Beaches Link Tunnel virtual information session

Beaches Link Seaforth/Killarney Heights/Frenchs Forest Virtual Info Session Q and A:

How will the road changes on the Wakehurst Parkway will affect the mountain biking network on either side of the Parkway? How will the project address the changes before hand considering there are currently 10000 riders per month.

Answer: Read the following chapters:

• Chapter 8 for impacts during construction (Section 8.4.5, in particular Figure 8-18 and 8-19 show active transport impacts within the “Frenchs Forest and surrounds” area during construction, including temporary adjustments to the manly dam mountain bike track)

• Chapter 9 (Section 9.4.6, subheading “Impacts on active transport”) for description of changes to the active transport network as part of the project in the “Frenchs Forest and surrounds”

• Chapter 5 (Figures 5-7 to 5-9) visually shows what’s happening along Wakehurst Parkway due to the project, including active transport impacts.

How many trees will be removed or damaged?

Answer: Wakehurst Parkway has been assessed as ‘Area 5’ in Appendix W, Arboricultural impact assessment. It is estimated that 1,979 trees would be directly impacted in this area.

Of the 1,979 directly impacted trees, 339 are estimated to require replacement plantings, 2 are exempt species and 1,638 would be offset via the NSW Biodiversity Offset Scheme. Opportunities for the retention of trees would be further explored and confirmed during design development and construction planning. Further details can be found in Appendix W, Arboricultural impact assessment.

What measures are being taken to minimise noise during underground tunnelling?

Answer: While we will be tunnelling underground 24 hours a day, seven days a week, you may hear the noise for around one-two weeks in some locations. This is based on our tunnelling equipment moving about 25-30 metres per week. It is unlikely you will be able to hear the tunnelling equipment because it will be deep underground.

When we are tunnelling at shallower depths, or directly under your property, you may experience what is known as ground-borne noise generated by our work. Ground-borne noise is a bit different to air-borne noise in that you can sometimes feel it. Ground-borne noise is sometimes mistaken for vibration. A good example of what ground-borne noise sounds and feels like is an old refrigerator humming

The blue 'pond' structures depicted on the plan - are they water retention basins? If so, is there a reason why GPTs aren't being used? From experience working with Westconnex, and 3.5 years at the M5 East, I'm very concerned about water retention basins being used for stormwater treatment/retention.

Answer: They will serve both a stormwater retention function to slow down the flow of water either side of that ridgeline and they will be maintained during the operational phase once a road operator comes on board, if indeed that's the way the project goes. They would be maintained during the operational process.

On the extent of where our storm water line would outlet into, either Manly Dam Reserve or towards Garigal National Park, through detailed design, there is dissipation structures or structures which can slow the water down to ensure that any impacts to do with erosion downstream is eliminated or minimised. Those kind of structures are designed during the detailed design phase. We are still at reference design phase for the EIS, which is normal protocol.

Why is the design of the tunnel going south along Wakehurst Parkway so close to the existing road – I am very concerned about tunnelling affecting the fabric of the foundations of my house?

Answer: We understand there has been a lot of concern about the potential for vibration and settlement when we are tunnelling to cause damage to properties. Our objective is to ensure your safety and that your property is protected while we are building our tunnels and carrying out surface work.

We will offer a pre-construction property condition survey to properties eligible in accordance with the planning approval conditions for the project. This will provide a clear record of your property’s condition before our work starts. We strongly encourage you to take up this offer. If you have a pre-construction property condition survey completed, you will automatically be contacted when work that has the potential to impact your property is complete to confirm if you would like a post-construction property condition survey carried out.

These surveys are at no cost to you and you will be provided a copy of the report. We will establish an Independent Property Impact Assessment Panel (IPIAP) to verify property condition survey reports, resolve any property damage disputes and establish ongoing settlement monitoring requirements. Panel members will be highly qualified in the fields of structural, geotechnical and/or civil engineering and be independent of the government and project. If any damage is found to be directly related to our project, the damage will be fixed at no cost to you. If your property is potentially eligible for noise assessment, you do not need to contact us as we will be in touch with you directly before construction starts.

How do you know if your house is over the tunnel site? Especially where the tunnelling is shallower.

