PORT WORKS DESIGN MANUAL PART 5 Guide to Design of ...

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3. DESIGN CONSIDERATIONS
3.1 General
The design principles of a beach nourishment scheme are similar to those of a general marine
works project. There are, however, some design aspects or steps that are specific to beach
project, and they are highlighted as follows :
• Assessment of the wave, current and bathymetry conditions at the beach to
ensure that the beach is safe and suitable for swimming.
• Agreement of the beach size with the client.
• Determination of the sand quality that satisfies the requirements of beach
stability, beach users’ comfort and aesthetics.
• Design of sand quantity, construction beach profile, equilibrium beach profile
and equilibrium plan shape of the beach; the beach area under the equilibrium
profile and plan shape should satisfy the beach area specified by the client.
• Design of beach protection structures or sand retaining structures necessary to
maintain the stability of the beach.
• Investigation of the acceptability of the hydrodynamic conditions at and around
the beach and stability of adjacent shoreline due to the construction of the
beach protection structures or sand retaining structures.
• Determination of post-construction monitoring measures for evaluating the
effectiveness of beach nourishment.
• Study of the environmental acceptability of the project by carrying out
environmental impact study and determine any mitigation measures required.
• Assessment of drainage impact and determination of drainage scheme.
• Design of beach facilities and landscaping features as required by the client.
3.2 Hydrodynamic Conditions
Beach nourishment can be applied to create a new beach or to widen an existing one to
provide more areas for recreation. As a pre-requisite for such purpose, it is necessary to
examine whether the wave and current conditions are suitable for leisure and swimming
activities, in consultation with the client, beach management authority and relevant
government departments. Mathematical modelling (see Section 4.5) can assist in
quantifying the wave and current conditions in the nearshore and swimming areas.