Environmental Engineering Reference
In-Depth Information
means of a renourished beach will be effective as long as that beach is maintained,
if necessary by periodic renourishment.
The beach was thus restored in the southern third of the Sandringham beach
compartment, but north of the Edward Street groyne it remained narrow, and occa-
sional storm waves began to undercut the backing bluff. In 2004 there was discus-
sion on whether this could be controlled by emplacing another protective artificial
beach, or whether a solid sea wall would be built. Critics of the sea wall proposal
pointed out that the fronting beach would be further depleted by reflection scour.
Seasonal alternations of longshore drift continued, and in the winter months sand
drifted southward to form a protective beach in front of the eroded cliffs, but in the
summer it drifted away, exposing the cliffs to renewed wave attack.
In 2008 a groyne was built opposite Southey Street at the northern limit of cliff
erosion, and sand from Sandringham Harbour was piped a kilometre southward
to renourish the beach between the new groyne and the one previously built at
Edward Street (Fig.
5.6
). This has stabilised the coast in the central part of the
Sandringham beach compartment, but the northern part now shows beach deple-
tion and incipient cliffing of the backing bluff, and it may yet be necessary to add
a further groyne and renourish this next section.
The insertion of groynes in the Sandringham beach compartment led to protests
by some local people (despite the fact that groynes had been introduced successfully
Fig. 5.6
The renourished beach between groynes at Sandringham, Port Phillip Bay, in 2010.
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