New Bridgewater Bridge

The reference design for the New Bridgewater Bridge was released on Monday, 19 October 2020.

The reference design includes a new two lane bridge and a second two lane bridge built on the alignment of the existing bridge, creating two lanes in each direction. This includes the removal of the existing bridge.

The reference design shows what may be built to deliver the project’s design requirements within the budget that is available and is used to seek feedback from the community.

The reference design is not the final design for the new bridge, and it is likely it will evolve throughout the competitive design process as contractors look for the most value for money solution, while considering community feedback.

Consultation on the reference design is happening between Monday, 19 October 2020 and Friday, 13 November 2020.

The Tasmanian Government has confirmed the eight design requirements for the new bridge.

The design requirements are:

1. The project will provide a new river crossing between the Brooker Highway and Midland Highway, including connections to the Lyell Highway.
2. The new bridge will have a minimum design speed of 80km/h.
3. The new bridge will include two lanes in each direction.
4. The project will include the grade separation of the Lyell Highway Junction at Granton and Black Snake Road at Granton.
5. The new bridge will have a minimum airdraft clearance consistent with the navigable clearance under the Bowen Bridge.
6. The new bridge will include a shared path for pedestrians and cyclists.
7. The new bridge will include safety screens and barriers.
8. The new bridge will not preclude the future use of the existing rail corridor.

Key design requirements for the new Bridgewater Bridge.

A range of possible bridge designs are capable of meeting these requirements within the project budget, and two high-level concept designs were released to the community for information in July 2020.

The reference design, and all feedback received, will be given to the two contractors selected to take part in the Early Contractor Involvement process. It will be used by the contractors to develop the final design that they will submit as part of their tender.

The contractors will use their specialist knowledge, expertise and community feedback to identify solutions that improve the design and deliver the best outcome for Tasmania.

A contract will be awarded in late 2021 and a detailed design for construction will be finalised soon after that, ready for construction to start in 2022.

Geotechnical, heritage and environmental investigations to inform further development of the final bridge design started in January 2020 and are ongoing.

These investigations include analysis of the ground conditions approaching the proposed new bridge location, depth and quality of bedrock under the river, the mapping of rock faults and the properties of river sediments. This will help determine the final design for the bridge foundations.

The Department of State Growth has commissioned comprehensive environmental, Aboriginal and historic cultural heritage investigations to ensure that all values in the development zone are considered throughout the design and development phases of the project.

These investigations commenced earlier this year and are ongoing, including regular bird life surveys.

During these investigations, there will continue to be people working near the existing Bridgewater Bridge, including around the causeway and bridge, around adjacent properties and in the River Derwent.

There may be traffic management where work is taking place close to the road. Changed traffic conditions and warning signage will alert road users when works are underway.

Road users are asked to approach the area with caution, and follow the directions of traffic controllers and signage.

What is the purpose of the reference design?

The reference design shows what may be built to deliver the project’s design requirements within the budget that is available and to seek feedback from the community. The reference design, and all feedback received, will be given to the two shortlisted contractors to use to as they develop the design they will submit as part of their tender.

Is the reference design the final design for the new bridge?

No, the reference design is not the final design for the new bridge. It is likely that the designs being considered will evolve throughout the competitive design process as contractors look for the most value for money solution, while considering community feedback. The final design developed by the contractor must still fit within budget, meet the project’s design requirements and comply with planning conditions.

How will my feedback be used to determine the final design?

Comments and feedback received from the community on the reference design will be given to the contractors as they develop their own, more detailed designs. The contractors will use their specialist knowledge and expertise to identify solutions that improve the design to deliver the best outcome for Tasmania.

When will a design for the new bridge be finalised?

A Design and Construct contract will be awarded in late 2021and a detailed design for construction will be finalised soon after that, ready for construction to start in 2022.

Will I have another chance to provide feedback on the bridge design?

Feedback is most beneficial early in the design process, which is why feedback is being sought on the reference design now to inform the development of designs by the two shortlisted contractors.  However, the community will have further opportunities to provide feedback during the 2021 planning approval process.

When will construction start?

Early preparation works such as demolitions and service relocation will start prior to a contract being awarded at the end of 2021. Construction of the new bridge is due to start in 2022.

When will a new bridge be finished?

We are working to have people driving on the new bridge by the end of 2024.

Reference design (13MB PDF)

Pedestrian and cycle paths (3.2MB PDF)

Travel routes (5.5MB PDF)

The River Derwent crossing at Bridgewater has a long history, dating back to 1830 when convicts started construction on the causeway. A punt was then used to complete the crossing from the end of the causeway to the northern bank of the River until the first bridge structure was completed in 1848.

The existing lift span road and rail bridge was opened in 1946 and is the fourth bridge to be built at this location.

The existing bridge no longer meets contemporary design or loading standards and constrains productivity on the heavy vehicle network. The age of the vertical lift span makes its operation unreliable and expensive to maintain.

Building a new Bridgewater Bridge is another chapter in the evolution of the crossing at this location.