Power Lines Diverted under River
5 November 2010, 16:19
UK Power Networks has tunnelled under the River Cuckmere at Seaford to replace overhead power lines with underground cables in the South Downs National Park.
Last week, specialist machinery was used to burrow a 115-metre-long tunnel under the A259 and up to three metres beneath the riverbed to carry new 11,000 volt electricity cables. A second 160-metre-long tunnel has also been drilled between a field and the Seven Sisters Country Park visitor centre car park.
The project is part of a £220,000 scheme to replace 1.4km of overhead wires with underground electricity cables between Chyngton Farm and Exceat Bridge, near Seaford, to enhance a landscape which forms part of the recently-confirmed South Downs National Park.
A specialist directional drilling company was employed to bore the two tunnels to contain ducts about 12cm wide. Once all the ducts are in the ground, along the entire route, the new cables will be pulled into place and the overhead power lines will be switched off and dismantled.
UK Power Networks has a special allowance from industry regulator Ofgem to underground power lines in protected landscapes. Between 2010 and 2015 the company has £6.6million to replace overhead lines with underground cables in Areas of Outstanding Natural Beauty (AONB) and National Parks in the South East.
Shaun Barrell, UK Power Networks’ protected areas project officer, said: “We are pleased to be starting the first stage of a project that will result in the removal of overhead power lines from this beauty spot. We are using a trenchless horizontal drilling technique to lay new cables under the River Cuckmere. It is great working with the South Downs Joint Committee again on another power line undergrounding project.”
Nat Belderson, planning officer, South Downs Joint Committee, said: “This has been a great opportunity to improve the views in a popular area within Britain’s newest national park. The lines dominate views as they stride up the valley side and over land at Chyngton Farm, where they currently interrupt views to the internationally famous Seven Sisters chalk cliffs.”
The overhead power lines that will be dismantled pass up the sides of Cuckmere Valley, across open downland and close to a local nature reserve in an area popular with tourists and walkers in the new South Downs National Park. The overhead power lines also pass through the grounds of the Golden Galleon pub by the river.
In 1997 around 380 metres of power lines were removed from the floodplain, in the Cuckmere Valley, to prevent ducks, swans and geese being injured flying into the lines. Removing the remaining lines, either side of the section which has already been undergrounded, will further help local wildlife and enhance the landscape.
This is the latest undergrounding scheme to get under way in Sussex. Similar projects have taken place at:
- Birling Gap – last year £295,000 was invested to remove around two miles of power lines and more than 40 wooden support poles.
- Friston Forest – this year a £264,000 project saw the removal of 1.4 miles of electricity lines and 26 wooden support poles between Jevington and Friston.
- Bullock Down – this year a £135,240 project resulted in the removal of 750 metres of overhead power lines, nine wooden support poles and two pole mounted transformers near Beachy Head.
- Bishopstone – this year £625,000 was invested to remove more than two and half miles of overhead power lines and 68 wooden support poles between Bishopstone, Norton and Denton, between Newhaven and Seaford.
- Adur Valley – last year £496,000 was invested to remove more than two miles of overhead network and 45 wooden support poles in the vicinity of the Saxon St Botolph’s Church, at Upper Beeding, West Sussex.
- Clapham – earlier this year just under a mile of power lines was removed from the landscape as part of a £187,000 investment.
All the projects are selected by a regional steering group of environment experts, including the South Downs Joint Committee and chaired by Natural England. UK Power Networks provides technical support and guidance and carries out the work to its electricity network.