Unitywater has identified tree root intrusion as the leading cause of wastewater pipe blockages across the Sunshine Coast, Moreton Bay and Noosa regions, revealing that one in five blockages recorded in the past financial year were caused by invasive roots.
New figures show field crews responded to 3,043 blockages in 2024–25, with tree roots responsible for 614 of them.
Unitywater’s Executive Manager of Customer Delivery, Rhett Duncan, said the problem was widespread and costly.
“Our data tells us Buderim, Clontarf and Caboolture are the suburbs with the most tree root blockages,” Mr Duncan said.
“We can see that 20 per cent of known blockage causes are tree roots. Other causes are fats, oils and greases, and foreign objects, which indicates the wrong items have been flushed or put down the sink.”
Duncan said tree roots naturally seek out water sources, often penetrating wastewater pipes and continuing to grow, eventually causing major blockages and overflows.
“These overflows can occur on private properties through overflow relief gullies and inside people’s homes through toilets and shower drains,” he said. “They create a smelly mess, an unpleasant clean-up and potentially expensive repair bills.”
Residents were urged to think carefully about what and where they plant, particularly as summer landscaping begins.
“If you have any landscaping plans over summer, check out Unitywater’s free online mapping tool to check for any Unitywater infrastructure on your property,” Mr Duncan said. “It’s also worth knowing where your private pipes run.”
Unitywater has also released a planting guide to help households choose species that are less likely to invade and damage underground pipes.
More information is available at Unitywater’s website.
