Cockburn Cement’s marine operations are taking place as approved under a State Agreement and Ministerial Statement that allows the company to operate only in specific areas of Owen Anchorage. The activities are monitored and regulated by the Department of Water and Environmental Regulation and subject to annual reporting audit and review. Shellsand is being extracted to make lime, which is an essential ingredient in gold and aluminium processing, which is critically important to the WA economy.
The shoreline at Cottesloe is assessed and monitored by independent experts commissioned by the Town of Cottesloe. A number of reports are publicly available in which there have been no findings linking Cottesloe coastal changes to Cockburn Cement’s marine operations.
The advice given to Cockburn Cement by independent marine scientists and specialist consultants is that there is negligible ability for sediment movement from Cottesloe or other beaches north of Fremantle to Owen Anchorage.
The items highlighted on LiDAR images by Mr Schwann are showing shellsand slopes not scouring. The figure on the right, referenced as a before figure by Mr Schwann, is actually multibeam bathymetry from December 2018. The image on the left is from 2017. The difference in colours between the two figures relates to settings and the shading used in the LiDAR images.
The science regarding the separate and distinct sediment cells that control the movement of sand along the Perth coastline is well established. Information can be found in www.transport.wa.gov.au/mediaFiles/marine/MAC_R_CoastalSedimentCellsReport.pdf
Leading scientific advice and the Government document above both inform Cockburn Cement that it is extremely unlikely that sediment could move from Cottesloe Beach to Owen Anchorage.
Cockburn Cement encourages media to speak to marine scientists about this issue and can suggest:
Bruce Hegge, Adjunct Associate Professor, University of Western Australia and other roles
Cockburn Cement believes that the evidence on this issue from scientists and WA Government agencies should be enough to satisfy Mr Schwann that his theory on sand movement is incorrect.
We also draw your attention to the following recent media mentions on coastal erosion:
On the basis of existing scientific knowledge regarding sediment movement, Cockburn Cement questions the merits of the sediment sampling as it has been proposed. However, Cockburn Cement has commenced the process of consulting with scientists and regulators to determine their view of the scientific value of sediment sampling, sediment signatures, locations and timeframes.
For further information:
Luba Alexander - Group Corporate Affairs Adviser
Phone: 0418 535 636