Bunbury Port Authority proposes to extend the Inner Harbour at Bunbury by dredging a strip of land to the south-east of the existing basin, to allow for two additional ship berths and associated on shore facilities. The dredged spoil would be used to complete the filling of partially filled areas, to make them suitable in accordance with current zonings for bulk storage and port related activities.
Dredging would be undertaken by a cutter suction dredge to a depth of 12.2m. Material would be cut below sea bed level by the rotating cutter head, and drawn into a large diameter suction pipe to be pumped ashore. The dredged material would be mostly sand and silt. with smaller quantities of limestone and weathered basalt. If fresh basalt is found, controlled blasting would be required to remove it.
The total volume of dredged material is estimated at some 1.8 million m3. All the dredged spoil would be pumped hydraulically to reclamation areas. These are land areas to the north-east of the Inner Harbour, bounded by Vittoria Bay on the Leschenault Estuary, Preston River, existing alumina leases and State Electricity Commission land. They were partially filled when the current Inner Harbour was dredged in the early seventies.
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