A planning application that proposes either to remove protected trees or have an impact on trees on the site (and adjoining properties) requires a report from an arborist.
Australian Standard AS4970/2009 is the primary guidance for preparing arboricultural reports.
Here is a brief overview of the different types of arboricultural reports.
Preliminary tree assessment
The preliminary assessment of the trees should take place at the beginning of the project once any site surveys have been completed. The purpose of this assessment is to provide information on the trees health and condition.
All trees included in the site survey including adjacent properties should be numbered and assessed by the project arborist as the basis for deciding which trees are suitable for retention.
A preliminary tree assessment:
- provides information on species, origin, dimensions, health, and structure
- identifies tree protection requirements in accordance with relevant planning controls
- sets a tree protection zone (TPZ)
- sets a structural root zone (SRZ).
The preliminary report is intended to be used by planners, architects, and designers, in conjunction with any planning controls and other legislation, to develop and guide the design layout in such a way that trees selected for retention are provided with enough space.
Arboricultural impact assessment
The arboricultural impact assessment is prepared once the final layout is complete. The report will identify trees to be removed, retained, or transplanted, and identify impacts on trees to be retained.
The report explains design and construction methods proposed to minimise impacts on retained trees where there is encroachment into the calculated TPZ. It will recommend measures necessary to protect the trees throughout all demolition and construction stages.
The report will include a tree protection plan (drawing) showing the TPZs and SRZs for trees being retained. A copy of this plan will form part of the development plans. The tree protection plan should be included in subsequent construction documentation.
The location of tree protection measures should also be shown on other documents such as demolition, bulk earth works, construction and landscape plans.
This is the type of report we typically require for planning applications.
Tree protection and management plans
The approved tree protection plan must be available onsite prior to the commencement of and during works. The tree protection plan will identify key stages where monitoring and certification will be required.
A pre-construction meeting should be attended by the site manager, the project arborist, and contractors to introduce the tree protection plan and its requirements.