601 landslides in 2023 spur works to improve slopes

Hong Kong was hit by 601 landslides last year - nearly eight times of that in 2022, of which 181 occurred during the once-in-a-century rainfall last September.

Revealing the figures yesterday, the Geotechnical Engineering Office said it is conducting systematic investigations and studies on major landslides triggered by extreme rainstorms in recent years with a view to planning hazard mitigation measures.

Investigation has so far shown that most landslides were caused by overflow from streams, catchwaters or drains, including the severe landslide at Yiu Hing Road in Shau Kei Wan, GEO deputy head (Island) Lawrence Shum Ka-wah said.

"One of the largest boulders blocking the road was seven meters wide and the boulder clearing work took five to six months," he said.

"The emergency stabilization works are expected to be completed by the end of next month."

Maintenance work is needed in the long term to improve the safety of the road section, Shum said.

The GEO has also identified 500 slopes with adjacent sole access used by a considerable number of local residents, one to two percent of which require simple maintenance works to be completed by this month.

Shum expressed the hope that while they cannot guarantee there will be no landslide, the impact of landslides can be reduced through speedy response and cooperation with the public.

The office also introduced a special landslip advisory mechanism based on the rainfall in the past 24 hours, to remind members of the public of the landslide risk in areas experiencing persistent rains.

Shum said the advisory is a dynamic warning with no hard indicators as it would depend on various factors such as the extent of the impact of the rainfall and the number of slopes in the area.

Commenting on the landslide involving illegal structures at luxury estate Redhill Peninsula in Tai Tam, Shum said they have inspected and identified unauthorized building works, and issued the relevant removing orders.

"The office will continue to provide professional advice," he said.

Meanwhile, the Development Bureau is seeking HK$9.5 billion to improve seven drainage systems in areas with serious flooding including Wong Tai Sin and the Eastern District, with a view to commencing the works from the third quarter this year for completion from the first quarter of 2028 to the third quarter of 2030.

A Legislative Council document shows that the Drainage Services Department planned to construct an underground storm-water storage tank with a capacity of about 47,000 cubic meters in Morse Park and rehabilitate the existing drainage system of Po Kong Village Road to mitigate the risk on Wong Tai Sin, one of the hardest-hit areas by flood last September.

Subject to funding approval by the Legco, the works are expected to be completed in phases over five years.

stacy.shi@singtaonewscorp.com