Onshore elements

The energy generated offshore would need to be connected to the National Grid.  The onshore elements are as follows:

• The high voltage cables from the windfarm's offshore substations would make landfall at Taddiford Gap on Hordle Cliffs between Barton-on-Sea and Milford-on-Sea in Christchurch Bay and connect to onshore cables in an underground cable transition bay.

• A proposed underground 35km (22mile) cable route, 40m wide (the size of an 8 lane motorway) would carry these cables to a new onshore substation close to West Moors and Three Legged Cross, north of Ferndown.
  
• The electricity would then be transformed up to 400kV and connected to the adjacent Mannington substation, owned by the National Grid.

For a map of the proposed cable route click here.
You will need to enlarge the map to view where the route crosses SSSIs and Special Protection Areas.

Please see more information about the construction and concerns further down this page.

Construction works

Landfall

NBDL estimates that the construction works at the Landfall would take up to four months.  A temporary 6m access road from the B3058 (Milford Road) and a temporary compound (maximum 1ha, or 2.5 acres) would need to be built.  An underground cable transition bay would connect the offshore cables to the onshore cables.

Cable Route

NBDL estimates that 85% of the cable route would be open cut trenches, which would be subsequently backfilled.  The remaining 15% would be installed using trenchless technology, for example horizontal drilling.  Cables would cross

• 6 SSSIs, four International Conservation Sites and the New Forest National Park
  
• a number of major roads (including the A31) and 23 minor roads
  
• the SW Mainline railway
  
• major watercourses, including the river Avon, the Moors River and a number of minor watercourses
  
• rights of way, footpaths, private roadways and areas of woodland
• 129 hedgerows
  

There would be up to 56 site access points and up to 7 temporary construction compounds.

The proposed 130ft wide (40m) construction corridor (including the cable trenches, temporary access track and storage area for soil) would be the width of an 8 lane motorway, plus hard shoulders.  This would mean a working area of 40m x 35km, equivalent to over 1,800 football pitches.   We understand that no other developer of a large offshore windfarm has yet run their cables to a sub-station so far inland. 

Although the primary construction would be planned to take 2 years, the entire program could take up to 4.5 years, with consequent disruption and additional traffic movements.   The constuction would leave a scar on the landscape for many years.

Substation

NBDL estimates that the construction would take between 18 - 24 months.  There would be a maximum footprint of 4ha (just under 10 acres) and the design is yet to be finalised.

Concerns

There remain many questions still to be answered involving the environmental impacts including

• possible destabilisation and contamination of rivers, bogs and mire habitats
• erosion risk at Taddiford Gap
• impacts on mammals, reptiles and local birds, including nesting nightjars
• the impacts on 6 SSSIs - Highcliffe to Milford Cliffs, River Avon System,  Holt and West Moors Heath, Moors River System, St Leonards and St Ives Heath, Avon Valley 
• the impacts on 4 International Conservation Sites - Avon Valley Ramsar site, River Avon Special Area of Conservation (SAC), Dorset Heathlands Ramsar site, Dorset Heaths SAC
• the felling of many existing mature trees
  
• the impact on communities at Hordle, Bashley Park, Hinton, Three-Legged Cross, Ashley Heath and West Moors, individual farmsteads and small hamlets between Sopley and Bransgrove during construction
  
• the impact on local business and tourism during construction
  
• the loss of popular amenity areas during construction
  
• detailed traffic impacts of 44 tonne articulated HGVs on unsuitable rural roads and routes during construction
  
• disturbance of existing utilities during construction
  
• light, noise and vibration pollution, possible flooding during construction
• the possible effects from electro-magnetic fields and heat from the underground cables on the local ecology during operation
  
• the effects of leaving cables and ducts in the ground after decommissioning