Answer: Please refer to the interactive map to see the tunnel alignment. you can type in your address in the toolbar

Will non-tonal reversing alarms be used for all mobile earthmoving equipment and light vehicles?

Answer: Yes they will be used.

How were the travel time savings and congestion benefits you are quoting calculated. The documents seem to rely on 2016 and earlier data? Chapter 9 indicates that Military Rd, Condamine St, Eastern Valley Way etc weren't included in the modelling area?

What was the period for the modelling of traffic volumes? Typically, similar projects worldwide see an initial drop in volumes which is quickly regained over following years.

Answer: Generally speaking, the traffic data and modelling which corresponds to the EIS, particularly the detailed information, is post 2016 information. For example, many of the detailed traffic surveys which the EIS uses as inputs are from 2018/2019. Traffic modelling and analysis undertaken has been developed and reviewed by Subject Matter Experts, and is also subject to review and approval by DPIE, amongst other external regulators.

There is a reasonably detailed overview of the process itself (traffic modelling) within Appendix F of the EIS. The traffic modelling is sort of a two stage process, there's one which I would describe as strategical and technically we call it macroscopic modelling process, which covers the entire Sydney area. The intent of that process is to look at long term trends in terms of looking from today's conditions or indeed the latest model calibrated by technicians, which in this case is 2016 and then looking how conditions are going to change into the future as a result of public transport projects and land use changes and indeed road projects like this one. And so I talk about those horizon years, I mentioned 2016 as being from a strategic modelling perspective, the latest calibrated and validated model we have. When looking at future scenarios, what we've assumed from the EIS and what we've presented in terms of outcomes of the strategic model are 2027, which is our assumed opening year for EIS purposes, and 2037, which we describe as our design year, or 10 years beyond opening.

All of those roads (Eastern Valley and other roads) are included in the strategic model I've talked about. Perhaps that comment was alluding to the next part of the process, which is what I described as micro simulation or operational modelling, and that's the very detailed vehicle by vehicle modelling we do to actually assess the impact at a very detailed, intersection by intersection, lane by lane type basis within the EIS. All of this is presented in the EIS.

There is a lot of information around how the road networks will operate with and without the project for those future years in a very detailed and operational sense as well.

Touching on the lateness of the currency of the traffic modelling, certainly the EIS has been in preparation for the last few years and so indeed some of the traffic data and modelling has indeed been undertaken as late as 2020, 2019, so the EIS is certainly not based on 2016 or earlier modelling, it is based on the latest available modelling.

I mentioned the 2016 model, for example. One of the things we do when we've got a calibrated model and validated model, so for example, in this case 2016 is, we continue to monitor traffic conditions beyond that point and the point being there of course that if we see traffic conditions changing materially, that triggers us to have to revisit the modelling and check its currency and improve it if indeed we see that being the case. We certainly haven't seen that the case.

The traffic modelling we've undertaken for the EIS has been developed and reviewed by both internal and external subject matter experts in this field. Indeed the Department of Planning will have their say in terms of looking at the currency and the accuracy and the validity of the modelling as well, so there is a lot of checks and balances undertaken to make sure that the modelling is robust and it provides a solid evidence base for the assessment.

Can you provide up to date modelling of traffic flows since COVID asap please?

Around COVID, we certainly feel that there are a lot of questions around COVID and how that relates to traffic modelling, does it trigger a revisiting. The short answer really it's too early to tell. I think we're all aware, especially the Northern Beaches are acutely aware that we are still in the midst of a COVID pandemic, we're not on the other side yet and there's a lot of things going on. We are at very much in an interim state right now. We have indeed, within Transport, seen a lot of traffic volumes obviously dip down quite early in the COVID pandemic but then rebound quite sharply, but at the same time we don't expect that to be a long term trend and just one of many reasons is that indeed public transport capacity is well down, as we all know now, not just the capacity is down but people are actually shying away from public transport for one reason or another.

There's the background narrative of having vaccines in place. In short, the effects of COVID aren't really, from any subject matter experts, agreed yet at this point, and that's regarding existing traffic volume transport conditions as well. The other side of COVID of course is how is it going to affect the future, how is it going to affect growth in terms of population, employment growth. These are key inputs, key assumptions into the modelling and the forecasting process we go through. So, there is a lot of unknowns right now and it's certainly too early to say how COVID is going to affect those things.

