Pool removal near protected trees in the Southern Highlands adds an approval and planning layer that catches many owners off guard. Wingecarribee Shire’s tree preservation controls protect a wide range of species across the region, and excavation for pool removal can encroach on Tree Protection Zones and Structural Root Zones in ways that the approval conditions will not allow without an arborist’s assessment. Understanding the rules before you book machinery is far cheaper than a stop-work order or a complaint from council. Our full pool removal service always begins with a site inspection that includes a tree proximity assessment.
Wingecarribee’s tree preservation controls
Wingecarribee Shire Council controls tree removal and significant pruning through the provisions of the Wingecarribee LEP 2010 and associated Development Control Plan. The controls apply to trees above specified size thresholds and to trees specifically listed as significant.
The Wingecarribee Shire, tree management pages set out when approval is required and which species are covered. Key triggers include:
- Trees with a trunk diameter at breast height (DBH) of 100mm or greater in most zones
- Trees listed as significant in schedules to the DCP
- Trees within heritage conservation areas, where thresholds may be lower
- Native canopy trees on rural lots, even at smaller sizes in some cases
For pool removal purposes, the most relevant scenario is not removing trees, it is excavating within the protected zone around trees that you intend to keep. This is where the tree controls most frequently interact with pool removal work.
Structural Root Zone and Tree Protection Zone basics
Two key measurements apply under AS 4970, protection of trees on development sites, which is the standard Wingecarribee Council references for tree protection during construction.
Tree Protection Zone (TPZ): The area around a tree where ground disturbance, vehicle movement and soil compaction are prohibited or restricted. Calculated as 12 times the trunk DBH in metres (e.g. a 300mm DBH tree has a 3.6 metre TPZ radius).
Structural Root Zone (SRZ): The area immediately around the trunk where structural anchor roots are concentrated and where root cutting or severing will compromise tree stability. Smaller than the TPZ, calculated as 50% of the TPZ radius.
| Tree trunk DBH | TPZ radius | SRZ radius |
|---|---|---|
| 100mm | 1.2m | 0.6m |
| 200mm | 2.4m | 1.2m |
| 300mm | 3.6m | 1.8m |
| 400mm | 4.8m | 2.4m |
| 600mm | 7.2m | 3.6m |
A large, established oak or liquid amber with a 500mm trunk, common on Highlands properties settled in the late nineteenth or early twentieth century, has a TPZ extending 6 metres from the trunk. If a pool is within 6 metres of such a tree, the excavation for removal will intrude into the TPZ.
When you need an arborist report
An arborist report is required when the pool removal scope involves any of the following:
- Excavation within the TPZ of a protected tree
- Machinery access routes passing through the TPZ
- Root cutting or severing of roots above 50mm diameter during excavation
- Removal of any tree affected by works, where that tree triggers the approval threshold
The arborist report sets out the condition and significance of the affected trees, the likely impact of the proposed works, and any mitigation measures such as tree-sensitive excavation methods, root pruning protocols, or fencing of the TPZ during works.
Wingecarribee Council typically requires this report as part of the development application or CDC application when tree impacts are identified. Arborist report fees for a residential pool removal context range from around $500 to $2,000 depending on the number of trees assessed and the complexity of the site.
Root-cutting rules during excavation
Not all root cutting is prohibited, but it must be managed. The general rules under AS 4970 and arborist best practice are:
- Roots less than 25mm diameter may be cut cleanly with a saw during excavation, provided it is not excessive
- Roots 25-50mm diameter should only be cut after consultation with the arborist
- Roots above 50mm diameter should not be cut without explicit arborist approval and usually a redesign of the excavation approach
- No roots within the SRZ should be cut without significant justification
Clean root cuts (with a sharp saw, not torn by a bucket tooth) heal faster and reduce disease entry points. Torn and split roots from excavator buckets are far more damaging to tree health.
When excavating near protected trees, the most effective approach is hand digging or air-spading in the sensitive root zone, with the mechanical excavator working from outside the TPZ. This is slower and adds cost but protects tree health and keeps the approval conditions intact.
