We restarted our trenchless installation under the River Thames on Monday 6 February. We will be restarting the open cut installation from April.

Our works in Chertsey Meads consist of open cut installation through the SANG, and two trenchless crossings into the area.

Works have been paused due to the high water table, and additional approvals needed for the River Thames crossing. The majority of the SANG still remains open for visitors to enjoy.

Work to date

We have undertaken pre-installation works including:

  • Installation and removal of a temporary bridge over the River Bourne.
  • Vegetation removal in our working areas.
  • Topsoil stripping.
  • Installation of temporary foundations and construction equipment.
  • Installation of a temporary construction compound in the SANG.
  • In July 2022 we finished our trenchless crossing installation under the River Bourne.

About installation

During installation, you will see:

  • Fencing of the working areas. Fencing material has been selected to reduce the visual impact on the SANG, maintaining low visibility of the working area.
  • The delivery of equipment, vehicles, and materials into the working area.
  • Deliveries of the steel pipes. These will be brought to site in a ‘just-in-time’ delivery sequencing – this is because we want to reduce the space needed for the compound within the SANG.
  • Stringing and welding of the pipe.
  • Diverting paths away from the working area. This will include a short diversion of Public Rights of Ways.

We started open cut installation in June 2022. This work has been paused due to excessively high ground water levels. This means we have excessive water in the trench that we cannot remove quickly enough to continue to work safely.

Once we have established a suitable temporary work design, we will recommence this section of installation. We anticipate these works will recommence in April 2023 and take three months to complete. If conditions allow, we will try to start earlier.

We will not need any additional space or be removing any vegetation or trees in order to continue this work.

We will be keeping Mead Lane open by using an installation method called pipe push to install the replacement pipeline under the private road. This is part of the open cut works.

Access to Chertsey Meads will be available throughout installation.

We have placed installation notices about the work around the working area. Please take extra care when approaching any area within our order limits as there will be people, vehicles and construction activity in this area.

The car park serving the SANG will remain open throughout installation.

We started our trenchless crossing installation under the River Thames in July 2022. The first stage of this work involved installing casings to create a supported bore through the sand and layers of the ground, before entering the clay layer.

However, the clay layer under the River Thames has proven to be much deeper than anticipated from our pre-installation ground investigations (boreholes). We have an environmental commitment to drill into the clay layer below the sand and gravel layers for installation under the river. Therefore, we have needed to pause works whilst we seek additional approval from the Environment Agency to install in the clay layer below the Thames. These works have restarted and will take around four months to complete.

The trenchless crossing under the River Bourne was completed in July 2022.

We worked with the Chertsey Agricultural Show to limit impacts to the Show and along Mead Lane.

Our working areas are fully secure with locked gates and 24-hour security.

Over the winter months, our site will be secured and checked regularly when our teams are not onsite working. We also have a security team to regularly check the site outside of working hours and overnight.

Compound 5N which is located on Chertsey Meads, will be retained until all sections of construction are complete.

Reinstatement will take place directly after the main installation works, in the next available season. All reinstatement is agreed with the landowner – Runnymede Borough Council.

  • Where the topsoil has been stripped and stored, this will be reseeded after works have been completed. Or we will allow prepare the soil for natural regeneration – in areas of grassland pasture.
  • All trees will be replanted on a one for one basis.
  • We will replant with native species.
  • We will replant as close to their original location as possible.
  • All vegetation is subject to a five-year aftercare period.

The voluntary Environmental Investment Programme (EIP) comprises a range of activities along the proposed replacement pipeline route to carry out localised environmental improvements, such as enhancing local biodiversity within environmentally classified sites and/or areas of social/community importance.

We have agreed activities in Chertsey Meads that Runnymede Borough Council will undertake, as the landowner. The EIP activities total a £50,000 investment and include:

  • Fencing and cattle grids in the west of the SANG for works detailed within the Chertsey Meads Cattle Grazing Scheme. Livestock plays a key role in maintaining species rich habitats through the control of more aggressive plant species that may otherwise dominate the area. Livestock management can help prevent scrub encroachment.