Frequently Asked Questions (FAQ's)

Q. Why is Channel Deepening needed in Port Phillip Bay ?
A. Around the world there is a trend towards the use of larger and deeper container ships which carry more cargo at less cost. As a result, Portof MelbourneCorporation (PoMC) is proposing to deepen sections of existing main shipping channels in Port Phillip Bayto cater for this trend and provide the safest and the most efficient access for these ships.

Q. What size ships will Channel Deepening cater for?
A. Currently, the maximum draught (how deep a ship sits in the water) in sections of the shipping channels is 11.6m, and 12.1m at high tide. As a result of these depths, in the 2006-07 financial year, 39% of container ships were potentially affected by channel draught limitations. In the December quarter 2007 it had risen to 44.3%. PoMC proposes to deepen parts of existing shipping channels to accommodate ships of up to 14m draught.

Q. Why is Channel Deepening important to Victoria?
A. The well-being of all Victorians is directly affected in one way or another by the Portof Melbournebecause it is our trading gateway to the world. Each day on average $90 million worth of exports leave through the port, whilst in turn, everyday goods such as food, clothing, automotive parts, furniture and electronics arrive efficiently from around the world. Having these goods delivered to ‘our doorstep’ reduces transport costs and the final price we all pay.

Q. What are the main benefits of Channel Deepening?
A. Channel Deepening will ensure Melbourne can continue to accommodate the world’s growing fleet of larger ships. This will ensure the port remains Australia’s largest container and general cargo port and one of Victoria’s most important assets. This outcome will strengthen and grow Victoria’s economy, keep our exports competitive, protect jobs, generate industry and keep imports affordable.

Q. What are the economic benefits of Channel Deepening?
A. The economic case for Channel Deepening is very strong. The direct benefits are estimated at almost $2 billion, including more than $1.1 billion in savings for Victorian and interstate exporters and importers. These savings will keep down the cost of doing business in Victoria, meaning savings will flow through to consumers. The project will create 2300 jobs during the construction period.

Q. When will the project start and how long will it take?
A. The environmental studies have been extensive and PoMC adopted a realistic timeline to ensure they were done thoroughly and correctly. It is PoMC’s expectation to start dredging on or around 1 February 2008. The dredging and associated works are expected to take between 18 and 23 months. It is a condition of the Environmental Management Plan that dredging be completed by 31 December 2009.

Q. When will dredging occur?
The dredging schedule is mindful of peak holiday seasons and ecological and environmental processes in Port Phillip Bay, and makes provisions for:

• Minimising dredging works in Spring and Summer;
• No dredging between 18 December to 31 January in the South of Port Phillip Bay – in lieu of the peak holiday season;
• Restricted dredging in Williamstown Channel between 1 December to 28 February – which is a key anchovy spawning period; and
• No dredging in Yarra and Williamstown Channels with the main dredger during Spring – a period of fish migration

Q. Where will dredging occur?
A.  Dredging works will be limited to around one per cent of the bay’s area.
The works are confined largely within existing channels in two distinct areas:

• the North of Port Phillip Bay (Yarra River, Williamstown and Port Melbourne channels) and
• the South of Port Phillip Bay (South Channel and the Entrance)

The middle of the bay (north of Hovell Pile to Fawkner Beacon) is naturally deeper and does not require dredging. The turning area at Hovell Pile and Swanson Dock will be enlarged and there will be a program of berth structural upgrades. 
There will be dredging of berth pockets at Appleton Dock, Swanson Dock, Holden Dock and Gellibrand Pier.
With the exception of three small areas at the Entrance, the turning area at Hovell Pile in South Channel East and the southern end of Port Melbourne channel, there will be no dredging outside existing shipping channels.

Q. How will dredged material be managed?
A. Two dredged material grounds will be used:

In the North of Port Phillip Bay:
Dredged material from the Port Melbourne, Williamstown and Yarra River channels and associated docks would be placed in the existing Port of Melbourne dredged material ground (DMG). This existing site covers an area about 9.36km2 (or 0.48% of the 1930km2 of the bay).

It is proposed to extend this site to the south by an area of 2.70km2 (0.14% of the bay) to accommodate the dredged material volumes and provide future capacity for material from maintenance dredging over the next 30 years.

A proportion of the sediments from the Yarra River, Williamstown and Port Melbourne channels, and berth pockets, are contaminated. After dredging, these materials will be placed in an underwater clay containment area known as a bund, at the Port of Melbourne DMG, and then capped with clean dredged sand which will seal them off from any adverse influence on water quality in the bay.

In the South of Port Phillip Bay:
Most of the material dredged from the South of the bay is proposed to be stored in the newer south east dredged material ground. This will occupy an area of about 7.68km2 (0.39% of the bay). This material may be available for future beneficial use such as beach renourishment in and around the bay. Some sediment material will be placed in the Port of Melbourne site, and sand will be used for capping.

Q. Will dredged contaminants pose a risk to the bay and to human health?
A. Portof MelbourneCorporation’s level of research into the Channel Deepening Project has involved more than two years of world-class scientific investigation. This research involved a comprehensive human health risk assessment compiled as part of the Supplementary Environment Effects Statement (SEES).

As part of this assessment, the potential risk to humans (children and adults) from swimming in turbid plume and surrounding beaches was studied, taking into account incidental ingestion of water while swimming. The assessment identified no likely health risk concerns for recreational swimmers as a result of dredging existing contaminated sediment in the north of Port Phillip Bay.

