Outdated Tree Management Practices: The Case for Smarter, Smaller Clearances

The primary reason trees in urban areas are pruned so severely is due to the current Code, which mandates a minimum clearance of 100cm between uninsulated low voltage conductors and any part of the tree at all times. This clearance must also account for regrowth, which is generally accepted to be an additional 100cm, resulting in a starting cut distance of at least 200cm.

The Working Group’s report emphatically demonstrates there is no need for such extensive clearance, as proven by practices in South Australia for over 40 years and more recently adopted in New South Wales. The Working Group has proposed that the minimum clearance be reduced to 30cm, which is still more than science requires. This change would allow trees to be trimmed to a starting point of around 130cm, preserving much more of the tree’s crown and delivering $1 billion in social, environmental and climate benefits.

TREENET supports increasing our tree canopy and advise:

“South Australia’s Electricity (Principles of Vegetation Clearance) Regulations 2021 prescribe smaller clearances than those enforced in Victoria, with lower voltage conductors in many areas not cleared unless they are distorted by branch contact. Asset and risk managers should be asking why Victorian arborists are still being placed at risk pruning clearances around lower voltage conductors when SA regulations have shown it’s not necessary.“

Comparing Tree Trimming: Proposed 30cm Clearance vs Current Standards

As an example, below is a typical street tree trimmed according to the proposed 30cm minimum clearance compared to the current Code requirements.

This tree is a Lophostemon, commonly known as a brush box, a typical urban street tree. Notably, the significant amount of vegetation removed can be seen scattered on the footpath beneath the tree.

Before Trimming

Proposed

Current

Common Questions About the Proposed Change in Minimum Clearances

  • Will workers be exposed to increased risk of contact with the conductors?
    No, because when trimming to a starting point of 130cm based on the proposed minimum clearance of 30cm, workers remain well outside their personal safety clearances. In other states where smaller clearances have been implemented, there have been no recorded safety incidents. All workers receive extensive training and use insulated equipment.

  • Will this affect the reliability of supply?
    No, small branches in contact with powerlines do not impact supply. This has been confirmed by the Municipal Association of Victoria (MAV). Click to read: Risk-based Managment Plan Field Manual

  • Will this increase costs to the community?
    No, as the trimming cycle will remain the same. In fact, in some cases, trees may require less frequent trimming, potentially reducing maintenance costs.

  • Will this make it more likely for people to climb the tree and be exposed to risk?
    No, as the smaller branches that remain closer to the powerlines will not support a person’s weight. Retaining these branches may actually deter people from climbing into the internal parts of the tree.

  • Will this improve the urban environment?
    Yes, emphatically. Retaining more of the tree’s foliage will enhance the urban environment, contributing to better air quality, cooler streets, and more habitat for wildlife. The City of Boroondara commissioned a report for submission during the last review of the Code in 2020, which clearly outlines the current situation. Click to read: ELC Regulations City Of Boroondara