Dredging Contractor Services for South Channel and South Wave Break Island Channel Dredging

The Gold Coast Waterways Authority (GCWA) requires a suitably experienced and resourced
contractor for the dredging of the South Channel and South Wave Break Island Channel below
Wave Break Island and beach nourishment in an approved area on the north-eastern foreshore of
Wave Break Island.
The GCWA is responsible for developing and maintaining destinations and navigation channels
throughout the waterways of the Gold Coast. This project involves dredging of the South Channel
and the South Wave Break Island Channel in the Southern Broadwater to remove identified
shoaling and to return the design depths. Spoil removed during the dredging process will be
partially used for beach nourishment at north-eastern side of Wave Break Island to replenish sand
eroded via the natural coastal process in order to provide protection to property and assets. Any
excess material will be deposited offshore from South Stradbroke Island within GCWA’s approved
deposition site.
The South Navigation Channel is a primary channel with a design depth of -4.5m LAT. Routine
survey has shown two areas of shoaling with reduced depths up to -3.5m LAT. The two areas to be
dredged are between the Seaway entrance and the South Wave Break Island Channel (Area A)
and next to the Marine Stadium (Area B). An increased insurance buffer is proposed for Area A
down to -5.9m LAT with an optional bill item to further increase this buffer to -6.5m LAT. The
insurance buffer within Area B is -300mm i.e. -4.8m LAT.
The South Wave Break Island Channel is a secondary channel, connecting the South Channel and
the Labrador Channel with a design depth of -2.5m LAT. Routine survey has shown two areas of
shoaling with reduced depths up to -1.1m LAT. The channel is to be dredged in its entirety.
Approximately 15969 cubic metres of material will be removed from the dredge areas. The dredge
locations provide the opportunity to use the dredge sand for beach nourishment at the North-
Eastern side of Wave Break Island. This area has suffered severe erosion in recent years exposing
the northern rock wall and requires urgent remedial works.