Major works have begun on the $31.1 million Granite Island Causeway project, with a new structure set to be complete and open to the public by December 2021.
Decommissioning of the existing heritage-listed causeway will follow in 2022.
Supporting 43 full time equivalent jobs, the project is being delivered by the Department for Infrastructure and Transport (DIT) and head contractors McConnell Dowell Constructions.
Major works officially began on Monday, April 12 and will run Monday to Saturday between 7am and 7:00pm.
Minister for Infrastructure and Transport, Corey Wingard visited the site at the weekend and said the new causeway would reflect the cultural significance of Granite Island to Traditional Owners in the area.
"This is a much-needed upgrade to secure the connection between the mainland and the island for decades to come," Mr Wingard said.
"The new causeway will have a 100-year design life that will create an elegant local landmark that will be respectful of heritage and place.
"The causeway will also meet all relevant Disability Discrimination Act 1992 requirements as well as minimising maintenance costs over time."
Major works will include piling, welding and the installation of precast concrete decking.
A progressive system of piling and deck installation will be implemented and it is expected that piling works will take place during a two hour time slot, twice per week. Two piles will be driven in each time slot, dependent on marine activity and weather, while marine observers monitor for whale activity.
A leading crane will install piles, while a second crane will be used to install concrete decking, with a total of 82 piles and 82 precast decks to be installed.
Works at the Causeway Plaza will also include the removal and upgrade of existing paving, planters and the horse tram stop.
Member for Finniss David Basham welcomed the start of major works.
"The causeway is a popular tourist attraction servicing Granite Island, tourism attractions and local businesses," Mr Basham said.
"The old causeway had reached the end of its useful life and it's crucial for the region we have a modern and safe piece of infrastructure that will serve the local community well into the future."
Sections of the original causeway will be retained and restored at either end, and it will remain open to the public until the completion of the new structure.