Committee Report NSC

6.3

 
North Somerset Council

 

REPORT TO THE PLANNING AND REGULATORY COMMITTEE

 

Date of Meeting: 5 December 2012

 

Subject of Report: NATIONAL GRID PROPOSALS

 

Town or parish: Banwell, Sandford, Loxton, Christon, Winscombe, Yatton, Congresbury, Weston-super-Mare, Puxton, Churchill, Kenn, Tickenham, Nailsea, backwell, Wraxall, Clapton-in-gordano, portbury, portishead, Easton-in-gordano

 

Officer/Member presenting: Graham Quick, Local Planning Team Leader

 

Key Decision: No

 

RECOMMENDATIONS

 

That National Grid be informed that:

 

(i)         the undergrounding of the draft route through the Mendip Hills AONB and the second 132 KV line from Nailsea to Portishead sub station be welcomed;

 

(ii)        the Council will continue to work with National Grid to ensure the adverse environmental, social and economic impact of the new 400kv line and associated works throughout North Somerset is minimised wherever possible;

 

(iii)       the Council re-iterates its support for the proposed siting of the Sandford Sub station and strongly suggests that this is a gas insulated, grass roofed with measures to assist bat roosting/foraging. In addition the detailed design and layout should allow for a more direct alignment of the nearby Strawberry Line cycleway;   

 

(iv)       the preferred route corridor for the new 132 kv link to Weston-super-Mare is supported and that this should be undergrounded to minimise any impact on the level landscape;

 

(v)        further investigations should be undertaken to assess the impact on the residents of Moorland Park Congresbury with a view to moving the line further east;

 

(vi)       more work needs to be undertaken to assess the impact on the setting of Tickenham Court;

 

(vii)      the full impact on Portbury and Sheepway needs to be assessed and mitigated by careful pylon design and positioning;

 

(viii)     North Somerset Officers will continue to work with National Grid in order to identify appropriate mitigation measures and fully assess the impact of the draft route on key environmental concerns.

 

1.               Summary of Report

 

National Grid has announced the draft route for the new 400,000 volt power connection between Bridgwater and Seabank near Avonmouth. This has followed nearly three years of planning and listening to the views of local people and experts. It puts a line on the map for the connection needed for the new Hinkley Point C power station and other low carbon electricity generation planned for the South West.

 

This report explains the background to the project, sets out the current planning policy, previous Committee resolutions and highlights the key features of the exact alignment. It concludes with a set of key recommendations to be forwarded to National Grid.   

 

2.               Policy

 

The 2008 Planning Act introduced a new planning system for applications to build nationally significant infrastructure facilities in England and Wales. The new system covers applications for major energy generation, railways, ports, major roads, airports and water and waste infrastructure. Under the new system, national policy on infrastructure will be set out in a series of new National Policy Statements (NPS).  The Secretary of State will examine and decide applications for new infrastructure development, using the criteria on national need, benefits and impacts set out in the NPS, and consideration of evidence put forward on potential local effects.

 

The most relevant NPS is EN-5 on Electricity Networks where the use of the “Holford Rules” to guide the routing of overhead lines is recommended.  These state that routing should:

 

  • avoid altogether, if possible, the major areas of highest amenity value,

by so planning the general route of the line in the first place, even if total

mileage is somewhat increased in consequence;

  • avoid smaller areas of high amenity value or scientific interest by

deviation, provided this can be done without using too many angle towers,

i.e. the bigger structures which are used when lines change direction;

  • other things being equal, choose the most direct line, with no sharp

changes of direction and thus with fewer angle towers;

  • choose tree and hill backgrounds in preference to sky backgrounds

wherever possible. When a line has to cross a ridge, secure this opaque

background as long as possible, cross obliquely when a dip in the ridge

provides an opportunity. Where it does not, cross directly, preferably

between belts of trees;

  • prefer moderately open valleys with woods where the apparent height of

towers will be reduced, and views of the line will be broken by trees;

  • where  the country is flat and sparsely planted, keep the high voltage lines

as far as possible independent of smaller lines, converging routes,

distribution poles and other masts, wires and cables, so as to avoid a

concentration of lines or “wirescape”; and

  • approach urban areas through industrial zones, where they exist; and

when pleasant residential and recreational land intervenes between the

approach line and the substation, carefully assess the comparative costs

of undergrounding.

