Browns Gap Road Works

Browns Gap Road Reopened

Forecast rainfall triggers closure of Browns Gap Road

 Due to the forecast rain event commencing from mid-week, Browns Gap Road will be closed from 12 midday on Wednesday 25 September until further notice. The rain event predicted to occur over a four-day period exceeds Councils Trigger Action Response Plan (TARP) measure which is in place to ensure risks to the public road users do not exceed tolerable safety limits. Council will conduct a site assessment following the forecast rain event.

Periods of heavy rainfall increase the risk of slope instability and there is higher risk to road users should this section of Browns Gap Road remain open. The area of slippage will be inspected during and after the rain has cleared.  If it is safe, the road will be reopened.

The Council recently installed geotechnical ground slip monitoring equipment on the embankments of Browns Gap Road which will also assist to inform potential rainfall related ground instability.

Ensuring the road is safe for road users is Council’s priority and further information will be provided following a geotechnical site assessment on Monday 30 September.

The Council is continuing to monitor Browns Gap Road with the area showing good stability at this point.  The Council is currently planning to undertake works to rectify damage caused by slope movements to the stormwater pipelines.   

The current traffic arrangements remain in place.

Survey works will be commencing from today on Browns Gap Road which will identify any failures in the drainage lines that may be causing the movement in the down slope embankment. These survey works may cause minor delays for motorists.

Browns Gap Road has been opened to one lane of traffic with traffic lights allowing motorist in and out of Lithgow. The road has a speed limit of 40kmh. The Council asks motorists to please adhere to the speed limit.

Browns Gap Road was affected by the heavy rains of the 6th and 7th of April, with recently installed monitoring equipment showing that there was slight movement on the lower slopes.

The planned core drilling will be proceeding soon.

Council is continuing to work towards opening 1 lane for traffic. The down slope lane will be closed for 1 kilometre to allow for the core drilling works.  Traffic devices will be set up to allow for the opening of 1 lane for general traffic.  A media release will be sent out to advise of the traffic arrangements for the open lane of traffic when the road is open.

The areas of work on the upslope side that were recently completed showed no ill effects due to the heavy rains.

Survey of drainage culverts and core drilling will commence as soon as the contractor is available.

The recently installed survey monitoring picked up further movement on the downhill slopes during the storms of the 20 April, this will help to pinpoint the areas that need stabilising.

The survey of Browns Gap is complete.   The identification of work zones 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.