Engineers said on Monday they will carry out further inspections and maintenance of drainage systems on 1 to 2 per cent of the slopes by the end of this month in an effort to minimise the risk from rainstorms.
The news came as Legislative Council papers, in a related development, revealed that that the estimated HK$8 billion (US$1.02 billion) budget allocated to pay for improved drainage in some districts had gone up by 18.7 per cent to HK$9.5 billion.
Lawrence Shum Ka-Wah, the deputy head of the Geotechnical Engineering Office on Hong Kong Island, said staff would prioritise man-made and natural slopes where problems would have greater impact on people’s lives, such as sole access points.
“Around 1 to 2 per cent of the 500 slopes needed maintenance work, including ones of Shek O Road, South Lantau Road, New Clear Water Bay Road and so on,” he said.
He highlighted that illegal work or unauthorised construction on slopes, including at Redhill Peninsula in Tai Tam, posed safety risks.
Half of the homeowners at Redhill Peninsula were found to have illegal structures after what the government said was a “once-in-500-years rainstorm” last September caused landslides.
Shum said that unauthorised structures in the area were under investigation by other authorities.
The department has also improved its early warning system for landslides with the launch of an alert advisory system earlier this month.
“When heavy rain persists in certain areas yet not reaching the landslip warning level, the department will issue a special advisory to list areas with higher risks to alert the public,” Shum said.
The September downpour triggered major landslides in eastern parts of Hong Kong such as Shau Kei Wan and Shek O.
Massive boulders and debris blocked off Yiu Hing Road in Shau Kei Wan and Shek O’s only access road was left unusable.
“The emergency maintenance works at Yiu Hing Road will hopefully be done by the end of next month,” Shum said.
Debris, including a boulder the size of a double-decker bus, equivalent to the volume of an Olympic pool swimming pool, crashed onto Yiu Hing Road, which leads to Sai Wan Ho, and caused huge disruption to local people’s lives.
Shek O residents were cut off from the city after heavy rain forced the closure of the only road in and out.
The downpour also triggered Hong Kong’s longest-ever black rainstorm warning.
The weather left drivers stranded in their cars and some shopping centres flooded.
The increased cost of carrying out the drainage work in some areas will be discussed by lawmakers on Tuesday.
The improvement work includes projects in Mong Kok, Wong Tai Sin, Kwun Tong, Kowloon City, Eastern district, Sha Tin, Sai Kung and Tai Po.
“The latest estimated price tag has included inflation and other costs,” a source told The Post.
The work is expected to start in the third quarter and will be completed in stages from the first quarter of 2028 to the third quarter of 2030.