The Western Australian government has unveiled its preferred design and location for a new container terminal in Kwinana, just south of the port of Fremantle.

A new terminal has been planned for several years, with modelling said to consistently show that Fremantle Port and its surrounding roads will reach capacity within the next two decades.

Fremantle, south of the state capital, Perth, imports and exports around 800,000 teu annually, but this is expected to grow to more than 3m teu over the next 50 years.

“Ensuring Western Australia has a terminal and freight network capable of supporting the projected growth in container trade is critical to the state’s economy over the next century,” said state Premier Roger Cook.

The Western Australian government said the preferred design includes a container terminal adjacent to the shoreline of the current Kwinana Bulk Terminal; a new breakwater to enhance protection of the port and docked ships; and major upgrades to key freight roads leading to and from the new terminal.

It said the design of the container terminal will allow it to cater to larger ships than the existing Fremantle terminal and incorporates redevelopment of the ageing Kwinana Bulk Terminal jetty.

Design concepts were said to have been assessed against criteria including environmental impact, long-term sustainability, efficiency of the supply chain network and port, and financial value to the state and local economies.

Planning and engagement with stakeholders on the appropriate location for non-container trade based at Fremantle Port is continuing.

The project business case, including the recommended development timings and costings, is expected to be finalised in mid-2024.

“A world-class port in Kwinana is critical for our state to remain a global economic and industrial powerhouse for decades to come, supporting thousands of local Western Australian jobs,” said Cook.

“Through this design, we can ensure Western Australia can continue to meet trade demand long into the future — while strengthening our supply chain lines.

“Only our plan will future-proof Western Australia’s container trade and economy for the next 100 years, and transform communities in Kwinana and Fremantle.”

Transport minister Rita Saffioti said the new container terminal and supporting freight network would represent one of the largest infrastructure projects ever undertaken in the state.

“The modelling over a number of years has been consistent and shows Fremantle Port and its surrounding road network will become significantly constrained within the next two decades,” she said.

“Having a port and freight network that can support the expected growth in Western Australia’s container trade is absolutely essential to the long-term health of our economy.

“Any restrictions on our capacity to meet future demand for container trade would place a significant handbrake on our economy.”