SINGAPORE – Parts of the trails at Telok Blangah Hill Park have been closed for repair till July 2026 after a slope failure.
In response to queries from The Straits Times, National Parks Board (NParks) group director for parks Chua Yen Ling said heavy and prolonged rain on Feb 28, 2023 caused a slope failure at the park’s elevated Forest Walk.
The affected parts of the trails closed for public safety and slope repairs include the eastern section of the Forest Walk and Earth Trail.
“The (repair) works are necessary to stabilise the slope and strengthen the foundation of the elevated walkway,” Ms Chua added.
During the closure, park visitors can use an alternative path along Telok Blangah Heights to continue their exploration of the Southern Ridges.
NParks was not able to comment on when the decision to close part of the trails was made, when queried. However, an advisory from the agency, dated Jan 11, 2024, can be found online.
A slope failure refers to a collapse or failure of a sloping surface usually due to weakening of underlying materials like soil or rock, said National University of Singapore (NUS) senior lecturer of geography Dr Muhammad Nawaz.
Heavy rainfall can saturate the soil, destabilising the slope and making it more prone to erosion. He noted that the added weight of water and increased pore pressure within the soil in hilly areas, where slopes are already inclined, can exceed the soil’s strength.
ST reported in March 2023 that the downpour a month earlier on Feb 28 was the heaviest over the eastern and southern parts of Singapore, with the daily total rainfall of 225.5mm in Kallang the highest on record for the month of February.
Not all slope failures can be considered as landslides, he added.
“While slope failure is a type of movement on a slope, it’s not always classified as a landslide unless it involves significant downward movement of materials,” he said.
To reinforce the slope and prevent further erosion, NParks could employ measures like earthwork and water management by installing drainage systems, said Dr Teo Tee Hui, a senior lecturer in engineering product development at Singapore University of Technology and Design.
He added that NParks can also put in stabilisation structures like anchoring, and install inclinometers to monitor the slope conditions. An inclinometer is an instrument used for measuring angles of slope, elevation, or depression of an object with respect to gravity’s direction.
NParks said it will replant suitable vegetation cover after the slope stabilisation is completed, and that it regularly carries out inspections of areas surrounding slopes within its parks.
It reminds the public to avoid entering parks, nature reserves and forested areas during and immediately after bad weather.