What’s been done so far in Eryri, what is coming up and what will happen as the project progresses.

Autumn 2014

A section of overhead lines in the Eryri National Park that crosses the Dwyryd Estuary near Porthmadog was identified as having a significant landscape and visual impact.

Winter 2014 – Autumn 2015

National Grid and independent landscape consultants undertook further technical work and considered the detailed input from local stakeholders in Gwynedd and the National Park. This enabled the project’s Stakeholder Advisory Group to prioritise the section of transmission line as one of four to be taken forward in England and Wales in September 2015.

Spring 2015

National Grid, working with local partners, established a Stakeholder Reference Group. The following organisations regularly attend these technical meetings:

  • Cadw
  • Gwynedd Archaeological Planning Service
  • Cyngor Gwynedd
  • National Trust
  • Natural Resources Wales
  • Network Rail
  • Eryri National Park Authority

Winter 2015 – Summer 2016

National Grid undertook environmental, transport and ecology surveys in the area around the line both within and outside the National Park boundary and engaging with technical stakeholders and members of the local community.

Autumn – Winter 2016

The VIP project’s Stakeholder Advisory Group reviewed the results of the environmental and engineering surveys, the stakeholder feedback and National Grid’s preferred options. The Group recommended that the project should proceed to further development work which would inform the preparation of a planning application.

2017 – 2018

Geotechnical surveys took place throughout 2017 and 2018; the results of which helped us to develop detailed engineering designs.

In November and December 2018, we carried out a formal consultation, with three days of events in Penrhyndeudraeth and Talsarnau.

Stakeholders and members of the public in Penrhyndeudraeth and the surrounding towns and villages were invited to public consultation events to find out more about our plans. This consultation also provided an opportunity to submit formal feedback on our proposals.

2019 – 2020

We undertook a pre-application consultation, including an event in December 2019 at the Eryri National Park office in Penrhyndeudraeth, and submitted a planning application in March 2020 in respect of the tunnel head house sites at each end of the project, and associated infrastructure.

In July 2020, we received planning permission subject to the discharge of a number of conditions from both the National Park Authority and Cyngor Gwynedd. Both planning committees were unanimous in their approval of the project.


Tender event held to identify and appoint the main contractor to deliver the project with National Grid.


Hochtief UK announced as our main contractor.

Survey work, detailed project design and site establishment.

2023 – 2029

Full construction work started in February 2023, with the pylons and overhead line starting to be taken down and permanently removed in 2029.