Our flood prevention strategy was formulated with due consideration of the typical characteristics of various drainage catchments, the performance of drainage systems then, and factors which would affect flooding risk.
Adopted Strategy
Flood Protection Standards
Adopted Strategy
Our adopted strategy is a comprehensive approach to tackle flooding risk from various fronts, from technical to management needs, and from short term to long term needs. It involves the following main features:
a. Setting up of Flood Protection Standards which are comparable to major overseas cities and appropriate for the Hong Kong situation for new drainage works and for gradual improvement on existing drainage systems;
b. Carrying out comprehensive studies to identify new drainage works and improvement on existing drainage systems;
c. Carrying out the identified new works and improvement works and to bring their capacities in line with the Flood Protection Standards as far as practicable;
d. Setting up of Drainage Authority under the Land Drainage Ordinance to be given legal power to protect major water courses in particular for those parts within private lots;
e. Addressing the drainage impacts brought by new developments; and
f. Carrying out comprehensive preventive maintenance of the stormwater drainage system to ensure their proper functioning.
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Flood Protection Standards
Flood protection standards are one of the most important elements of flood control and prevention strategy. Factors such as land use, economic growth, socio-economic needs, consequences of flooding and benefit-cost analysis of flood mitigation measures have been considered in developing the standards. The Government has formulated a set of flood protection standards for the planning and design of the public stormwater drainage systems in Hong Kong and there are different standards for different elements of the drainage systems. In summary, DSD adopts the following standards, which are comparable with developed countries overseas.
|
Types of Drainage |
Able to withstand flood events of this Return Period (Years) |
|
Urban drainage trunk systems |
200 |
|
Urban drainage branch systems |
50 |
|
Main rural catchment drainage channels |
50 |
|
Village drainage |
10 |
|
Intensively used agricultural land |
2 - 5 |
Notes:
a. The definition of flood events is based on the combination of extreme rainfall intensity and extreme sea levels.
b. Return Period of an event is the average time interval (in years) between which the event is expected to happen
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