What has Council already done to try to resolve the issue?
Council has undertaken extensive investigations over several years, including:
- Footpath and driveway works (October 2021) to reduce surface impacts
- Ongoing monitoring and maintenance pruning (August 2021, March 2023, February 2024)
- Arborist assessments by two Council and two independent experts
- Investigation of root barrier installation (Council’s preferred option)
- A detailed root mapping investigation (late 2025), commissioned by the resident and reviewed by an independent arborist as well as Council’s arborists
- Independent review of the root mapping and risk assessment
These works aimed to reduce impacts and identify a safe way to retain the trees but did not resolve the underlying root issues.
What did the root investigation find?
The investigations confirmed:
- A large number of significant roots extending into the neighbouring property
- Root sizes ranging from approximately 70mm to 300mm
- At least 17 major roots identified within the investigation area
- Many roots are structural and critical to tree stability
Further analysis found that:
- Root pruning for a barrier would require up to 60% encroachment into the root system
- The trees would likely not remain viable following these works
- A formal risk assessment identified a high risk of tree or branch failure
Was the root barrier option properly investigated?
Yes.
Council initially pursued a root barrier as the preferred solution and has successfully used this method at other locations in Lane Cove.
However, at this site investigations confirmed that:
- Installation would require removal of multiple structural roots
- These roots are located within critical root zones
- The extent of root loss would significantly impact tree stability and health
As a result, a root barrier is not feasible at this location.
Why can’t the roots just be pruned?
To prevent further property damage, the impacting roots would need to be removed.
However, all arborists agreed that removing roots of this size and location would:
- Compromise the structural stability of the trees
- Significantly reduce their health and life expectancy
- Prevent sufficient regrowth
- Create a high likelihood of tree or major branch failure
Did independent experts inform Council’s decision?
Yes.
Four qualified arborists — two Council arborists and two independent arborists — assessed the trees. All reached the same conclusion:
- The required root pruning would unacceptably damage the trees
- The trees would present a high safety risk
- There are no reasonable alternative options to safely retain the trees
Were other options considered?
Yes. Council and independent arborists assessed a range of options, including:
- Root barriers (preferred option)
- Selective root pruning
- Partial interventions
- Removal of a single tree
- Ongoing monitoring
All options were found to be ineffective, temporary, or to create unacceptable safety risks.
Why is removal now the preferred option?
Removal is the only option that:
- Addresses the ongoing structural damage
- Avoids creating a high safety risk
- Provides a long-term solution
It is considered a last resort after all other options were explored.
Why can’t one tree be retained?
Options including removal of a single tree were assessed.
However, due to the extent and location of the root systems, partial removal or intervention would not resolve the issue and would still present safety and structural risks.
What happens next?
- Council will observe a 28-day notification/consultation period
- Tree removal works will be scheduled following this period
- Traffic and pedestrian management will be in place
- Impacted residents will be contacted prior to works
Will the trees be replaced?
Yes.
Council is committed to maintaining the urban canopy. Replacement trees will be planted with species selected to:
- Provide long-term canopy benefits
- Reduce the risk of future structural impacts
Council welcomes community input on suitable replacement species.