Introduction
National Grid gained development consent on 19 January 2016 from the Secretary of State for Energy and Climate Change (now the Department for Business, Energy and Industrial Strategy) to build a new high voltage electricity transmission between Bridgwater to Seabank in Avonmouth. This was to connect Hinkley Point C to the National Grid. Full details of the Development Consent Order are available on the Planning Inspectorate’s website.
The route goes through these council areas: Bristol City Council, North Somerset Council, Somerset Council and South Gloucestershire Council.
The project comprises the erection of 48.5 km of new 400,000 volt overhead lines. 8.5 km of cabling will be laid underground passing under the River Axe and continuing through the Mendips. Cable Sealing Ends, similar in appearance to a small sub-station, will be constructed at the point where overhead lines join the underground cables. To make way for the new connection, and to minimise the impact on the local landscape, 65km of the existing Western Power Distribution overhead 135,000 volt lines will be removed.
Associated works include the formation of haul roads, site compounds and new access points (bellmouths) off the public highway for construction traffic. New planting will screen certain parts of the development and additional planting will be undertaken within a 3km zone of the route to reduce the overall impact of the new connection and enhance local landscape and biodiversity. This planting is known as the ‘Off-Site Planting and Mitigation Scheme’ and must be completed as part of a legal agreement between National Grid and the Local Authorities.
The scheme will be completed in 14 stages, with the removal of the existing overhead lines and the reinstatement of the haul roads, site compounds and vehicular access points being the later stages. Sedgemoor is involved in 3 of the stages, detailed below:
Stage 2: 400kV underground cables through the Mendips
Stage 2.1 will commence in the Spring of 2019 with construction work at the A38 at Tarnock followed by cable laying which will progress northwards from Tarnock to the A368 near Sandford, North Somerset. This stage will also include landscaping and advance planting works at the Cable Sealing End compound next to Loxton.
Stage 2.2 will comprise of final landscaping and replacement planting and will take place during the third quarter of 2022 and completed at the start of 2024.
Stage 7: 400kV overhead line south and 'F' route south
- Stage 7.1 will commence in early 2020 and will be completed at the end of 2022. The stage consists of the installation and removal or temporary works, installation of permanent 400 kV overhead line pylons and conductors and the removal of existing associated 132kV overhead line and conductors.
- Stage 7.2 will commence towards the end of 2022 and will be completed towards the end of 2024. The stage will consist of the installation and removal of temporary works, installation of permanent 400 kV overhead line pylons and conductors, and the removal of existing associated 132kV overhead line and conductors.
- Stage 7.3 will comprise of landscaping and replacement planting and will commence during 2022 and will be completed in 2025.
Stage 13: Works at Bridgwater Tee
Works will commence towards the end of 2022 and be completed in 2025. The works will consist of the installation and removal of temporary works (bellmouths, haul roads and working platforms), the permanent installation of the 400kV underground cable and Cable Sealing End compound, low overhead line pylons and associated conductors, and the removal of existing 400kV overhead line conductors.
The Development Consent Order requires National Grid to seek approval from Somerset Council for specific details prior to the start of each of the 3 construction stages of the project. These are called ‘requirements’ and are similar to planning conditions. Submissions located in Sedgemoor will be made available via the Council’s Planning Online website.
The Council will discharge the ‘requirements’ and will need to consult a number of statutory consultees in the process.
In advance of each stage of the project commencing, National Grid will notify District Councillors, Parish Councils and residents, businesses and landowners within a certain distance of the construction site.
For the latest information regarding the project, the National Grid’s website.
Background information
The current Planning Performance Agreement (PPA) and Development Consent Obligations for the project are available to view below. The PPA is a formal agreement which provides a framework to enable the Councils to respond and manage the additional demand for resources which result from the project.
