Environmental Engineering Reference
In-Depth Information
Chapter 5
Beach Renourishment for Coast Protection
Abstract
Coastal protection is one of many objectives of beach renourishment
and is considered in this chapter as a background to the debate between the tradi-
tional use of structures and alternative 'soft' or adaptive options for coastal man-
agement (and protection). A number of examples are used to illustrate some of the
principles when considering beach renourishment for coastal protection.
The traditional response to coastal erosion has been to build solid structures such
as sea walls or boulder ramparts, to protect the coastline, but it has been realised
that a renourished beach that prevents storm waves from attacking the base of a
cliff can be as effective a means of coastal protection as solid structures, providing
it persists for a sufficient period to be cost-effective.
Renourished beaches have sometimes been added in front of previously built
sea walls, or inserted between groynes, as a supplementary means of coastline pro-
tection, to make the coastline less artificial in appearance and to provide a rec-
reational resource. Addition of a renourished beach on the seaward side of a sea
wall has been seen as a way of 'softening' hard engineering at several sites on the
Netherlands coast, and at Melaka in Malaysia.
In recent years there have been several projects using renourished beaches as
an alternative to engineering works to reduce erosion and coastal flooding. In the
United Kingdom beach renourishment on the Lincolnshire coast has been intro-
duced since the early 1990s to protect land and property at risk from flooding
(Sect.
4.2.7
, p. 49). The beaches and dunes stabilised by renourishment currently
protect 35,000 ha of urban and agricultural land and over 16,000 residential, 1,700
commercial/industrial properties, 19,000 static caravans and various environmen-
tal assets, as well as coastal resorts. The renourishment is estimated to protect the
hinterland against inundation from up to a 1 in 200 year tidal flood.
At Sand Bay in Somerset beach renourishment in 1984 proved successful in
stabilising the beach and dunes to protect large areas from extensive flooding until
