• Tree failure incidents have dropped from 3,100 in 2000 to 339 in 2020, Minister of National Development Desmond Lee said 
• Regular tree inspections are carried out every six to 24 months, he said
• Trees that are found to have possible defects are subjected to an additional in-depth inspection

SINGAPORE —  The number of incidents of tree failure — the structural deterioration or breakage of any part of a tree — has tumbled by almost nine-fold over the last two decades, from 3,100 in 2000 to 339 in 2020, Minister of National Development Desmond Lee said on Wednesday (March 3). 

Speaking in Parliament, he said this was thanks to the National Parks Board’s (NParks) comprehensive tree management programme.

“However, it is not possible to completely prevent tree-related incidents because trees are living organisms that can be affected by pests and diseases, as well as environmental conditions,” Mr Lee said.

Even healthy and structurally sound trees can fall during storms, due to exceptionally strong winds or heavy rainfall, he added.

Mr Lee was responding to a question by Member of Parliament (MP) of Jurong Group Representation Constituency (GRC) Shawn Huang on how NParks ensures that trees in public areas are safe from tree rot, infestation and tree failure that can potentially cause a loss of life.

Mr Huang had also asked whether there were sufficient resources allocated to conduct these inspections and what scenarios would cause a healthy tree to fail within nine months after its inspection.

Last month, a woman was killed after she was trapped under a fallen tree at Marsiling Park on Feb 18. NParks later said that it had last inspected that particular tree in April last year.

“We deeply regret the loss of life. Every one death or injury as a result of tree fall incidents is one too many and my colleagues at NParks and the arborist community work hard day after day to keep our streetscape, our parks and our nature areas safe for Singaporeans to enjoy and will continue to press on, to keep up the work and to ensure that our nature is safe and enjoyable for everyone,” said Mr Lee.

MP for Marsiling-Yew Tee GRC Hany Soh asked how frequently NParks checks its trees.

Mr Lee answered that regular tree inspections are carried out by trained inspectors every six to 24 months. Trees that are close to areas with high pedestrian or traffic activity are inspected more frequently.

During a tree inspection, NParks’ inspectors examine its crown, branches, trunk and roots, and trees that are found to have possible defects are subjected to an additional in-depth inspection.

Since November 2016, in-depth inspections are also conducted annually on trees of more than 4m in girth as a precautionary measure in response to changing weather conditions, he said.

NParks has also put in place measures to reduce the risk of tree failure, including carrying out targeted arboriculture treatments to improve general tree health and their ability to withstand severe weather conditions, Mr Lee added.

NParks prunes trees regularly to remove weak, dry or overgrown branches, and to improve their structure and balance. It is also progressively replacing storm-vulnerable tree species with hardier species, he said.

NParks also uses technology such as modelling techniques to analyse risks and improve inspection processes, he added.

Ms Soh also asked Mr Lee whether there is a safety check regime for parks under NParks’ charge.

Mr Lee said that NParks appoints registered professional structural engineers to inspect the structural integrity of buildings and structures in its parks, such as shelters, bridges and monuments, once every five years. 

Regular and systematic checks of park facilities are also conducted by NParks staff and external inspectors, said Mr Lee.