HONG KONG – The Drainage Services Department is taking proactive measures as the number of flooding and landslide incidents in Hong Kong increased between 2021 and 2023 amid extreme weather events, Secretary for Development Bernadette Linn Hon-ho said Wednesday.

Answering a query at the Legislative Council, Linn said the department confirmed 257 reported flooding cases in the last three years—90 in 2021, 17 in 2022, and 150 in 2023. 

Linn said 22 locations had more than one reported flooding case. Yuen Long district had the highest number of reported flooding incidents in the last three years at 46, followed by the North district with 37, and Sai Kung with 26

The Civil Engineering and Development Department also received 146, 76 and 601 reports of landslide incidents in 2021, 2022 and 2023, respectively.

Linn said the DSD has identified some 220 locations in the territory that are prone to flooding due to blockages from debris or leaves.

“The DSD reviewed the cause of each reported flooding case and found that the major causes of flooding were blockage at drainage inlets due to leaves, sediment or debris,” Linn said. 

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“The DSD have stepped up their clearance works to the drainage channels, and carried out pre-wet season inspection and the necessary drainage improvement measures,” she added.

Linn said 22 locations had more than one reported flooding case. Yuen Long district had the highest number of reported flooding incidents in the last three years at 46, followed by the North district with 37, and Sai Kung with 26. 

“Currently, the DSD is carrying out 11 drainage improvement works. Besides, whenever a rainstorm or typhoon is forecasted, the DSD will plan in advance and early deploy inspection teams to the locations with higher risk of flooding to inspect and clear the blocked stormwater drainage system as needed,” she said.

The DSD has also been implementing a series of follow-up measures since September last year, including around 120 minor improvement works such as improving existing drainage inlets and constructing additional roadside gullies and drainage channels, Linn added. 

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To prepare for extreme weather events, Linn said an inter-departmental drill will be held next month to simulate a super typhoon hitting Hong Kong, causing extensive property damage and severe obstruction of trunk roads. 

Hong Kong was repeatedly affected by extreme weather in September last year. On the evening of Sept 7, the Hong Kong Observatory recorded an hourly rainfall of 158.1 millimeters, the highest on record since 1884

“Each (participating department) is required to explain the contingency actions to deal with different scenarios so that all participants can better understand each other's roles and responsibilities when dealing with super typhoons, helping various departments make adequate preparation and enhance their co-ordination capabilities,” she said.

Hong Kong was repeatedly affected by extreme weather in September last year. On the evening of Sept 7, the Hong Kong Observatory recorded an hourly rainfall of 158.1 millimeters, the highest on record since 1884.

Also in September and October last year, the cumulative rainfall recorded by the Observatory reached 1,600mm, accounting for about 60 percent of the average annual rainfall.

“Despite facing the record-breaking heavy rain, the overall drainage capacity of stormwater drainage system in Hong Kong continued to function well, allowing society to return to its normal operations in the shortest time,” Linn said.