 

Although Government expects that the development of overhead lines will often be appropriate, it recognises that there will be cases where this is not so. Where there are serious concerns about the potential adverse landscape and visual effects of a proposed overhead line, these will have to be balanced against other relevant factors, including the need for the proposed infrastructure, the availability and cost of alternative sites and routes and methods of installation (including undergrounding).

 

EN5 states that the impacts and costs of both overhead and underground options vary considerably between individual projects. Therefore, each project should be assessed individually on the basis of its specific circumstances and taking account of the fact that Government has not laid down any general rule about when an overhead line should be considered unacceptable. Consent, however, should only be refused for overhead line proposals in favour of an underground or sub-sea line if the benefits from the non-overhead line alternative will clearly outweigh any extra economic, social and environmental impacts and the technical difficulties are surmountable.

 

Local Policy

 

There is no Council policy on the siting of overhead electricity lines although the North Somerset Replacement Local Plan and Core Strategy contains policies that seek to protect residents from harmful environmental effects and also protect the landscape from inappropriate development.

 

Previous Committee resolutions

 

When the initial consultation on three possible route corridor options took place the Planning and Regulatory Committee on 26 November 2009 resolved:

 

(i)         that bearing in mind any overland route would cross open countryside and close to residential properties and would therefore impact on landscape, ecology, an Area of Outstanding Natural Beauty and Sites of Special Scientific Interest, the National Grid is recommended to fully investigate the option of routing the lines along the seabed of the Bristol Channel as no explanation has been given as to why this route has not been considered;

 

(ii)        that subject to the above and subject to consideration of routing of cables next to the M5 motorway having been considered and there being no other option than to put up overhead lines and pylons, the Council’s preferred option is Option 1A, replacing the 132 KV line through the district with a 400 KV line, with the undergrounding of the overhead line route through the Mendip Hills Area of Outstanding Natural Beauty; and

 

(iii)       that the National Grid be requested to continually involve the Council in the process of determining the exact alignment of the overhead lines, the siting of new pylons and the process of removing existing pylons.

 

Following complaints about the lack of information on why the possibility of either a seabed or undergrounding route did not form part of the options, National Grid undertook further consultation in 2010 setting out additional information on these two approaches. This matter was discussed again at the Planning and Regulatory Committee on 21 July 2010 when it was resolved that:

 

(i)         None of the options put forward by National Grid are acceptable on the grounds that they will have an unacceptable impact on the countryside, natural environment and residents of North Somerset;

 

(ii)        National Grid is requested to continue to explore ways of overcoming the technical difficulties of subsea connections on the transmission network;

 

(iii)       The environmental consequences of the export of large amounts of electricity on the rural countryside are brought to the attention of Central Government.

 

Earlier this year the Planning and Regulatory Committee on 25 July discussed the various options needed around the Sandford/Churchill area to guarantee local electricity supplies and ensure that local homes and businesses remain connected. These options included a new sub-station north of Sandford to ensure that safe and reliable electricity supplies can be maintained once the existing 132kV WPD line is removed.

 

The Committee resolved that:

 

(i)         the proposed sub-station site west of Nye Road, Sandford is the preferred site and any landscape and biodiversity impacts be mitigated by designing the whole sub-station as a Gas Insulated station with extensive landscaping and bat roosting features and swallow ledges;

 

(ii)        the National Grid’s preferred option of Route B for overhead works with wooden poles is acceptable. Undergrounding would have significant extra landscape benefits but there would be severe considerations for archaeological and biodiversity interests which would have to be addressed if this option was chosen; 

 

(iii)       it is critical that the character of the Mendip Hills Area of Outstanding Natural Beauty, the Tickenham Ridge and the open views across the levels from the settlements of Nailsea, Tickenham and Yatton are protected. In addition, any adverse impacts on archaeological/biodiversity interests need to be taken into account when considering any undergrounding works.

