Projects

Mount Dandenong Tourist Road landslide repair works, Sassafras

We’re delivering critical landslide repair works on Mount Dandenong Tourist Road in Sassafras between Mason Grove and Lennox Grove.

Project status:

Planned

Update - December 2024

We are completing the detailed design for the landslide repair and working with the relevant utility authorities and agencies including Melbourne Water and Parks Victoria, so that we can start construction as soon as possible.

Due to the size of the landslide and complexity of this site, the works cannot occur prior to the summer season. For the safety of all road users, reopening the road to two lanes prior to the completion of major structural retaining wall works is not possible.

What to expect

One lane will remain closed on Mount Dandenong Tourist Road between Mason Grove and Lennox Grove in Sassafras during summer. Traffic travelling in both directions will take turns to share one lane, with traffic management and speed reductions in place.

We have extra traffic controllers on weekends and public holidays to help improve the flow of vehicles during these busier periods where traffic volumes are higher.

If travelling through the area, please observe all traffic management and follow the direction of traffic controllers. Plan your journey and allow extra travel time.

Image below: Map of traffic conditions at the landslide site

Image of map showing the detour routes along Mount Dandenong Tourist Road in Sassafras

Download a larger version of the traffic conditions map at the landslide site

Support local businesses

Businesses in Sassafras and Olinda remain open and trading as usual. Please continue to support local businesses during works.

Traffic management plan – emergency road closure

Our crews continue to monitor the landslide regularly to ensure the site conditions remain safe. If our assessments indicate a risk to road users, we will take the necessary precautions to ensure everyone’s safety, which may include temporarily closing Mount Dandenong Tourist Road between Mountain Highway and Perrins Creek Road. If a road closure is necessary, detours will be via Mountain Highway or Olinda-Monbulk Road, Monbulk Road and Burwood Highway with access maintained for emergency services and for those within the road closure section to exit.

We are working closely with emergency service agencies and Yarra Ranges Shire Council to best prepare for and manage emergency and bushfire risks, and to consult on forecasted weather conditions.

For live traffic updates, we recommend visiting the VicTraffic website, or following @VicTraffic on Facebook or Twitter.

Image below: Map of traffic conditions if a road closure is required.

Download a larger version of the road closure map

What’s next

Construction is expected to start in March 2025 and be completed in mid-2025, weather permitting. Relocation of existing utilities as well as significant structural and drainage upgrade works will be required to repair the site and fully reopen the road.

We will work to minimise disruptions to the community throughout the construction program, including maintaining single lane access as per the current conditions where possible. There may be times we need to close the road to complete essential works. We will keep the community informed about any changes to the existing traffic conditions before construction works commence.

The landslide repair works will involve:

demolishing the existing rock wall
relocating and reinstating underground services
upgrading drainage network
building a 70 metre long retaining wall, with 8 metre deep supporting poles
reconstructing road pavement and shoulders
reinstating signs and line marking.

Image below: Example of major structural retaining wall works

Background

Following a severe weather event in July 2024, there was a landslide on Mount Dandenong Tourist Road between Mason Grove and Lennox Grove in Sassafras.
Our first priority was to stabilise the landslide, cap and redivert an existing gas main service, and clear as much debris from the roadside as possible to ensure the road was safe to reopen.

Once those works were completed, our geotechnical experts completed a range of detailed design investigations including geotechnical, hydrological, underground services, pavement and visual inspections to inform the detailed design.

Considering the damage caused to this section of the road, major retaining wall works are required to properly repair the landslide and safely reinstate the road to a two-lane road. The site is further complicated by multiple underground utilities, steep drop-offs, its close proximity to the Sassafras Creek and road width.