Decline in tree canopy cover
Since measuring began, our City's tree canopy cover has decreased from a peak of 15.51% in 2008 to 14.28% in 2014 and further again to 13.84% in 2020 primarily due to the loss of trees on private property from infill development. Our tree canopy is currently lower than most local government areas in metropolitan Adelaide.
Our overall tree canopy is in decline and this Strategy aims to arrest this decline and provide a planned approach to reach our target of 25% cover by 2045.
The chart below demonstrates how our City has changed over time. We have measured the changes on private and public lands which, when combined, gives us a City-wide measure.
The three categories are:
- tree canopy cover - this is the measure of how much of the land is covered by trees;
- impervious cover - this is the measure of how much of the land is covered by buildings, driveways, paved courtyards, footpaths and roads; and
- plantable space cover - this is the measure of how much of the land could be planted with trees.
Trends across our City
This pie-chart shows how the City is covered by proportions of cover types.
With almost two-thirds of the City being impervious, this has impacts in relation to heat and stormwater.
Impervious surfaces tend to absorb heat during the day and radiate this heat at night, leading to urban heat islands. Impervious surfaces also act as a barrier to rain settling into the ground, and shed this water into the stormwater system, sometimes causing localised flooding.
When we plant more trees and increase canopy cover, this cools down the City and intercepts falling rain, lessening the effects caused by impervious surfaces.