Just to reiterate, we've looked at the 2027 and 2037 future years and in that long term, at the moment, what we're seeing is that we don't expect there to be a significant material shift as a result of what is a relatively short term pandemic.

This slide shows a large area of bush to cleared, how will the many species in the Manly Dam reserve be protected, including endangered species? We already lose wallabies and the species to car strikes.

Answer: In terms of potential impacts to fauna, we've got a list of some of the threatened fauna species that have been identified in the vicinity of our site, so for instance, the large eared bat was recorded just on the boundary of our site back in 2019. There is potential breeding habitat identified within 100m of our subject land but there is no potential breeding habitat identified within our construction footprint itself. There is likely a viable population foraging on the subject land however there's unlikely for any breeding activity to be occurring within the area where we will ultimately be removing habitat.

Our management measures that have been developed for the project are summarised and collated in Appendix Y of the EIS and there will be activities, such as, we'll be working with ecologists to determine appropriate management measures to mitigate and manage any potential noise and vibration impacts during the construction period along the Wakehurst Parkway. Also listed is the red crowned toadlet, so it is known to occur particularly within that northern section up towards the Northern Beaches Hospital. It was identified in the vicinity of our project works. We're not expecting any undue impacts to the red crowned toadlet. There will be construction water quality management measures implemented during the construction phase and there'll be management measures then implemented during the operational phase, including the provision of water quality control basins and sweals and the like, which will potentially provide new habitat for that species.

In terms of the eastern pygmy possum, so it's obviously known to inhabit local tree hollows and rotten stumps along our project corridor. We didn't actually detect any during some of our targeted surveys but they were recorded back in 2018 in close proximity to that site, BL13, which is adjacent to the Sydney Water tanks. The types of management measures that we'lll apply to manage impacts to eastern pygmy possum would include for instance, we would avoid vegetation clearing during the breeding season where possible, so from May to July, such that will not have any unnecessary or undue impacts to the eastern pygmy possum.

The Rosenberg's Goanna, there were surveys undertaken throughout 2016 and 2017. This species has been recorded in the heat wooded area along the Wakehurst Parkway and is also known to occur within our construction footprint. This species do require quite large areas of habitat and they are obviously known to forage for road kill along the Wakehurst Parkway itself so again, the types of management measures that we'll be applying here is the undertaking of pre-clearing assessments prior to the start of our works and the establishment of fauna exclusion zones, so trying to keep fauna off of our construction work worksites where ever possible, and there would be procedures in place then if any fauna was found in the immediate vicinity or indeed on the construction footprint itself during the construction phase.

During the operational phase then, I have mentioned the fauna fencing along the extent of Wakehurst Parkway, along both sides, and also as well as replacing the existing connectivity measures, there is also the installation of new road crossings and new fauna underpasses as well to be provided as part of the project.

Any risk of flooding tunnel due to reservoir leak?

Answer: A sensitivity analysis was undertaken to identify potential for floodwater to enter the tunnel system. No tunnel flooding was predicted for Wakehurst Parkway as they could be managed through a combination of grade changes and standard barrier types. Design of the project also includes upgrades to the existing stormwater drainage to divert local catchment runoff around the proposed tunnel portals. Further details of the sensitivity analysis and studies to be carried out during further design development are set out in Section 18.6.6 of Chapter 18, Flooding.

Why does the route of the tunnel need to be so close to the existing parkway why can't it be further west closer the middle harbour so it minimises residential impact?

Answer: The Wakehurst Parkway tunnel alignment is quite a complex tunnel alignment as it heads down and joins the Balgowlah connection tunnel alignment, there is some quite tricky underground geometry to connect in where the two tunnels come together, one has to go over the top of one and one has to go under another. So, due to geometry, we've picked the most effective alignment to come through that Seaforth area at this stage. It's still reference design level. We can't tell people exactly under whose house the tunnel will be. It will all be subject to final geotech designs and the detailed design, which will happen after the EIS.

How do you know if you're eligible for a free property condition survey?

Answer: You will be contacted by the contractors ahead of construction commencing. As a general rule, properties within 50m of a tunnel or construction site will be offered a property condition survey.

