Browns Gap Road Works

Browns gap road works

Browns Gap Road has been closed to all traffic since July 2022, due to immediate concerns of geotechnical instability (rockslide and embankment failure). This instability arose from the extended period of rainfall experienced over the course of 2021-2022. These intense storms also resulted in mine subsidence both underneath and adjacent to Browns Gap Road.

Since mid-2022, Lithgow City Council has been advocating for the urgent repair of mine subsidence next to Browns Gap Road. Repair of this mine subsidence was necessary prior to the investigation of geotechnical instability adjacent to the road, both upslope and downslope. With Subsidence NSW calling for tender related to the mine subsidence in late 2022, a works program was approved in May 2023 which then commenced in June 2023. This work is now complete, but more work is required before the road can be reopened to traffic.

Work is progressing on the reopening of Brown’s Gap Road.  Council understands that the community is concerned about the time it is taking to reopen Brown’s Gap Road, which was originally closed in mid-2022.  This subsidence caused distortion in the road surface which suggested the road was at risk of collapse. There was also the risk of rocks above the road being released and hitting vehicles.

With the mine subsidence repaired, Council’s consultants have been cleared to undertake more detailed inspections and site analysis. This has now occurred.

It was Council’s intention to be able to re-open the road as a single lane in August, however, following this geotechnical assessment, it is now apparent that further works are required to safely reopen Brown’s Gap Road. Two claims for funding to undertake the works are being prepared for submission by Council under the NSW Governments Disaster Recovery Fund, as follows:

  1. An initial claim for $1 million for further geotechnical investigation and monitoring, scaling of the rockface and repainting of the road for one way use is currently being prepared. On 9 November WSP undertook a further geotechnical assessment of the slope to progress this claim. This is an interim package of work which aims to reopen the road to a single lane of traffic.
  2. A subsequent claim for $5 million which seeks approval for a more comprehensive package of work. Ultimately, this package will result in the reinstatement of Browns Gap Road to its pre-disaster function.

On 1 July, changes to the assessment requirements for Disaster Recovery Funding occurred which requires that physical work cannot commence until approval is received from the NSW State Government. This application process is challenging, requiring that every dollar requested of Government is substantiated by evidence of disaster impact and a detailed project scope.

One of the key challenges is to ensure that the road is safe for the heavy equipment required to enable the removal of sections of rock from up-slope.  The recent report from WSP not only identifies future repairs and requirements for slope monitoring of Browns Gap Road, but also confirms the suitability of the road for the heavy equipment required to undertake the necessary scaling works to remove loose rocks and reduce the risk of rock falls to motorists and ongoing damage to the road.

Lithgow City Council understands the frustration of motorists who normally would use Browns Gap Road. It took a long time for the collapsed mine workings to be repaired and yet the road still hasn’t opened. We made a guarantee to re-open with single lane access in August and it didn’t happen.  The delays, while we await funding approval are not only frustrating for motorists, but Council also.

Moving forward, project updates will be provided on a weekly basis using the table below. Please call Council on 02 6354 9999 for further information.

Project Update 04 April 2024

The survey of Browns Gap is complete.   The identification of workzones has commenced and this will complement the traffic management plan that is being developed.

The options for traffic flow on Browns Gap Road will be determined to allow for stabilisation works to be undertaken whilst traffic moves along the road.

Project update 21 March 2024

While stage 1 works are now complete, survey works have commenced this week in preparation for stage 2, with survey staff being on site to map out areas of work and to see what subsurface movements have occurred over the last 3-6 months on the downward slope of the road.

The result of these surveys will determine the amount of work and type of remediation that may be necessary as the project moves forward.

A traffic management plan is still being developed with options being explored for the safest way of opening the road up to public traffic while stage 2 works are occurring. At this point in time the road will remain closed until further notice.

Project update 15 March 2024

 

The Council is pleased to announce that the stage 1 works on Browns Gap Road have been completed

The next steps are to install ground stability monitoring stations along the down slope of the road, assess the results provided by this equipment, and develop a traffic management plan to partially re-open the road for traffic.

Project update 28 February 2024

The stage 1 works on Browns Gap Road are nearing completion. As the site is cleaned up, a safety assessment will be conducted to determine the suitability of the road for traffic. This assessment considers the upcoming stage 2 works and will verify that the outcomes of the stage 1 works have been met before the commencement of stage 2 works.

The focus of stage 2 works will be on assessing the stability of the lower embankment of the road. This includes examining any cracks that may have opened in the embankment. Additionally, the work sites will be established based on this assessment. Core drilling will take place in the southern lane to ensure the road is built on solid ground and to identify any underlying issues that require resolution.

