Green Power Warns Hong Kong Against Hard Engineering Approach to Flood Control
HK01 · 1 SOURCESabout 4 hours ago2 MIN
Summary
Green Power Director Dr. Cheng Muk-kei has published an article warning Hong Kong against using hard engineering approaches to combat flooding, citing the catastrophic China-Nepal border flood and debris flow disaster on August 26 as a stark reminder of the dangers posed by steep rivers carrying boulders . The article draws parallels between that disaster and Hong Kong's own vulnerability, referencing past incidents including the 2008 Tung Chung River flood, the 2010 Tai Po River incident, and the 2023 Tai Wai River flooding . Dr. Cheng advocates for a shift toward nature-based solutions that work with, rather than against, natural river systems.
Key Points
- The Tung Chung River originates from Lantau Peak at 880 meters elevation with a gradient of 1:5, far steeper than other local rivers such as the Kam Tin River and Shing Mun River which have gradients of 1:15 or less .
- On June 7, 2008, a record-breaking rainstorm dumped over 400mm of rainfall on Lantau, triggering floods that carried massive boulders through the river and washed containers 500 meters downstream .
- Lantau highlands receive an average annual rainfall of 2,400mm, exceeding Hong Kong's overall average of 2,200mm, increasing the likelihood of boulder-carrying flash floods .
- Dr. Cheng proposes six policy measures including prohibiting residential development near flood-prone rivers, relocating at-risk residents, preserving catchment vegetation, and strengthening flood modeling with sediment dynamics .
- Green Power first urged the government to develop river land-use planning policies in 2014, noting that new village houses are increasingly being built right beside streams despite ancestral wisdom dictating otherwise .
Why It Matters
As climate change intensifies short-duration extreme rainfall events, Hong Kong faces growing risks of flash floods carrying boulders and debris, as demonstrated by the 2008 Tung Chung incident . The article emphasizes that traditional flood infrastructure alone cannot withstand these forces, making comprehensive river basin planning and land-use controls essential to protect lives and property in vulnerable areas .
As climate change intensifies short-duration extreme rainfall events, Hong Kong faces growing risks of flash floods carrying boulders and debris, as demonstrated by the 2008 Tung Chung incident . The article emphasizes that traditional flood infrastructure alone cannot withstand these forces, making comprehensive river basin planning and land-use controls essential to protect lives and property in vulnerable areas .