The objective of this report is to provide a basis for improved discussion on port related dredging in Australia and associated environmental impacts.
It focuses on dredging by ports in southern Australia (temperate ports) and complements an earlier report prepared for Ports Australia (Morton and Sprott 2014) which related to northern ports (subtropical and tropical ports).
The report highlights the importance of ports and shipping channels to the Australian economy and the critical role of dredging in port operations and growth. It provides an overview of the approval processes associated with dredging and at sea placement of dredged material and the nature of environmental monitoring programs associated with recent port related dredging projects.
The report compares monitored environmental impacts associated with recent major dredging projects at Sydney, Melbourne and Fremantle ports, along with other important regional dredging projects, with those stipulated by government through the environmental approval process.
The report finds that of the nine major capital projects reviewed, eight resulted in impacts consistent with or less than predicted. One resulted in impacts greater than predicted however recovery occurred over several years. This finding is consistent with the report relating to subtropical and tropical Australian ports (Morton and Sprott 2014).
Together, these two reports constitute the first detailed review of all major port related dredging projects undertaken in Australia since the early 1990s and highlight the:
- consistency of compliance with project approval conditions;
- rarity of unpredicted impacts or adverse effects to areas of high conservation value; and
- the high level of environmental performance of often substantial dredging projects.