Brisbane council fails to keep hundreds of thousands of trees in good condition raising risk of damage to property

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3 days ago

Brisbane's council failed to keep hundreds of thousands of its trees in good condition, raising the risk of damage to property or infrastructure, an internal review shows.
The council review, obtained exclusively by the ABC, divulged the number of good-condition trees on streets had slunk far below government targets and almost 20,000 trees had been in poor shape.
"Healthier trees reduce risk (e.g. from limb failure, insurance claims)," the review said.
It said council inspections might also have underestimated how many streetside trees were truly in poor condition.
Bureaucrats also described extreme pressure on tree maintenance budgets.
"Any further reduction in funding will likely translate to an increase in risk," they wrote.
The council's Asset Management Plan was completed in May last year. It was obtained in an ABC right to information request into high-level vegetation-management assessments in the two years before Cyclone Alfred smashed the state's south-east.
The cyclone's winds and heavy rain triggered almost $1 billion in insurance claims and cut power across 450,000 Queensland homes and business.
Council declined an interview request but in a statement rejected that problems with trees exacerbated cyclone damage.
"Brisbane coped extremely well in the challenging and unique circumstances."
Foliage crashing into powerlines is a common cause of electricity outages — Energex linked 42 per cent of blackouts in Cyclone Alfred to vegetation.
Energex's parent company Energy Queensland must remove vegetation posing an immediate threat to the electricity network.
It has maps coloured red for clearance zones around powerlines, dictating at least two metres' space between foliage and bare wires. It also must risk-assess potentially unstable branches above powerlines.
For areas outside its immediate cutting zones, Energex consults with private landowners or councils.
Falling branches during Cyclone Alfred damaged suburbs such as Brisbane's Chapel Hill.
Resident Tamami Kawasaki said a branch had plummeted on a powerline and praised Energex's response. "They quickly turned up and they tried to solve the problem," she said.
Still, she pointed to branches of other nearby trees that were a concern.
Also in Chapel Hill, Paul Erbacher's home lost electricity for almost six days when a big tree fell across the road several houses down and into a powerline.
That was outside the immediate danger zone for Energex's program. But Mr Erbacher pointed to a roadside tree near his home where the branches were "hitting the line". He said he had spoken to both Energex and council about it.
Both organisations had cut lower branches, but some higher heavy branches remained, he said. "It could cause a problem," he told the ABC.
Energex said it removed about 10,000 at-risk trees annually and cleared areas around powerlines, including in Chapel Hill.
"We also have to strike a balance between network reliability and community concerns around tree removal," Energex added.
Energex documents obtained by the ABC said vegetation clearance work around powerlines was at 98 per cent of its target in its southern district urban areas, incorporating heavily hit parts of the Gold Coast and southern Brisbane.
Only 76 per cent of work had been completed in rural areas.
Energex linked shortfalls to earlier heavy rainfalls and warmer weather increasing plant growth rates, and making work conditions dangerous in tough areas such as mountains.
It added field staff believed vegetation from outside designated cutting zones was a major outage factor, with cyclonic winds tossing foliage "hundreds of metres".
"Additionally … you have old growth gums more than 40 metres tall falling from well outside the trimming profile corridor, from people's front yards and public land, and bringing down powerlines," an Energex spokesperson said.
There is an historical precedent to poorly handled vegetation programs worsening damage: a 2004 state inquiry found energy supplier Energex cutting back on vegetation work amplified blackouts.
Brisbane council alone has an estimated 575,000 trees on urban streets, and its own review flags an inherent risk of a council-overseen trees damaging property.
Of the 411,000 street trees council assessed, the review's experts grouped together 74 per cent of them in the lowest three of five categories: dead (0 per cent), poor (5 per cent) or fair (69 per cent).
A tree in poor or dead condition is generally "removed" and the definition of "fair" condition includes less than one-third of the tree being dead.
The review warned the number of "fair" trees imposed a "maintenance burden and an increase in risk if these trees were allowed to deteriorate".
The "desired condition" would place the "majority" of trees in the top two categories, good and excellent, it said.
But only 26 per cent of trees met these top two categories, despite the "desired" level being 58 per cent in February 2024. The report stated improving tree conditions would "protect residents, staff".
Tree assessments occurred between 2016 and 2023, but the review flagged "historic audits may have under-represented trees in poor condition".
Only one-fifth of park trees in the 22,575 checks were assessed as being in good condition, but the sample examined was too small to be statistically significant. Most were in the "fair" category; 8 per cent were "poor".
In 10,988 "road-landscaping" areas, which can include median strips, 35 per cent of vegetation was in the top two categories, which was better than the targeted level of 25 per cent.
Council redacted details of associated public liability claims in the RTI documents, but noted tree roots caused many claims.
The review warned tree maintenance programs were "first to be cut as budgets were tightened and extreme weather events trigger increased reactive maintenance".
Maintenance budgets were $38.4 million in the 2023 financial year, lifted to $43.9 million in 2024 and slimmed in the current year to $42.5 million, it said.
Another problem it highlighted were financial black holes: new items were not being costed or projects including the airport arterial road, Kingsford Smith Drive, were "handed over with no maintenance budget" after an upgrade.
Council's public relations team referred the ABC to a "trimming budget" — a measure not used in council's review. Council spent $20.1 million on trimming in 2021, increasing to $25.8 million in 2024, it said.
Council's spokesperson said 95 per cent of Brisbane's 750,000 trees were in category three, "fair", or better condition. The public relations team has lumped category three with the top two categories, despite the review experts doing the opposite.
Council refused to answer many questions by the ABC and argued some of the review data was dated.
An ABC review found Energex slashed annual plant-clearing budgets by tens of millions of dollars in the past 10 years.
That comes after a government review in 2004 — following storm outages of more than 120,000 customers — finding damage could "have been avoided with adequate expenditure on vegetation management".
In 2005, Energex allocated $35 million to vegetation management; rising to $79.2 million as of 2012, the last year amounts were publicised.
Accounting for inflation, if 2012 expenditure levels were maintained, the 2024 vegetation budget should have been $108 million. But the actual spend that year was $46.2 million, Energex said.
Energex maintained expenditure cutbacks were justified because money was more efficiently spent on contractors, problem trees had been earlier removed and powerline protections improved.
Other councils in Cyclone Alfred's path generally backed their vegetation management programs.
The Gold Coast also did not answer some queries, but maintained it had proactively inspected 19,000 trees following a wild 2023 Christmas storm, identifying 600 for removal.
Redlands and Moreton councils said high-risk tree management or vegetation programs were running on track.
"Mitigating the risk of any tree within the local government area falling on powerlines would, in theory, require the removal of all trees with the potential to impact the network. This would eliminate the many environmental, social, and economic benefits provided by our urban forest," Moreton council said.
Logan council, though, said earlier storms in December 2023 had "set our tree maintenance program back by over 12 months" and was reviewing policies.