Unley Council set to move ahead with plan to charge higher rates for new, larger developments that don’t keep enough trees
One Adelaide council wants to slug some homeowners higher rates if they don’t keep enough trees on their newly developed property.
Unley Council is forging ahead with a “globally unique” plan to charge higher rates if some new developments fail to keep enough trees, in a bid to maintain its leafy suburbs and avoid extreme temperatures.
On Monday night, it voted to seek state government permission for a 10-year trial of its tree offset incentive scheme after a positive reaction from the community.
It would increase rates by 10 per cent for all new developments that take up extra land – about 220 a year – but fail to keep at least 15 per cent tree coverage, to “incentivise” developers to keep trees.
The council is on a tree-planting mission to meet the state government mandate of 31 per cent canopy cover by 2045 and lower future temperatures.
But it’s facing the net loss of an Unley Oval’s worth of trees annually because of planning rules, Mayor Michael Hewitson said.
It will run out of land to plant more trees by mid-2028.
The world-first trial acts as an incentive for developers to keep trees while raising cash for land.
Mr Hewitson said more than 60 per cent of 532 respondents supported the trial, while 73.5 per cent felt increase tree canopy was important.
However, council documents show “strong” opposition to the 10 per cent figure and feared it would change developer behaviour.
Data for the trial – eight years in the planning – showed suburbs without extensive tree canopies were significantly warmer, Mr Hewitson said, and creating poor health.
“One suburb in Sydney has 30 per cent tree canopy and the next-door suburb has 10,” he said.
“You’re talking the difference in temperatures in 50 degrees for the suburb with 10 per cent, and 10, 12 degrees less.
“Once you lose your trees, you start trying to plant trees and when the temperatures go into the 50s, how many trees are going to survive?”
The plan – which requires the Planning Minister’s approval – would affect only new developments and not be retroactive.
If a property hit 15 per cent tree canopy – routinely monitored by council’s heat-mapping service – the surcharge would vanish. Trees must be least 3m in height, and ratepayers could plant what they want. Prospective buyers would be warned of the extra rates.
Developments with no space for trees would not be exempt.
Mr Hewitson argued the trial would not push up house prices or deter people from moving to Unley, because its rates were lower than surrounding councils by 14.7 per cent.
“So they’re still 4.7 per cent cheaper to live in Unley, even if you’re paying the 10 per cent incentive to comply,” he said.
“Any development that uses up extra land is making a choice whether to use some of that land to plant trees on – or whether to build on it. Trees add value to the resale.”
Property Council SA head Bruce Djite said Unley’s proposal risked making housing less attainable without improving tree canopies.
He said it would penalise residents doing “minor” developments on smaller lots who could never meet the 15 per cent target and tree protection was already embedded in SA planning code.
“The last thing our planning system needs is a patchwork of inconsistent local schemes that confuse homeowners and developers when we are in the midst of a housing crisis,” he said.
Mr Hewitson said the plan would create a more liveable future and could be taken up worldwide.
“That’s what’s at stake – this doesn’t affect just Adelaide, it affects cities around the world. If this works, it’ll change the global temperature.
Green Adelaide, which spearheaded the 30 per cent tree canopy strategy, said it supported “new and innovative ways to make Adelaide cooler, greener and wilder”.
The council will now write to Mr Champion seeking permission to start the trial.
