Earlier this year, findings of a public inquest were released about a tragic accident caused by the fall of a tree in Hobart in 2014. We look into the pivotal role of tree risk management policies taken on board by the Tasmanian Government’s Department of State Growth.
On the afternoon of February 9, 2014 ‘wild weather’ from an intense low pressure system ripped into Hobart. A cold front brought ‘ferocious’ wind gusts in excess of 130kph, which tore off roofs, downed power lines, and caused the Hobart Cup to be called off. In the teeth of the gale, at the very moment a stem from a group of Black Gum (Eucalyptus Ovata) trees failed and toppled onto the Channel Highway, Brendan Smith was driving past. Tragically, the tree hit the cab of his ute and killed him instantly.
A Worm in the Apple Isle?
A three-day public inquest was held into the circumstances of Brendan Smith’s death by the Tasmanian Coroner’s Court in October 2018. The findings were published at the end of March and can be downloaded https://tinyurl.com/y5ce9zte.
How the Tasmanian State Government went about managing the risk from trees next to roads was put under forensic scrutiny by the Coroner, Olivia McTaggart. Though the Coroner found no evidence that there were any obvious defects in the tree, before it fell on that fateful afternoon, they were frustrated about the lack of clarity on how the risk from the trees had been managed since 2000. What had been done, when, and why was not clear. Olivia McTaggart’s conclusions were…
“The death of Mr Smith highlighted the need for a targeted and systematic process of assessing risks associated with roadside vegetation, especially trees.”
What’s a VALID Tree Risk?
On the very day the Coroner’s findings were released, I was flying into Hobart from the UK. The main reason for my trip was to help the Tasmanian Government’s Department of State Growth (DSG) with their approach to tree risk assessment and management, and to deliver training in obvious tree defect recognition to highways contractors.
Following Brendan Smith’s death, DSG had already put a lot of hard work into their draft ‘tree risk management framework’, but had found existing tree risk assessment systems cumbersome and unsatisfactory. The simplicity, clarity and integrity of VALID’s approach had come to their attention in 2018. After a meeting in Melbourne to discuss where they’d got to and where they could go, I was invited to come over and help them take their good work to the next level.
The Strategic Defence
Let’s step back from the DSG work for a moment. Whether you’re a government agency, landowner, a homeowner, if you own trees, then you’re responsible for managing the risk from those trees. Perhaps, the most important lesson from the Coroner’s findings is how critical it is to have a robust tree risk management strategy.
The central document in any tree risk management strategy is the policy. That’s because the policy is a position statement which sets out the grounds of how and why you’re going to manage the risk from your trees. Not only that, in the unlikely event of a tree failing and causing injury or death, and a legal claim is made, it maps out the territory on which a solid defence could be built. Everything follows from this core document because it establishes the context. Without a policy, if someone is seriously injured or killed from a tree failing, then the duty holder is already on the back foot.
Here’s the headlines of a sound tree risk policy. Trees provide many important benefits that we need. The overall risk to the public is extremely low. You can’t completely remove the risk, and some trees may fail during severe weather. You have a duty of care, but that duty also says that you should be ‘reasonable’, ‘proportionate’, and ‘reasonably practicable’. What those italicised words mean is, there’s a balance you should look to strike between the many benefits trees provide, the risk from them, and the costs of managing the risk. Finally, you’re going to manage the risk from your trees to an acceptable or tolerable level – you’re not trying to minimise or eliminate it
The Devil in the Tasmanian Detail DSG are responsible for over 3700 km of roads and millions of trees. The main aim of a tree risk management strategy is pretty easy to explain, as we’ve already discussed. It’s to manage the risk from tree failure to an acceptable or tolerable level. The tricky part is how do you go about assessing thousands of kilometres of road and millions of trees in a reasonable, proportionate, and reasonably practicable way? What are you using to measure the risk? How often do you do it? Who does it? How much is going to cost?
The solution is refreshingly straightforward. Using a combination of ‘Active’ and ‘Passive’ assessment, you carry out an Active assessment in high use zones, with large trees, at an agreed frequency. Five years is proposed as reasonable starting point, and is widely accepted. In other words, one fifth of trees in high use zones are assessed every year. Now, really importantly, Active assessment is continually topped up by Passive assessment. Passive assessment simply means staff keep an eye out for obvious defects they can’t help but notice as they go about their day-to-day routine. On top of this, the public are also encouraged to highlight trees that might be dangerous.
During VALID’s tree risk training tour this spring, I’m heading back to Hobart to continue working with DSG on finishing off their strategy. How DSG are managing tree risk on their roads is of enormous interest to other Australian States, and New Zealand’s Transport Authority. These tree risk management conundrums are not unique to the antipodes. Other countries are also keeping a close eye to what the final product will look like. When it’s ready, we’ll be happy to share it.
Your Free Tree Risk Management Strategy
As a non-profit organisation, part of VALID’s mission is to share its publications. So, copyright has been waived and they’re all released under a creative commons license. Whether you’re a Government Agency with thousands of trees, a landowner with hundreds, or a homeowner with just one tree, VALID can help you with common sense tree risk management.
On the ‘Risk Management’ page of the website – www.validtreerisk.com/tree-risk-management-strategy-policy-&-plan – you’ll find there’s basic tree risk-benefit management strategies for Government, landowner, and homeowner that you’re welcome to.