Lower Thames Crossing supplementary consultation - Building the Lower Thames Crossing

To set out how we would manage construction of the project, we will develop a Code of Construction Practice (CoCP), in conjunction with statutory consultees and local authorities. This will include provisions aimed at minimising disruption to communities, mitigating impacts on the wider environment, and our approach to managing construction traffic.

The provisions of the CoCP will be based on the findings of the Environmental Impact Assessment, which will be documented in our Environmental Statement (ES). Both the CoCP and ES will be submitted as part of our DCO application.

If the project is approved and progresses to construction, the contractors we appoint will need to prepare and submit for approval their own Construction Environmental Management Plans (CEMPs). These will ensure the contractors’ work is delivered in line with the CoCP.

During construction, we will give affected residents, businesses and road users advance notice of planned works and provide regular updates on project progress. We will also keep disruption to a minimum on public rights of way used by walkers, cyclists and horse riders. We will do this by limiting full route closures and providing alternative routes. Wherever a right of way is affected, we will provide a nearby alternative.

Wherever possible we will protect – and look for opportunities to enhance – the local environment and improve biodiversity.

For a summary of the environmental impacts of building the Lower Thames Crossing, please see section 6 and our Environmental Impacts Update document.

To maximise the amount of daylight hours during construction, we are increasing our assumed core working hours from those presented during statutory consultation. We are planning to carry out most of the work between 7am and 7pm on weekdays (excluding bank holidays), and between 7am and 4pm on Saturdays. During the summer, to take advantage of the extended daylight hours and good weather conditions, we would undertake earthworks between 7am and 10pm. Our crews may work for up to an hour before and after to prepare and close the site.

From time to time we may have to carry out maintenance work on Sundays. We will liaise closely with highways teams from the local authorities in each affected area to identify the best working times for each site, so these may vary.

As with any project of this scale, some work would have to take place at night and on weekends. For example, where possible we would work on existing roads overnight to reduce disruption to drivers during the day.

Operation of the tunnel boring machines and associated activities for tunnel construction will take place 24-hours-a-day throughout. This would be confined to the tunnel entrances and within the tunnel, and we would put in place noise and light mitigation.

During construction we would aim to keep road closures to a minimum.

The local ground conditions mean we expect a number of ground treatment measures would be required as part of the Lower Thames Crossing tunnel works. These will strengthen specific areas of the ground or help control groundwater flows.

To treat the ground beneath the Thames Estuary and Marshes Ramsar site and Special Protection Area, we are proposing to build a ground preparation tunnel that is 5.8 metres in diameter (see diagram below). It would be located above and in between the northbound and southbound tunnels. This is subject to the contractor’s proposals.

This construction activity would take place south of the river. It would start from a shaft located south of Lower Higham Road, and travel to a shaft located north of the North Kent Railway Line. Once the works are completed, both the shafts and ground preparation tunnel would be backfilled, and the ground reinstated to its original condition. The potential environmental effects of the new tunnel have been noted in our Environmental Impacts Update.

The new road would connect the M2/A2 in Kent with the M25 south of junction 29 in Essex, crossing the A13 north of Chadwell St Mary. To connect the existing roads, as well as the A1089, we would construct new junctions and would have to carry out some work on these roads as well.

To facilitate the construction of the Lower Thames Crossing, where required, we would modify some of the existing side roads and infrastructure along the route.

How we would use other public roads

During construction, we would aim to keep road closures to a minimum. Where roads are affected by closures and diversions, temporary traffic lights or lane restrictions, we would ensure road users know in advance, so they can plan their journeys accordingly. Later in this chapter, we have outlined the routes our heavy goods vehicles (HGVs) are likely to take to transport material to and from our construction sites. Below we have detailed the average number of HGV journeys per month for each of our five construction areas, with each HGV journey comprising one trip to the site and another away from it.

Following engagement with local highway authorities and our ongoing assessments, we have amended the routes that construction traffic would use to travel to the sites. We have aimed to identify those that are most practicable and that minimise the impact on local roads and communities. Where there are no roads to the construction site, we would build temporary access roads that connect to the existing network.

We also have more information on how we can use and reuse material on our construction sites more efficiently, which will reduce the need for material deliveries and vehicle movements. Where material has to be transported from elsewhere, we better understand the capabilities of the local supply chain and expect most of this to be supplied from nearby locations. We are also continuing to explore opportunities for alternative modes of transport, such as river barges, to transport materials and waste to and from our construction sites.