What will be the final use and treatment of the worksites after construction (i.e. will they be returned to parkland, or will they be sold off for another use)?

Answer: The Northern most Wakehurst Parkway temporary site will be replanted Duffys Forest. The TfNSW land at the rear of Kirkwood, there has been no decision as to the future of this yet, whether it be revegetated or sold off. We have limited the extent of that site just south of Judith St not to go into the vegetated area but what will happen in the future will be up to TfNSW and Properties.

Have the traffic volumes re-confirmed in the post COVID world?

Answer: We have assumed modelling of 2027 when the tunnel opens. Some of the traffic data and modelling has been based on 2020 and latest modelling data. We continue to model traffic congestions beyond this point. The traffic modelling has been reviewed by subject matter experts in this field. The post-COVID data is too early to tell whether it will be a long term trend, which we don't expect it to be. The effects of COVID aren't agreed from this point and that's regarding existing traffic volumes.

What is the overall emissions and sustainability impact of the project (construction vehicle emissions, concrete, waste dumping and then ongoing operations etc) and how does that compare to a public transport alternative?

Answer: Vehicle emissions (both surface roads and tunnels) are described in section 8.2 of the Air Quality Impact Assessment (Appendix H). If you require a more detailed response, we will have to take this offline, as there is a lot of information to summarise in a presentation. If you have a more specific question, we will try to answer if possible.

What is the cost of this project?

Answer: The cost of the project will be known when construction contracts have been awarded.

The areas around the work site that are listed as national park and reserves, will they remain vegetated in order to hide the infrastructure during construction?

Answer: We have minimised our project footprint to the extent possible and we've really tried to stay within the road reservation corridor that exists along Wakehurst Parkway so certainly there would be vegetation retention along our site boundary. I talked about some of the mitigation measures in relation to tree retention earlier, but that might include, for example, if a tree is right on the site periphery, we would engage an arborist and work with that arborist then to potentially look at trimming that three rather than removing it. That's the types of mitigation measures that we could apply along the project boundary.

Is there an ability to see what the visuals will look like for the ventilation facilities with regards to materials and finishes. Can we view these before they are signed off?

Answer: This is part of the Urban Design and Landscape Plan which will be on public exhibition and open for feedback when the successful contractors come on board.

Is the ventilation outlet drawn to scale in the image to depict the actual size and give a clear idea of the visual impact?

Answer: The intent is that, although they're illustrative artists impressions, they are generated by the current design model and they are expected to be representative of what people will see, so the answer is yes. The size of that motorway facility is two levels, 8 metres plus 8 metres, 16 metres high with some architectural features might make it a touch higher and then the 25 metre high outlet.

How many concrete trucks are envisaged between the hours of 8pm to 6am?

Answer: There's generally a truck every 2 to 3 hours. This isn't one of our bigger tunnelling sites, this is one of our smaller tunnelling sites so requires less attendance by concrete, but there'll generally be a load every 2 to 3 hours coming to site.
As far as the heavy vehicle movements in and out of that site during the day, we're talking sort of 20 to 25 trucks, heavy vehicles in and about similar going out, so around 40 to 50 truck movements an hour and that's during the 7am to 6pm time slots. It's about 10 hours, so it's around anywhere between 400 and 500 in peak vehicle movements per day during that day time period, and that will involve small trucks in and out and also materials for fitting out the tunnel, so additional concrete during the day, mechanical equipment which needs to be fitted once the tunnelling excavation has got well under way., we start coming in behind and fitting out, so we've got stormwater drainage to install so those kind of materials need to get to the site and they come in by heavy vehicles. So, we talk about the number of movements and that's in total including small trucks and including delivery of materials in the heavy vehicles to enable the fit out of the excavated tunnel.

Could the tunnel be changed to a train or metro tunnel in future? Will buses be able to use the tunnel and will there be a dedicated bus lane?

Answer: The tunnel could not be changed to a train or metro tunnel in the future. However the project has been designed to link closely with opportunities for express bus routes.

Can we get pre development dilapidation reports for homes to ensure there is no repeat of the vibration issues with Westconnex?

