The Waitematā Harbour has reasonably strong tidal movements, which reduces the build-up of sediment in the channel.
Some siltation in the port basin comes from the run-off from stormwater outlets from surrounding city catchments. Auckland Council is working to upgrade the city stormwater system, which will help to reduce siltation and its impacts on water quality in the harbour.
Ports of Auckland carries out a programme of regular maintenance dredging around its wharves to keep berths at notified depths.
Responsible Disposal of Dredged Material
Like all ports, Ports of Auckland needs to dredge its channel and berths so ships can get in and out of port safely.
Dredgings currently are disposed of in the reclamation area at the north-east corner of Fergusson Container Terminal. The dredgings are mixed with cement to make mudcrete for the reclamation. Because the mudcreting quickly binds dredged sediment into a solid mass, there is very little impact on the harbour or the water quality. The dredged material is predominantly marine mud. Extensive monitoring has found no problems with contamination or biotoxicity. This is both cost effective and environmentally friendly. But soon our reclamation project will end and we will need a new way to dispose of dredged material.
We intend to apply to the Environmental Protection Agency (EPA) for a 35-year consent to dispose of dredged material at sea under the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act 2012 (EEZ Act).
The authorised “Cuvier Dump Site” location 27 nautical miles east of Cuvier Island (indicated on the map below).
Further information on the marine consenting process can be obtained from the EPA website.
For more information from Ports of Auckland, please contact:
+64 27 558 8076
+64 27 204 3150