Once all safety assessments are complete the Council aims to open at least one lane of traffic, one way into Lithgow, subject to the outcomes of these assessments.

Project update 23 February 2024

The Council is pleased to announce that work has advanced to the upper section of Browns Gap. The current focus is on grinding the larger rocks located adjacent to the road, effectively eliminating the risk of these rocks falling onto the road. This process is designed to minimise the impact of vibrations on the surrounding road and any potential loose matter.

Once this work is completed attention will be shifted to approximately 300 metres down Browns Gap Road which will involve constructing protective measures along the edge of the road to guard against any future rockfalls.

Upon completion of the works on this upper section of Gap Road, we will conduct an assessment of the upper slope to ensure that the rocks posing the greatest risk of falling have been either removed or stabilised to the best of our ability. Following this, we will evaluate the ground cracking on the lower side of the road to determine the necessary works for ensuring long-term stability.

Thank you for your patience and understanding as we continue to enhance the safety and stability of Browns Gap Road.

Project update 13 February 2024

The works on Browns Gap is continuing. Debris from the slope has been cleared, and the open drains have been thoroughly cleaned. Commencing this week, we are focusing on removing larger rocks further up the road using an excavator and rock grinder. These efforts will continue until all hazardous rocks have been extracted and the area is deemed safe. However, the duration of this stage remains uncertain, as once the rocks are removed, we may encounter underlying issues that require resolution.

We kindly remind residents that the road is currently closed and will be entirely obstructed by machinery during these essential works.

Project update 15 January 2024

The first stage of remediation works on Browns Gap Road is due to start on Monday the 22nd January, weather dependent. A site meeting will be held on Wednesday 17th January to finalise any details. The works are expecting to take 3 to 4 weeks (weather dependent) to scale several sections of loose road, remove affected vegetation and install safety measures. Once works have been completed, the site will be further assessed by expert geotechnical engineering consultants to ensure the safety of the road for travel and consider any further works that need to occur prior to reopening Browns Gap Road to a single lane of traffic Henry’s Plant and Equipment Hire have been assigned the work to be completed, with geotechnical technicians also on site as the works are conducted.

Once this stage of works are complete, planning will commence on Stage 2 works, being the complex remediation of downslope failures.

Project update 13 December 2023

Approval has been received from the NSW Government for a first phase of work to reopen Browns Gap Road to a single lane of traffic under a contraflow arrangement (traffic lights). This work includes rock scaling and removals alongside road carriageway modifications. This is complex work requiring expert geotechnical support and skilled contractor involvement. A local contractor is preparing to commence work mid-January, weather and staff availability permitting.

Project update 5 December 2023

Council followed up with Transport for NSW as to the status of the application. While the approval was to be received last week, this did not occur. Council continues to press for the results of Transport’s assessment.

Project update 27 November 2023

The submission to Transport for NSW for the Browns Gap Road project was made Friday 24 November. Follow-up with Transport for NSW was immediately made, seeking their urgent response to this request for funding approval. Receipt of the application was received today (27/11/23) with written confirmation that feedback will be provided within the week. Local quotes have also been sought. Early indications of contractor availability suggest that works may be able to commence mid-January, pending approval by Transport for NSW.

Project update 20 November 2023

Staff meeting with potential local contractor scheduled today to estimate the cost of scaling. Estimates at this time are approximately $500,000, excl. contingency. Final quote to be received today (20/11/23). Final quotes received from Council’s consulting engineers (WSP) detailing site supervision and management costs. Submission of work package (approx. $1.5 million) to Transport for NSW for their consideration and approval by end of week.

Project update 13 November 2023

Since the closure of Brown’s Gap Road, the following works have been undertaken:

  • Mine Subsidence stabilisation works have been completed.
  • Council’s consulting engineers (WSP) have completed a geotechnical report to support the initial claim for the first package of Disaster Recovery Funding.

Over the past two weeks, Council has engaged the services of a dedicated Project Manager to press forward on the Browns Gap Road project. This Project Manager and Council’s Disaster Recovery Coordinator are treating this application for funding as their highest priority. It is expected that this application for the initial phase of work will be submitted as quickly as possible, but no later than 24 November 2023.

Once submitted, Transport for NSW indicate that it can take between 4 – 6 weeks for an approval to be granted. Council will pursue every opportunity to reduce this timeframe. Once approval is granted, a procurement process will immediately commence to appoint a contractor to commence the installation of monitoring equipment,  rock scaling and line marking realignment.  As it is dependent on specialist contractor availability, a timeframe for this work will be provided as the procurement process concludes.