Flinders Ports Dredging Application Approved

Planning Minister Stephan Knoll announced today that the South Australian Government is giving Flinders Ports the green light to widen the Outer Harbor shipping channel to increase the region’s export capacity and grow the economy.

In July 2017 Flinders Ports lodged a development application with the State Commission Assessment Panel (SCAP) to widen the existing Outer Harbor shipping channel to accommodate larger vessels.

The project involves dredging 1.55 million m³ of material along 7 km of channel and disposing dredge spoil over a 7 km by 5 km area into deep water (>30 m) in the middle of Gulf St Vincent, approximately 30 km from Outer Harbor.

According to Flinders Ports, the volume is approximately half the amount of material that was removed from Outer Harbor in the 2005 Channel Deepening project, not double as suggested in recent media coverage.

The Minister for Planning approved the channel dredging development application on 28 May 2018 subject to 8 conditions, many of which had been advised by the EPA.

As stated in the Minister for Planning’s decision notification, prior to commencement of dredging works, Flinders Ports will be required to prepare an environmental monitoring program (EMP) to the reasonable satisfaction of the EPA which:

  • is designed to measure the zones of seagrass impact predicted in the hydrodynamic modelling documented in the technical memorandum prepared by BMT WBM on 23 October 2017;
  • incorporates, as a minimum, the monitoring of seagrass conditions using a ‘before after control impact’ (BACI) design measuring appropriate seagrass health metrics at an appropriate spatial and temporal frequency.

In addition, the Minister’s approval conditions require Flinders Ports to prepare a dredge management plan (DMP) to the reasonable satisfaction of the EPA prior to commencement of the dredging works.

The DMP needs to be designed to provide for real-time adaptive management of dredge plumes (incorporating ‘alarm’ and ‘hold’ triggers and management actions if triggers are exceeded,” the notification said.

The DMP also needs to include a number of other specific technical details, including:

  • the need for real-time access to telemetered water quality data at monitoring sites;
  • the need for appropriate management of biosecurity risks, as endorsed by PIRSA.

Flinders Ports is planing to begin dredging works in Autumn 2018. This will avoid dredging in summer when seagrass is more susceptible to damage from turbidity impacts.