Scientifically speaking, this is primarily because the contaminated particles are tightly bound to the sediment and will not be released into the water column as a result of dredging. This was noted by the SEES independent Inquiry in October 2007. The Inquiry also noted that:

• Concentrations of contaminants in the water column will be below relevant water quality guidelines from international and local sources, including the World Health Organisation.
• As the screening criteria are considered to be protective of recreational swimmers, these concentrations were not considered to pose unacceptable risks to recreational swimmers.
• Transportation of contaminated silts to beaches would not be unique to the project and may not be any more significant than that resulting from one or more recent major storms.

Q. Can dredged material be used to construct an island in the Bay?
A. This does not form part of the Channel Deepening Project, and as such would require its own environmental study.

Q. How much will the project cost?
A. The total project cost is estimated to be $969 million.

The budget takes into account:

• all the direct costs
• environmental safeguards which are unprecedented for dredging in Australia
• comprehensive environmental bay-wide monitoring programs
• the $100 million environmental bond
• recent fuel and currency movements
• an appropriate level of contingency.

Q. Who will pay for Channel Deepening?
A. The cost of the project will be fully recoverable under a ‘user pays’ system. The Port of Melbourne will remain the most cost effective port on the eastern seaboard.

Q. What technology will be used?
A. Different technology would be used in various parts of the bay depending on the type of material to be dredged. The equipment has had to comply with extensive environmental, social and economic criteria and has been thoroughly assessed in line with world’s best practice. Each dredger will be equipped with high-tech positioning systems to accurately remove material and to transport the material under prevailing conditions.

Q. Will the project threaten jobs that rely on the bay?
A. PoMC recognises that the bay is home to a range of tourism activities relying on its natural beauty and use, and that these activities account for a significant number of jobs.
Dredging has been scheduled mindful of holiday times to cause the least possible disruption to tourism and bay users. The project’s dredging schedule will minimise any disruption to the bay to as low practical.

Q. Will dredging at the Entrance cause rock falls?
A. After the trial dredge program, PoMC undertook the most comprehensive scientific study ever of deep reef habitats at the Entrance.
Using remote control vehicle and cameras, rock debris was observed in a small area within the total habitat, in an area known as the Canyon, which occupies an area of 100-120ha and has a maximum depth range of 100m. The vast majority of the Canyon will not be physically affected by rock fall, and regrowth is expected and has been observed in the trial dredge area. (The area of the canyon habitat predicted to be affected by rock fall is around 13.5ha. There will be a gradient of effects).

A significant contribution to the rock fall was the creation of loose rock, left behind following trial dredging, which was picked up by the natural ocean conditions and moved over the edge of the canyon.

The objective of minimising rock fall has been at the forefront of investigations, however the scale of works is such that some impacts cannot be prevented totally.

To address this, dredging equipment is specially designed and work methods have been modified in line with world’s best practice to reduce the volume of loose material during construction and maximise the opportunity for regrowth. Extensive scale model testing and refinement of the dredge head was also carried out in the Netherlands. There will also be monitoring and clean up of material at the Entrance during and post the works.  A payment to DSE for cool temperate research has also been made in accordance with the consent requirements by the state for the project.

Q. How long after dredging will the water be cloudy?
A. A normal part of the dredging process will be the appearance of turbidity plume, or cloudy water.  Highly sophisticated dredging technology will keep plume to a minimum although on occasions it will be visible along parts of the shoreline, and at some beaches, but is expected to dissipate fairly quickly. During the trial dredge program, turbidity levels dropped at a faster rate than anticipated, and the water cleared normally within three days after dredging ceased. 

Q. Will the plume be visible?
A. On occasions, turbid plume in the water will be visible.

• North of the bay: Most of the plume will be contained close to the shipping channel however lower levels will be evident from beaches at Williamstown, Port Melbourne and Middle Park. The impact is expected to be temporary and small.
• South of the bay:No significant concentration levels are expected to reach the foreshore, although plume will be evident from some beaches on occasions, at Rosebud and between Mt Martha and Blairgowrie, but is expected to dissipate quickly once dredging ceases (depending on winds and tide).

Q. Will the project contribute to greenhouse emissions?
A. The Channel Deepening Project will see fewer, larger ships using the Port of Melbourne.
This will improve shipping efficiency, reduce fuel use and therefore lower greenhouse gas emissions. Future developments in vessel construction including engine design will also see more fuel efficient vessels entering the port.
Climate change was factored into the project’s hydrodynamic modelling (e.g. water movements, sea levels and currents). Calculations show no coastal infrastructure around Port Phillip Bayis expected to be vulnerable to any changes.

Q. Will blasting be used in the project?
A. The Port of Melbourne has consistently maintained that blasting is not proposed in this project. The eight-week trial dredge program conducted in 2005 showed that the Entrance to Port Phillip Bay could be deepened without using blasting.

Q. Will the public have access to dredged areas during the project?
A. For the trial dredge program, PoMC openly conducted boat tours for stakeholders, media and community groups. Obviously, any measures need to be considered within the necessary safety guidelines, which cover such things as restricted access areas around the dredging equipment.

The Port of Melbourne:

• Australia’s largest container and general cargo port
• Its trade generates tens-of-thousands of jobs
• Handles around $75 billion of trade each year, that’s $142,000 every minute
• On average, handles $90 million worth of exports a day
• Has links to over 300 markets worldwide

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