Answer: We understand there has been concern about the potential for vibration and settlement when we are tunnelling to cause damage to properties. Our objective is to protect private property while we are building our tunnels and carrying out surface work. Transport for NSW will offer a free pre-construction property condition survey to eligible properties. This will provide a clear record of a property’s condition before work starts. If any damage is found to be directly related to our project, the damage will be addressed at no cost to the property owner. We will also establish an Independent Property Impact Assessment Panel (IPIAP) to verify property condition survey reports, resolve any property damage disputes and establish ongoing settlement monitoring requirements. Panel members will be highly qualified in the fields of structural, geotechnical and/or civil engineering and be independent of the government and project.
Most countries have committed to ban the sale of new Petrol and Diesel vehicles by 2030. So we will start to see a drop in new petrol vehicles long before, and the rise of electric vehicles. I assume this means the air is going to get cleaner and cleaner from the tunnels. Has that been considered in terms of emissions ... but equally the increased fire risk with electric vehicle fires in the tunnel.
Answer: Vehicle emission estimates have not considered a significant uptake in electric vehicles in the NSW fleet. This means that if there is indeed a significant uptake the impacts are likely to be lower than those predicted in the EIS.
Once construction starts, will a community representative be appointed to liaise with the community in case contractors change anything that was designed and agreed that may impact the community?
Answer: Any major changes to design will be subject to a design modification which will need to be publicly exhibited

Why can't we filter the ventilation stacks?
Answer: The independent NSW Chief Scientist and Engineer has released a report in relation to road tunnel air quality. The report found that emissions from well-designed road tunnels cause a negligible change to surrounding air quality, and as such, there is little to no health benefit for surrounding communities in installing filtration and air treatment systems in such tunnels. You can learn more about ventilation systems, filtration and air treatment systems by visiting or

During operation, will air and water quality be managed via limits set in an Environmental Protection Licence (EPL)?

Answer: Yes - the operation of the tunnel will be managed under limits set by an EPL. This includes air and water quality discharge limits.

Will there be a toll for this road? If so what is the expected pricing? Will NB residents get a refund like other motorways like M3/5?

Answer: There will be a toll to travel on the Beaches Link and Gore Hill Freeway Connection, as announced by the NSW Government in 2017. No decision has been made on the future tolling strategy.

Will it be possible to access the entry/exit of the tunnel on Wakehurst Parkway from Seaforth?

Answer: Refer to this factsheet about accessing the tunnels

This enormous number of trucks will surely have major impact on regular traffic on Wakehurst Parkway?

Answer: The combined activity for all Wakehurst Parkway temporary sites will increase traffic in the area by 4 per cent during peak construction. Overall, this is a small increase to current traffic volumes.

During the construction phase, what will happen with the sludge generated by the water treatment process?

Answer: Any by-product generated from the operation of the Water Treatment Plants would be collected, tested and disposed of in accordance with the relevant legislation, including the Waste Management Act.

Once the project is completed what is the noise expected from the ventilation outlet?

Answer: Generally, the outlets are quite high above the ground (~20m), so the noise from the top of the outlet would be minimal down on ground level at the residences.

Is the project registering for an ISCA rating, and if so - what IS Rating is being targeted? I'd expect at least a IS Version 2 'Gold' rating.

Answer: The project would seek to achieve an ‘Excellent’ ‘Design’ and ‘As Built’ Infrastructure Sustainability rating under version 1.2 of the Infrastructure Sustainability Council of Australia rating scheme. Further details can be found in Chapter 25, Sustainability.

Where will the construction workers park? Will Transport provide some off road dedicated parking for this so residents can keep their streets?

Answer: We are providing dedicated worker parking at most of our sites, and actively encouraging workers to avoid parking on the surrounding road network, to reduce the need for worker vehicles to park in local streets. This will include encouraging our workers to use public transport to access the temporary sites. Worker shuttle buses may also be provided where public transport availability to construction support sites is limited. However due to the nature of their work, some workers will still need to drive to and from the temporary sites to carry the tools they need to work. I encourage you to review the site maps for each site, which show the parking areas. These are on our portal under the fact sheets for each location.

How will you support local businesses during the build stage?

Answer: The temporary sites will bring in a significant number of workers into the local area who will inevitably be customers of the local cafes etc.