and drainage mains. You can register online at BYDA and submit details of your dig site. BYDA then contacts relevant asset owners, and you’ll receive plans showing the approximate location of infrastructure on your property.
2. Water Corporation (WA specific):
The Water Corporation offers basic connection information via property searches. For sewer diagrams, you’ll still need to go through BYDA. For rules about building or planting near sewer mains, it’s best to contact the Water Corporation directly for guidance.
3. Other Location Methods:
Potholing: This involves manually digging test holes to expose underground pipes. If using mechanical equipment, you must have a Clearance to Work Permit and an Asset Protection Risk Assessment (APRA) from the Water Corporation.
Wire Tracers or Utility Locators: These electronic tools can detect pipe and cable locations underground.
Indirect Surveying: Ground-penetrating radar (GPR) and frequency resonating surveys can be used for complex or large-scale detection work.
4. Drainage Plumbing Diagrams:
You can obtain these through the Department of Water and Environmental Regulation. They show how stormwater and sewer pipes run within a property boundary.
5. Always Consider Safety and Compliance:
Working around underground utilities comes with legal and safety responsibilities. Always check for approvals and permits where required, and if in doubt, consult a licensed plumber or the utility provider directly.
Plants That Are Safe to Grow Over Pipes
If you’d like to plant over or near pipes, choose shallow-rooted, non-invasive plants that won’t seek out moisture aggressively.
Safer options include:
Liriope
Lamb’s ear (Stachys byzantina)
Dichondra
Violas and pansies
Clivia
Bergenia
Correa
Low-growing succulents (e.g., sedum or echeveria)
Dwarf agapanthus (Agapanthus praecox ‘Dwarf’)
Native grasses and groundcovers like Lomandra or Dianella
These plants are not only beautiful but generally pose a very low risk to pipes if maintained well and not planted in high densities.
In Summary
Knowing where your pipes are — and respecting that space — can save you major headaches down the track. Always check with BYDA before digging, and avoid planting species with aggressive root systems near water or sewer infrastructure. With the right planning and plant choices, you can have a safe, lush garden that won’t cause costly plumbing repairs later on!