The prevention of flooding is a major consideration for Hong Kong Engineers. The combination of tropical climate and creeping urbanisation in the New Territories creates increasing run-off problems, with downstream impact on heavily populated Kowloon.

Solutions can themselves however cause further problems as in this case, the construction of large drainage channels was at the expense of natural fauna and flora.

With advent on Environment Impact Assessment, a new approach was sought for channel design, that would provide the hydraulic capability, yet would significantly maintain the natural environment.

Such a system was available in GRASSCRETE, with a proven engineering pedigree, enabling a paving layer to be incorporated, that catered for a flow rate of over 8 metres per second, as well as withstanding the load of 30 tonne maintenance vehicles. This provided the ideal solution to satisfy both Environmentalists and Engineer and has subsequently become a benchmark design standard for drainage channels in Hong Kong.