(Click on the lettered icons in the image below to view the information.)

We have provided revised figures for the potential number of HGV movements in the table below, with a brief description of why this information has changed on the following pages.

Area A: We have been able to significantly cut the number of potential HGV journeys by assessing how material can be reused on our construction site to create embankments and landscaping that would help mitigate the impacts of the road.

Area B South: Moving the tunnel entrance further south has enabled us to reduce the number of HGV journeys. The maps on the following pages show the routes that construction vehicles are likely to use. The map for Areas A and B South shows a construction area over the tunnel route; no part of this is an above ground structure and would not impact on the sensitive ecological area between the southern tunnel entrance and the river.

Area B North: The potential number of HGV journeys has increased as the design of the project in this area has been updated and more information has become available. We are exploring opportunities to reduce the number by transporting material via the river.

Area C: Following further design developments in this area, we have been able to make a better assessment on how material will be reused. This has enabled us to significantly reduce the number of HGV journeys on the road network.

Area D: Following further design developments in this area, we now have a better understanding of how material is required to be used for construction. There is an increase in material needed for this construction area, which has caused a slight increase in the potential number of HGV journeys on the road network.

Construction could affect local roads through temporary closures, diversions, traffic lights and/or lane restrictions. Should the project receive consent and progress to construction, we will provide advance notice of disruption, so people can look for alternative routes or travel arrangements.

At this stage, we can provide high-level information about the planned construction on specific roads, and have outlined this in the table below. On all roads we would ensure access is maintained to properties through the use of traffic management and/or by providing diversion routes.

We previously assessed the impacts of construction on local roads and presented this during statutory consultation. The information in the table on the next page is an amended evaluation that incorporates the traffic impacts of construction. The predicted possible impacts have been classified as follows:

High: Disruption associated with construction activities, which could include a high volume of construction vehicles, and/or possible long-term closures (months to years) with diversion routes provided.

Medium: Potential for some disruption associated with construction activities, which could include increased use by construction vehicles, and/or medium-term closures (weeks to months) with diversion routes provided.

Low: Minimal disruption associated with construction activities, with a low number of construction vehicles relative to road capacity, and/or roads to remain open with potential for shortterm weekend/night-time closures or lane restrictions.

Note: During construction, where the Lower Thames Crossing crosses a local road, there may be some traffic management required, for instance traffic lights, to enable construction vehicles to cross safely.

Please note: Roads impacted by the utilities works are not included in the table below. There is however the possibility that there will also be road diversions, closures and restrictions associated with the utility works. The full extent of this information would be submitted as part of our DCO application.

At our five main sites, you would be likely to see temporary buildings and storage areas, including offices, space for equipment and materials, parking and staff welfare facilities. Our secondary sites are smaller sites, which will typically include welfare facilities, materials and equipment. Some sites would have a bespoke set-up depending on the work involved, such as the tunnel construction area at the northern and southern entrance sites, our two largest construction sites.

At the northern entrance site, we would construct a temporary substation to provide power for the tunnel boring machines. It would also power a water treatment facility, a separation facility to process the excavated material and other facilities to support tunnel construction. A new permanent substation would also be located in the service area next to the northern tunnel entrance to provide permanent power to the northern side of the tunnel.

There would be fewer facilities to support tunnel construction at the southern entrance site. As we expect to begin our tunnelling north of the river, most of the infrastructure would be located at the northern entrance site. South of the river, there would be some office and welfare facilities for our construction workers visible. Construction work associated with the earthworks operation around the tunnel entrance would also be visible. We are currently working with the utility companies to assess locations for an electricity substation within the temporary construction site in this area.

The majority of our construction sites will be reinstated and returned to their original use after construction is completed. However, some permanent above-ground infrastructure would remain at the northern and southern entrance to the tunnel.

A tunnel service building would be constructed at each entrance site to service the tunnel through its life cycle, and to ensure that it can be operated and maintained safely. These buildings would accommodate technical, operational and welfare facilities for our construction workers.

New job opportunities would be created during construction, which would boost both the local and regional economies. For our construction workers, we are currently assessing housing availability in the surrounding areas and reviewing how much temporary accommodation we would need. We expect to house some of the workforce within our construction sites and are looking to provide some of this accommodation at the northern entrance site.

The details of workforce accommodation will be agreed between Highways England and the construction contractor.