What is taking place?
We will be carrying out upgrades at Tottenham Substation and to the power lines that connect into it. These works include building a new electricity pylon within to the substation, replacing an existing pylon, and connecting the upgraded power lines into the local network.
Some elements of these works are subject to approval of a Non-Material Amendment (NMA) application that we have submitted to the Planning Inspectorate. Originally, these lines were to route underground from Pymmes Brook before connecting into the substation. However, during site preparations we identified engineering constraints with this approach. Continuing with underground cables would require additional construction works outside the substation boundary, including within Lee Valley Regional Park. To minimise disruption, we are proposing to route the power lines over Tottenham Substation instead.
A Non-Material Amendment allows us to make small changes to the design of our upgrade works without changing the overall scope of the project. The consultation period for our NMA application has now concluded and we are awaiting a decision from the Planning Inspectorate.
If approved, the changes would allow the:
- replacement an existing 44-metre pylon with a 62-metre pylon.
- install a new 61-metre pylon within the substation.
- routing power lines over Pymmes Brook to the south of the substation.
Construction activity
In preparation for these works, enabling activities began once we receive approval for the NMA. These have included vegetation clearance south of the substation, improvements to the existing site entrance from Watermead Way, and construction of a temporary access road to allow construction vehicles to safely access the work area.
Subject to approval of the NMA, construction would begin with the foundations for the new pylons, followed by assembly and installation of the pylons and connection of the new overhead line infrastructure.
Works at Tottenham
Following the clean-up of land to the north of the substation, two new electricity pylons will be built and one existing pylon will be removed. Part of an existing substation will also be demolished.
The new pylons will help create a new connection between existing electricity line routes, allowing power to be transferred more efficiently across the network. As part of the works at Tottenham, National Grid will route a new section of power lines over Pymmes Brook to the south of the substation, which this new connection will link into.
In addition, National Grid will upgrade the systems used to monitor, control and protect the electricity network.
These works are permitted via our Development Consent Order (DCO) that was granted in 2014. Originally, one of our overhead lines was to route underground from Pymmes Brook before connecting into the substation. However, when preparing the site, we encountered engineering constraints that caused us to review our original approach to upgrading the lines coming into Tottenham Substation.
Therefore, we have submitted a Non-Material Amendment (NMA) planning application. You can find a link to the application here: https://national-infrastructure-consenting.planninginspectorate.gov.uk/.
A Non-Material Amendment allows us to make small changes to the design of our upgrade works without changing the overall scope of the project.
Continuing with underground cables would require construction activity outside the substation boundary, including within Lee Valley Park, which would increase disruption in this area. The original plan included:
- cables routing underneath Pymmes Brook
- two small cable bridges across Pymmes Brook
- two cable-sealing end compounds
To keep disruption to a minimum, we now plan to route the cables over Tottenham Substation instead. To facilitate this, we will need to:
- replace an existing pylon with a taller one.
- install a new pylon within the substation.
- route a section of power lines over Pymmes Brook to the south of the substation.
The proposed changes do not affect the overall scope, purpose or environmental impact of the project. This means we will continue to meet all the requirements set out in the existing planning permission. Construction management details will be agreed separately and are not part of this application.
Construction
Our construction activity will involve work on both the overhead line and in the substation. To prepare for this, enabling works will need to take place, including clearing some vegetation south of the substation, improving the existing site entrance from Watermead Way, and building a temporary access road so construction vehicles can safely reach the area where the new electricity pylons will be built.
Once we have permission to proceed with the changes, we will begin work on the pylons. This will start with building the foundations for the new electricity pylons, followed by assembling and installing the pylons
Temporary fencing shall be erected around cconstruction areas, which will be clearly marked and securely fenced off, with signs explaining the work and providing contact details for the project team.
We always try to keep local residents updated about any closures. To receive the latest news and updates, we encourage you to join our WhatsApp channel. You can find more information about how to join here.
Our timetable at Tottenham is still being developed and may change. This is because we need to fit works around planned outage windows, key equipment deliveries and activity across the wider programme. We also need to coordinate timing with other sites and construction phases so the overall scheme can be delivered safely and effectively.
Based on the current developing programme, the expected sequence of works at Tottenham is as follows:
May 2026 – NMA application submitted
Summer 2026 – NMA decision expected
September 2026 – enabling works begin
Our planned working hours are 7.30am – 6pm Monday to Friday. Some weekend work may also be needed, depending on project requirements. We will notify you of any weekend working prior to the work beginning.
All work will be carried out in line with UK Construction (Design and Management) (CDM) health and safety regulations. Alongside this, construction areas will be clearly marked and securely fenced off, with signs explaining the work and providing contact details for the project team. Security measures will also be in place at all work sites to help keep the public and workers safe.
Traffic management
At this stage we are unable to confirm our traffic management plans. We are currently preparing a detailed Construction Traffic Management Plan (CTMP) following the outcome of our NMA application, which will be submitted to Haringey Council for approval before any construction begins.
Nearby footpaths and public rights of way may be temporarily closed during our overhead line works. Where possible, we will inform local residents, the community, and other stakeholders in advance.
For more information and the latest updates on our footpath closures, please visit our dedicated traffic management page on our website here.
We always try to keep local residents updated about any closures. To receive the latest news and updates, we encourage you to join our WhatsApp channel. You can find more information about how to join here.
Environment
Most of the works will take place away from public access and is unlikely to be visible to most people. We are proposing two new pylons near Tottenham Substation: one pylon to the north, which would be 61 metres high, and another one to the south, which would be 62 metres high. We expect the visual impact to be limited, as there are already several pylons in the area, including some of a similar height.
The replacement pylon needs to be taller to keep a safe distance between the electricity lines and the building below.
Protecting local wildlife and the natural environment is an important part of the project. Surveys have found a low risk of impacts on protected species and very limited effects on Pymmes Brook, but a range of measures will still be put in place to minimise any environmental impacts during construction.
These measures include ecological checks before any vegetation is cleared, careful management of construction activities to protect wildlife, and controls to prevent soil or other materials from entering Pymmes Brook. A limited number of trees will need to be removed, but this will only take place following ecological surveys and in line with environmental requirements.
National Grid is committed to going beyond legal requirements for biodiversity. As part of this project, we are targeting a 15% biodiversity net gain, meaning we will look for opportunities to create and enhance habitats and leave the natural environment in a measurably better condition than before the works took place. Any biodiversity improvements will be secured for the long term, helping to deliver lasting benefits for local wildlife.
Safety
The safety of the public, our workforce and neighbouring communities is our number one priority. All work will be carried out safely and in accordance with UK health and safety laws for construction projects.
Security measures will be in place to help keep the site safe and secure. This includes security staff outside working hours where needed, as well as secure fencing and other site protection measures.
Fire safety is built into the design and day-to-day operation of the substation. The site will have fire prevention and emergency response arrangements in place, including specialist equipment and trained personnel.
These measures meet industry safety regulation standards and are designed to keep the site operating safely throughout construction.
Contact us
If you would like any further information or to speak to a member of the community relations team about the works, please use the contact form on our website or via the contact details below.
Email: [email protected]
Phone: 0800 538 5398