Merriwa to Willow Tree Road (MR358)


As part of our commitment to you to provide regular updates in regards to the progress of MR358 - The Merriwa to Willow Tree road (also known as Coulson’s Creek Road) please find the following information.

Upper Hunter Shire Council undertook the construction of the Merriwa to Willow Tree Road (Coulson’s Creek Rd, also known as MR358) in December 2019.

Cracking of the pavement and downslope fill embankment appeared after completion of major earthworks in October and November 2019. Further cracking developed in February 2020.

Council engaged geotechnical engineers and after an initial site inspection on 3 March 2020, the geotechnical advice on the condition of road and associated infrastructure was to impose a 5 tonne load limit and single lane configuration. Further geotechnical investigations, fieldwork and daily, weekly and monthly monitoring has continued since then.

A Project Control Group (PCG) was formed in September 2020 with representatives from Upper Hunter Shire Council, Transport for New South Wales, Infrastructure New South Wales and Public Works Advisory. The PCG has been charged with managing the road and the related design and construction phases of the project.

In January 2021, the PCG recommended following the latest geotechnical inspections, that the road be closed to all traffic with the key criteria of cracking extending to and beyond the road centre line.

Coulsons Creek Road Summary

GHD Pty Ltd – Detailed Design

GHD completed three concept designs for review with the preferred option selected for progression to detailed design. Detailed assessments of the hydrology, hydraulic design, geological and environmental conditions provided crucial data to further inform the design process. The detailed design was completed in June 2022.

Some of the documents completed during the design process include:

  1. Project Management Plan
  2. Design Criteria Report
  3. Geotechnical Option Report
  4. Concept Designs (Option 1, Option 2 and Option 3)
  5. Concept Design Report (Option 1, Option 2 and Option 3)
  6. Concept Design – Road Safety Audit (Option 1, Option 2 and Option 3)
  7. Review of Design Speeds
  8. Safety in Design and Risk Register
  9. 50% Detailed Design
  10. 50% Design Report
  11. Review of Environmental Factors (Draft)
  12. 75% Detailed Design
  13. 75% Design Report
  14. 100% Detailed Design
  15. 100% Design Report
  16. Detailed Budget Estimate
  17. Technical Specifications
  18. All Issued For Constructions Documents (Design, Specifications and Review of Environmental Factors).


Project Control Group PCG

A PCG was formed in September 2020, which meets regularly to receive updates and provide advice and directions. The PCG selected the preferred option and have undertaken reviews at key stages throughout the design process. On completion of the detailed design a business case and project proposal was endorsed by the PCG and forwarded to both the State and Federal Governments to further the case of funding.

Early Tenderer Involvement (ETI)

As part of the design process an ETI group was formed from preregistered contactors for the construction tender. This had two main benefits, firstly allowing the interested contactors to be involved in the design process, giving them a more detailed understanding of the whole project. Secondly, reducing the tender period as the preregistered contractors are the only organisations that can tender for the project. They have also reviewed each stage of the designs and provided comments on constructability, design aspects and innovative design ideas.

Upper Hunter Shire Council

Council undertook remedial earthworks at highest risk area. These works involved the excavation of the placed materials and benching to;

·       reduce the volumes and weight of the fill material,

·       restrict the infiltration of water into any remaining placed fill,

·       provide geotechnical information for structural design components and

·       lessen the environmental impacts of the placed fill continuing to move downslope.

Construction Tender

A mandatory pre-tender meeting was held on 31 January 2023 to allow the preregistered contractors the opportunity to view the site and ensure they were fully aware of the current conditions.

The construction tender closes March 16 2023

Ongoing Issues

Illegal access to the site continues to present as a concern. If this persists during the construction phase it will lead to a longer and more costly project.


Frequently asked questions

Why did this happen? Who is responsible for this?

The Office of Local Government is currently conducting a full investigation into the incident with Council’s cooperation. At the completion of this process, the findings and supporting documentation will all be made available to the public.

So what’s different this time? Why should we trust Council now?

Council is taking all necessary steps to ensure the rectification of works on MR358 are done properly and to regain the trust of the community. We are working closely with Transport for NSW on the project, with project management assistance being provided by Public Works Advisory. Geotechnical consultants from Douglas Partners continue to work with Council and are also providing their technical expertise to GHD – the consultants undertaking the design. Representatives from these agencies form part of the Project Control Group – so all decisions, including the decision to close the road, are being made with expert scrutiny. 

How long is it going to take to reopen the road?

As we are only at the start of the design process – this is hard to quantify at this time. The project could take up to 3 years to complete. However, GHD will be looking to identify priority sections of work that may allow the road to be reopened earlier under controlled conditions. Council will also be engaging civil contractors as early as possible in order to potentially start work on these sections ahead of the full design process, which will take 6 months.

How much is it going to cost us?

As above, this is very hard to quantify at this time and will be dependent on the final design. Council will, however, continue to seek external sources of funding to assist with delivery of the project and minimise the financial impact on the Shire.

Will the repaired road be able to take B-Double vehicles?

The design brief given to GHD is for the finished road to be passable by B-Double vehicles.

With Coulson’s Creek Road closed, other roads are taking more traffic including heavy vehicles. The Merriwa to Scone road is in a terrible state – what is Council doing about it?

Council will undertake a full safety audit of the Merriwa to Scone road (MR62) in coming weeks. There are significant upgrade works planned for MR62 for this and next financial years – more than $6.5 million dollars in widening, pavement renewal and other safety improvements.

What about the other roads in the Shire? Is Council going to allocate more money to roads?

Council is listening to the feedback from the community and will be preparing the budget for next year with a specific focus on improvements to road maintenance and renewal – particularly in regards to our unsealed road network.

The impacts to affected residents is a lot more than an ‘extra 30 minutes’. This is more than just travel time – this is disconnecting people from their families, work, services. Why doesn’t Council acknowledge this?

The 30 minutes additional travel time is for travel between Scone and Willow Tree – is does not consider residents along Coulson’s Creek Road that may now need to back-track. Some residents may incur up to one and a half hours additional travel time with the closure. Council does not seek to minimise the impacts of the MR358 failure.

How will Council take into consideration the personal costs to residents when choosing the final design?

Part of the Council’s consideration of the final design will be favourably weighted to the design that allows rapid reinstatement of traffic to minimise disruption to the community. This means, a more expensive design that allows quicker opening may be favoured.