 

3.               Details

 

Background

 

Since the preferred route corridor announcement in September 2011, National Grid have been working to develop the detail of the proposed 400,000 volt (400kV) connection between Bridgwater and Seabank.

 

In September 2011 they came forward with a preferred route corridor which was primarily based on the existing 132 KV line through the district.  This corridor varied in width – as wide as 1 km on the levels landscape close to Yatton and Nailsea to a very narrow corridor (300 m) through the Loxton Gap where the options for different routing is limited. They have been working closely with Local Authority officers and local councils to identify the many environmental constraints, features of interest, viewpoints etc. along the whole length of this corridor.  

 

In summer 2012 National Grid also consulted on proposals to reconnect the local electricity

distribution network in the Sandford/Churchill area, which would be disconnected as a result of the proposals to remove the existing 132kV overhead line and replace it with the proposed new 400kV transmission connection. This involved a number of sub station site options and methods of connecting to the 400kv network

 

On 6 November 2012 a further milestone was reached when National Grid announced the draft route for the proposed connection. This describes where they propose to remove existing overhead lines, and build a new connection. This line on the map also includes any areas where the use of underground cables can be justified. The details do not show the exact location of pylons nor the form of any mitigation measures e.g. landscaping, habitat creation etc that may be appropriate to offset the impact of their proposals 

 

This work continues Stage 3 of National Grid’s approach to the design and routeing of new electricity transmission lines and the consultation period runs from 6 November to

18 December

 

Details of draft route

 

As explained earlier in the report, the draft route broadly follows the existing 132KV line which will be removed. It is predominantly overhead with the exception of a five mile stretch in the Mendip Hills AONB .Plans will be displayed at the meeting.

 

General points regarding the route are:

 

(a)       The National Grid will take down the existing 132kv overhead line and replace it with the new 400,000 volt overhead line, therefore minimising the scale of change on the existing landscape;

 

(b)       National Grid have aimed to keep the overhead line as straight as possible to minimise the visual impact. Where an overhead line changes direction, the pylons are often larger and bulkier, and therefore have more visual impact. As a rule of thumb, the more severe the angle, the bigger the pylon;

 

(c)        In total National Grid expects there to be a reduction in the number of pylons between Bridgwater and Avonmouth from 240 to 145- although the height, design and positioning have yet to be determined.  As a” rule of thumb” there will be three pylons per kilometre. The height of the pylon will be largely determined by its design. If the new “T” pylon is used the height will be between 30 and 35 metres, while the more traditional lattice design will be 46-47 metres in height. Further consultation will be undertaken by National Grid on this issue.

 

(d)       At this stage no specific mitigation measures e.g. landscaping, habitat creation are put forward. However National Grid will be working during 2013 in formulating with interested stakeholders specific mitigation measures to offset the environmental impact of the transmission proposals;

 

Site specific points running from south to north are as follows:

 

(i)         The draft route will be undergrounded in the Mendip Hills AONB for a distance of 5 miles between just south of the Loxton Gap (in Sedgemoor) to just north of Sandford. The trenching work will be a maximum of 65 metres wide and will require extensive archaeological evaluation;

 

(ii)        A sealing end compound (a special pylon required to transfer an overhead line to an underground cable) will be required 1.5 km south of the Webbington M5 Bridge: (outside of the AONB);

 

(iii)       To avoid the need for two sealing end compounds, the underground cable will connect directly into the proposed substation near Sandford. This substation in the area west of Nye Road, Sandford is consistent with the Council’s views (P & R Committee 25 July 2012) and will mean no extra 400,000 volt overhead lines to connect the new substation. Details of the design, size and scale of the new substation will be the subject of further consultation;

 

(iv)       The chosen route corridor (B) for the new 132 kv link to Weston-super-Mare avoids important environmental areas and homes more than other routes considered and was the route favoured by the P & R Committee on 25 July 2012.  This corridor allows the removal of 1.2 kilometres of the existing overhead line connecting to Weston-super-Mare. Details of this new connection (underground or overhead/lattice pylons or wooden poles) will be the subject of further consultation;

