Abstract:
This report addresses environmental concerns of the proposed change to shore-protection
measures for Villingilli western coast. The initial proposal had a rock boulder revetment at the
western side of the island. However, due to distance between reef edge and proposed
revetment, a section of this revetment could not be implemented. The proponent therefore
proposes this section of revetment to be constructed using concrete T- Unit Blocks. The total
length of proposed revetment is 255m; currently 200m of the revetment is constructed using
rock boulders; 55m of the remaining revetment is proposed to be constructed using T-Blocks.
As the only proposed change is material used for revetment, there is little change to impacts
predicted during the initial EIA process. The most significant of which is change to local
wave and current regime due to relatively less energy absorption by the T- Unit blocks and
change to wave dispersion mechanism. Compared to initially proposed rock boulders, T-Unit
blocks reflect waves more and may therefore induce turbulence; however, construction of
rockboulder revetments require more space for base. The proposed location for revetment
construction is very close to reef edge and a section of proposed revetment could not be
implemented due to absence of enough space for rockboulder revetment base.
As identified in the EIA process, during construction of the revetment, there will be some
degree of sedimentation in the area. However, due to strong currents and small amount of
excavation required, sedimentation is not expected to cause significant environmental loss.
Due to limited negative impacts predicted for the proposed change in revetment, no major
mitigation measures were identified. However, it is strongly recommended to adhere to
mitigation measures proposed in initial EIA.