Species commonly protected in the Highlands
The Highlands is well known for its mature exotic plantings, autumn colour from deciduous trees is a regional attraction, and many of these trees are large and protected. Species commonly encountered:
- English elm (Ulmus procera): Very common in Bowral and Mittagong gardens. Large root systems.
- Oak (Quercus spp.): Pedunculate and pin oaks, often planted as avenue or specimen trees.
- London plane (Platanus x acerifolia): Widely planted. Can reach enormous size.
- Liquid amber (Liquidambar styraciflua): Popular twentieth-century planting, common near pools.
- Native canopy trees: Spotted gum, Ribbon gum and Black wattle on rural lots and in conservation areas.
Heritage properties in Berrima and Sutton Forest often have significant plantings that predate the houses’ mid-twentieth century pool additions. On these properties, the heritage and tree protection frameworks interact, see our heritage listed pool removal guide and conservation area guide for those contexts.
Alternatives: partial fill-in to save a tree
When a full pool removal would require excavation through the SRZ of a significant tree, a partial pool removal fill-in can be the right answer. Rather than fully excavating and removing the shell, the pool is broken at the top, drainage holes are punched in the base and sides, and the void is filled with granular material without disturbing the root zone beneath.
This approach is accepted by Wingecarribee Council in cases where a full removal would compromise a protected tree. The arborist report will usually recommend this as the preferred option where root systems are densely concentrated beneath the pool floor.
Our partial vs full pool removal guide explains the structural and cost trade-offs. Where there are significant trees, partial fill-in is often not a compromise, it is the technically correct and council-preferred outcome.
Our guide to protecting your property during pool removal covers the physical tree protection measures used during works once approval is in place: TPZ fencing, vehicle exclusion, and root treatment after excavation.
Post-works tree monitoring
After a pool removal where excavation has approached or entered the TPZ, tree condition should be monitored. Signs of stress from root disturbance can take one to three growing seasons to appear fully. Look for:
- Crown dieback or leaf drop outside the normal cycle
- Bark cracking or stem damage near the base
- Unusual lean or ground subsidence near the tree
If any of these signs appear, a follow-up arborist assessment is worthwhile. Trees stressed by root disturbance during pool removal can recover with appropriate care, deep watering, mulching of the TPZ and avoiding further soil compaction, but early identification is important.
For your approval pathway questions, the Wingecarribee CDC vs DA guide explains how tree impacts can tip a pool removal from an exempt or CDC pathway into a full DA.
FAQs
How close can pool removal excavation get to a protected tree?
The general rule is that no excavation should occur within the Structural Root Zone without arborist approval, and that works within the Tree Protection Zone require an approved arborist report first. For a tree with a 300mm trunk, the SRZ extends about 1.8 metres from the trunk and the TPZ extends 3.6 metres. Larger trees have proportionally larger protected areas.
Do I need an arborist report for every pool removal near a tree?
Not for every tree. A fast-growing ornamental shrub with a 100mm trunk that is not listed as significant may not trigger the threshold. An arborist report is needed when excavation will enter the TPZ of a tree that meets the council’s protected threshold. Your pool removal contractor should flag this at the site inspection.
Can I remove a protected tree to make pool removal easier?
Only with council approval, which is assessed on its merits. Convenience is not a sufficient justification for tree removal in most cases. Where a tree genuinely conflicts with pool removal and there is no feasible alternative, council may approve removal with conditions such as replacement planting of appropriate species and size.
What happens if my contractor damages a protected tree?
Damage to a protected tree during building works can result in an infringement notice from Wingecarribee Council. The owner and the contractor can both be held responsible. This is why an arborist report and compliance with its conditions is important documentation, it demonstrates due diligence if a dispute arises.
Is a partial fill-in accepted as an alternative where trees conflict with full removal?
Yes. Wingecarribee Council and most arborists will recommend a partial fill-in when full excavation would compromise protected root systems. Our partial pool removal fill-in service is designed for exactly this scenario.