FAQs

The City of Unley has been tracking tree canopy trends (increases and decreases) across public and private land using LiDAR (Light Detection and Ranging) technology since 2018. 

LiDAR data demonstrates that there has been a 1.36% increase in total canopy cover on public and private land combined between 2018 and 2021, bringing the City of Unley’s total canopy cover to 27.99%. It also shows that tree canopy loss occurs on private land at a 2-3 times higher rate than on Council land. 

Growth of existing trees has contributed five times as much to new tree canopy cover than newly planted trees from 2018-2021, and while some new trees are being planted, we can see that trees are being removed at a faster rate than what they are being planted.

The State Government has set a target to increase urban green cover by 20% across metropolitan Adelaide by 2045 in recognition of the many benefits of green cover to urban cooling, local character, physical health, mental health and the biodiversity and liveability of our suburbs. 

To achieve this target, the City of Unley would need to increase tree canopy cover by 0.74km2, taking total cover in the City of Unley to 31%. 

The City of Unley has an active tree planting program in place, however Council owned space available for tree planting is limited, and at the current rate of planting, there will be no Council land available for tree planting left by 2026. 

80% of land in the City of Unley is privately owned, so to achieve the 31% canopy cover target, canopy cover on private land needs to increase either via the growth of existing trees or the planting of new ones.  

Trees are removed for numerous reasons, including disease, maintenance, lack of knowledge around tree care and more. 

However, the largest and most significant loss of tree canopy is due to increased urban infill and lifestyle developments on private land. This includes large-scale high density housing developments and a preference for large home footprints with low maintenance landscaping and double car garaging.  

These preferences result in a loss of gardens, reduced open space, and a propensity to clear a whole block of vegetation prior to redevelopment, placing established trees on private land at risk. 

The image below shows tree removal due to renovations on private land.

Most decisions relating to tree removal on private property are at the property owner’s discretion, however Council approval is required to remove a ‘significant’ or ‘regulated’ tree.  

Amendments made to the legislation since it was introduced in 2006 have resulted in some exceptions to this rule. 

In 2011, a significant number of trees, both exotic and native, were declared exempt from tree protection laws due to their species type and/or distance to a dwelling or swimming pool.  

In 2017, public schools and the Department of Infrastructure and Transport were made exempt from tree protection laws.  

Decisions relating to the protection of significant trees on projects that have been declared major developments has also been removed from Council.

A ‘regulated tree’ is:  

A significant tree is: 

Planning assessments are undertaken in accordance with the policies and guidelines of the Planning & Design Code, which is administered by the Minister for Planning under the Planning, Development and Infrastructure Act 2016.  

The Code outlines an Urban Tree Canopy Overlay in South Australia and declares a list of significant trees state-wide, however all the Code provisions are advisory, not mandatory requirements.  Where an overlay applies (like the urban tree canopy overlay), then due consideration and weight is given to the provisions when assessing a development application. 

Any changes to the Code require the approval of the Minister.   

A council or a private person can propose to amend the Code (such as rezoning land) by a Code Amendment but approval to proceed with the proposal (for community consultation) and with implementation can only occur with the Minister’s approval. 

A council (and the LGA for matters of general local government interest across the state) can lobby for changes to the planning system.

You can support the work that Council and the State Government are undertaking to increase tree canopy by maintaining and growing the existing trees in your gardens wherever possible or planting/replanting new trees. 

You can also suggest ways that Council could support you to increase tree canopy in your gardens via our ideas board and /or complete our survey as part of this Shaping Unley Consultation.

LiDAR technology is a remote sensing method that uses laser reflections of ground and other surfaces of the earth to provide high resolution topographic mapping. These reflections are used to make a digital three-dimensional image of objects on or near the ground, such as buildings, roads, and trees. 

The resulting data can be used to model tree canopies, including tree heights and canopy boundaries. 

The City of Unley developed a digital change detection program Using the 2018 and 2021 LiDAR datasets, allowing canopy changes to be mapped to individual property levels using LiDAR technology, and overlayed with building development and tree maintenance datasets. 

This data has provided an excellent understanding of the changes to tree canopy in the City of Unley, and the specific factors that have led to these changes. 

You can view canopy changes at individual property levels using the MyCanopy app at mycanopy.unley.sa.gov.au