The Government’s planned Westport container port

The draft design image on the Westport website shows the plans for the new container port in Kwinana, which includes a 10km-long, 18-metre-deep shipping channel through the heart of the Sound. The scale of dredging operation required for the channel is a cause for significant concern for many in the community.

In November 2023, the Government announced its final design and location of the port on land adjacent to Anketell Road in Kwinana.

This followed the WA Labor Government’s allocation of $400 million in the 2020/21 budget for strategic land acquisition and upgrades to Thomas and Anketell Roads in Kwinana as part of this new port – dredging costs and marine environmental impacts were estimated to be lower than most other options. When the port design was announced in November 2023, the port design also included a 2km-long breakwater.

Plans for the proposed new container port and shipping channel associated with Westport will involve dredging on a scale not previously seen in Western Australia.

Publicly available information indicates the project will require a new shipping channel around 20 kilometres long and up to 18.5 metres deep, extending from offshore of Cottesloe into Cockburn Sound. Creating this channel could involve the removal of up to 35 million cubic metres of seabed material.

While further technical detail is expected as planning progresses, limited information is currently available about how dredging will be undertaken, how sediment plumes will be managed, and how potential impacts will be monitored and addressed. This uncertainty is a key concern for many of us in the community.

The proposal will be subject to environmental assessment by the Environmental Protection Authority, including a Public Environmental Review expected next year. This process will play an important role in examining risks, mitigation measures and long-term outcomes. If approvals are granted, dredging could begin as early as 2028.

Large-scale dredging is known to increase water turbidity and reduce light penetration, with potential flow-on effects for nearby habitats. In Cockburn Sound, these include seagrass meadows that support species such as snapper, blue swimmer crabs, whiting, herring and squid, and play a broader role in maintaining ecosystem health.

The sheer scale of dredging and the plume it will create is one of the most important aspects to get right. International experience shows that recovery from major dredging activities can take many years, highlighting the importance of careful planning, transparency and long-term monitoring.

The need to manage dredging impacts carefully has also been acknowledged by the project proponents. Westport Managing Director Patrick Seares recently told the ABC that protecting the Sound is a central responsibility of the project.

This shared recognition underlines the importance of strong safeguards, clear information and meaningful community involvement as decisions are considered. And rest assured, we will be holding Westport to account on its commitment to ensuring it leaves the Sound in a better condition after the development of the new port and shipping channel.

Save Cockburn Sound supports constructive, evidence-based discussion about the future of the Sound. As the project moves through formal assessment, the community will be seeking clear explanations of potential impacts, how risks will be managed, and how the environmental, social and fishing values of Cockburn Sound will be protected.

A $13.5 million science program was set up by the Government to address a range of environmental issues arising from the proposed port development. The program involved more than 150 scientists working across 30 projects, looking at ecosystem modelling, water and sediment quality, fisheries and aquatic resources, hydrodynamic modelling, social values, noise and impacts on apex predators and iconic species.

Westport says information collected through the science program will inform its mitigation strategy and environmental impact assessment.

You can read about the science program and the results on Westport’s website here.

Quite a few things need to happen before works can begin on the port with dredging due to commence in 2027 (if approval is given by the WA Minister for the Environmwent) – one of the key things being the Public Environmental Review in 2026 when we and the wider community will have our opportunity to provide our views on the impact of Westport on the Sound.

Save Cockburn Sound will have much more to say about how we can make sure we all get our voices heard loud and clear on this nearer the time of the PER.