O'Shannassy Aqueduct Trail Dee Slip Bridge Project

Project status

Last updated: July 2025

This project is being delivered on Wurundjeri Country.

Repairs to Dee Slip Bridge in the Yarra Ranges National Park are about to commence, restoring pedestrian, cyclist and emergency vehicle access along the much-loved O’Shannassy Aqueduct Trail on Wurundjeri Country.

Designs to repair the bridge have now been finalised and we are in the final planning phase. These repairs will keep to the original design of the bridge and retain as much of the existing timber as possible.

Current access

The bridge remains closed to the public and barriers have been put in place to keep the community safe. The temporary bypass track should be used by the public prior to the construction period.

Project timelines

During June we undertook a tender process . After an evaluation period, the decision to award the construction contract will be made in August.

We expect construction to commence in spring 2025.

The bridge is scheduled to reopen in early 2026.

Project background

The Dee Slip Bridge is a timber trestle bridge spanning a section of the O’Shannassy Aqueduct Trail in the Yarra Ranges National Park. The bridge was constructed in 1947 after the aqueduct collapsed and the force of the water flow created a large hole in the side of the embankment. For many years the bridge was used as access to both the aqueduct and the walking trail.

The bridge was closed to vehicles in 2017 after engineers determined it to be nearing the end of its useful life.

In 2021, the bridge was damaged when a large pine tree collapsed onto it. To keep the community safe, access to the bridge has since been closed and a new temporary bypass track on the low side of the bridge has been created for public use in the interim.

Project funding

The Dee Slip Bridge project is part of the Asset Regeneration Program, a $24.76 million investment by the Victorian Government to remove unsafe infrastructure and repair or replace assets across Victorian parks.

Staying updated

Information about this project will be maintained on this webpage.

You can also subscribe for updates here.

Related information

July 2025: Community update

News July 2025: Parks Victoria to repair and reopen the O’Shannassy Aqueduct Dee Slip Bridge

FAQs

Why has the Dee Slip Bridge been closed?
A 2017 engineering assessment of the bridge determined the structure was nearing the end of its useful life. The bridge was then closed to vehicles and remained a pedestrian and cycle bridge.

Another engineering assessment was undertaken in 2020 and recommended minor maintenance and long-term closure once the asset reached the end of its lifecycle.

In 2021, a large pine tree fell and hit the bridge causing further damage. The bridge was closed until an engineer assessment was carried out in April 2021. This assessment concluded that the bridge was unsafe and should remain closed to the community.

Since then, Parks Victoria has been undertaking investigations to understand future design options for the bridge.

After engaging a team of engineers and expert consultants, Parks Victoria has settled on a final design that restores visitor and management vehicle access across the bridge and preserves its heritage values.

We ask the community to please not access the bridge while it is closed. Barriers have been put in place to keep the community safe and a temporary bypass track should be used by the public prior to the construction period. During construction, there will be no access across the bridge. Check the change of conditions on the Parks Victoria website to stay informed, and respect on-site signage as it is installed.

What works are Parks Victoria carrying out to repair the bridge?
Parks Victoria will repair and preserve the heritage of the Dee Slip Bridge by:

Replacing the existing timber deck and handrail like-for-like to restoring the heritage value of the design.
Adding steel girders to remove structural reliance on deteriorating timber log beams.
Keeping the existing timber log beams where possible for heritage value.
Replacing existing timber crossheads with steel sections where necessary.
Extending and supporting the end spans to by installing new abutments at either end of the bridge.

What work has Parks Victoria undertaken on the Dee Slip Bridge project so far?

Parks Victoria has completed a number of investigations including:

Creating a new temporary bypass track on the low side of the bridge, allowing for a safer crossing route while long-term planning for a permanent solution continues.
Engaging a team of engineers who have thoroughly inspected the bridge and put forward a design detailing the most sustainable solution to restore access across the bridge.
Engaging a team of site surveyors to record the bridge and surrounding areas. This team produced a set of survey drawings which informed the design work on the project.
Engaging a quantity surveyor to provide financial guidance on how to maximise the project budget and deliver the best outcome possible for the community.
Engaging specialist approvals consultants to visit the bridge and compile planning, heritage, and environmental data to ensure the project complies with relevant approvals.
Engaging cultural heritage specialists to provide direction on how to minimise any impacts to culturally significant heritage areas on the site.

What access is required for emergency services?
Parks Victoria has consulted Forest Fire Management Victoria to ensure that their emergency access needs are met.

What are the next steps and timelines?
The designs to repair the bridge have now been finalised.

Parks Victoria is undertaking a tender process throughout June.

After an evaluation period, the decision to award the construction contract will be made in August.

Parks Victoria expects construction to begin in spring 2025, with the bridge scheduled to reopen in early 2026.

Where is the Dee Slip Bridge on the O’Shannassy Aqueduct trail?
The Dee Slip Bridge is located along the O’Shannassy Aqueduct trail 1.1km east of Dee Road in Millgrove.

How will access along the O’Shannassy Aqueduct trail be impacted during construction?
A construction site will be established at the Dee Slip Bridge and there will be no access over the bridge or via the bypass track during the construction period. Partial closures of the O’Shannassy Aqueduct trail will be required between Dee Road (West) and Sussex Street (East).

East of Sussex Street, access along the O’Shannassy Aqueduct Trail will remain unaffected.

Check the change of conditions on the Yarra Ranges National Park page on the Parks Victoria website to stay informed, and respect on-site signage as it is installed.

Parks Victoria thanks the community for their ongoing patience throughout the project.

Will you be consulting with the community on this project?
We’ll be sharing comprehensive project updates with the community and stakeholders informed as things progress.

To stay up to date, you can subscribe here.