Unley Council moves ahead with plan to levy higher rates on new developments without enough trees

An Adelaide council will charge higher rates for new homes that don’t include enough trees as it runs out of space for more green canopy.

Unley Council is moving ahead with its dramatic push to force developers and new homeowners to plant more trees or face higher rates.

The council said despite an ambitious tree-planting scheme, it’s still losing 4ha of tree coverage yearly as developers remove trees – and will run out of its own tree-planting space by 2027.

Without action, it said, tree coverage across the once-leafy suburb will be just 12.9 per cent within two generations – down from its current 28 per cent, a far cry from the state government target of 31 per cent.

Now, in a “world-first” tree retention scheme, any new development that increases the “built form” would be levied an extra 10 per cent in rates until it had least 15 per cent tree canopy attached.

“There is a worldwide problem of councils planting trees and developers and homeowners chopping them down,” Unley Mayor Michael Hewitson said.

Unley mayor Michael Hewitson. Picture: Roy Vandervegt

“We planted 600 this year, more than 50 species – but by 2027 we won’t have any more room. And trees are still being pulled out. Half our loss is to new developments. So we finish up with 12.9 per cent tree canopy by the time the children of Unley are my age.”

The proposed 10-year trial requires permission from Planning Minister Nick Champion but no legislation change. The council will vote on Monday whether to take its plan – first announced in 2022 – to public consultation to “establish its case”.

“There will be problems in the trial – with some high-rise developments, you need to strip the block first, is it fair to hit everyone in a new block of units with a 10 per cent rate increase from the word go?” Mr Hewitson said.

“Some (high rises) along Unley Rd are just going upward – so they’re not increasing the built form.

An example of how Unley is mapping tree coverage.

“It may be for high-rise developments, we say it’s 3 per cent tree coverage for the first year and over the five years, it goes up to the 15 per cent.”

Council believes the 10 per cent level will change developer behaviour because it will be harder to sell homes that attract higher rates.

Any money would go into a fund for council to buy more land for more trees. Existing property owners are exempt from the levy. The council doesn’t intend to levy a homebuyer who purchases a new home with 15 per cent canopy, then fells trees.

“I suspect the people chopping them down, it’s to plant something else,” Mr Hewitson said.

“This is an incentive scheme – not a penalty.”

Potential home buyers would be notified if their new home did not have enough tree coverage and trigger the rate levy.

The scheme would be enforced by mapping technology already employed by council to gauge tree canopy levels across the city.

Unley has lost an average of 8ha of tree coverage in the ten years to 2018, with canopy cover dropping from 34 per cent to 26.6 per cent.

Council documents say that without action, the city will experience the same “50°C temperatures” that have hit western Sydney suburbs with less than 10 per cent tree canopy cover.

Temperatures on hot days will increase by up between 8-10°C, forcing residents to use more air conditioners.

Council would need to spend at least $54m a year to buy enough land and replace trees being lost on private property, causing 100 per cent increase in rates for all ratepayers.