 

(v)        From Nailsea northwards the second existing 132kv overhead line will be removed and placed underground between a point (yet to be determined) south west of Nailsea and Portishead substation- a distance of about eight miles.  The result will be fewer overhead lines in this area and the removal of pylons/lines which are very close to residential properties. Details of how these lines are going to be undergrounded will be subject to further consultation. The width of any trench work will be approximately 10 metres and could be accommodated within existing roads

 

(vi)       National Grid consider that the draft route is as far from the west of Nailsea as possible without affecting Tickenham. The new overhead line will be approximately 0.5 km away from existing residential properties. The existing two 132kv  lines are very close to existing properties and in some instances the lines and apparatus over sail rear gardens;

 

(vii)      Both of the existing overhead lines that cross Tickenham Ridge will be removed resulting in fewer overhead lines and pylons in this area;

 

(viii)     The route across the Tickenham Ridge takes advantage of the woodland which will provide some ‘screening’ and a backdrop for the overhead line. It also avoids Priors Wood the ancient woodland;

 

(ix)       The line avoids unnecessarily diverting towards Portishead substation and instead takes the most direct route available - running parallel to the M5 and then the Portishead to Bristol railway line. This chosen alignment avoids effects on Portbury Wharf Nature Reserve and means that the 400kv overhead line will be kept away from houses on the edge of Portishead. The line significantly deviates from the preferred route corridor and results in a 1 km reduction in the length of the line and also the number of angle pylons. However, this deviation results in the line being a lot closer to Portbury village and Sheepway and this is discussed under the key issues.

 

Key issues

 

The key issues that need to be addressed relate to the impact on landscape, biodiversity historic assets including archaeology sites and historic buildings, public rights of way and proximity to residential properties.

 

Very often the positioning of individual pylons will be absolutely critical to their impact on these key issues.  At this stage therefore it is only possible to comment in the most general terms on the potential impact of the scheme.

 

In certain instances the methodology used to assess the impact on key issues is unclear. There is often very little justification or evidence relating to the draft route chosen. As a result it is difficult to assess what factors have influenced the exact alignment chosen and what effect this alignment has on the setting for example of a historic building (Twickenham Court) or landscape. All historic assets seem to have the same significance and there is a lack of assessment relating to conflicts between interests, e.g minimize effect on the landscape whist affecting archaeological interests.

 

These issues will need to be addressed early in the next stage, although there is concern that to meet the National Grid timetable of submitting a Development Consent Order insufficient time will be available to undertake the necessary surveys/research for the Environmental Impact Assessment.

 

(a) Landscape impact

 

Mendip Hills AONB – Study Area C

The Mendip Hills Management Plan 2009-2014 cites the avoidance of damaging visual intrusions, including overhead power lines, in unsympathetic locations as one of a number of criteria in the planning decision making process.  The National Grid have followed both the Holford Rules and local policy in this respect and proposed under-grounding of the cables through the AONB.  This broadly follows the route of the existing overhead line (to be taken down).There will be significant visual post construction benefits in that there will no longer be towers (pylons) through the Lox Yeo Valley as at present. 

 

The southern cable sealing end compound is proposed to be sited in an area of three fields 1.5km south of the Webbington M5 bridge.  This is likely to be approximately 70m by 30m.  There is an existing vegetated embankment to a motorway bridge carrying a farm track to the north of this site.  Although the general landscape character is one of quite open pastoral fields and hedges with relatively few trees the area chosen does afford the best location for existing and future screening

 

Further tree and hedge planting would be required (particularly for the M5 boundary and to ensure views of the compound from elevated land in the AONB are screened as far as possible).  Site specific studies will need to be carried out to determine the best position (within the identified area) for the pylon and compound.  Input into proposed mitigation proposals will also be needed once technical details are progressed. 

 

Pylon design will also need careful consideration where they continue in view across the Somerset Levels.  Assessing the pylon options and precise locations (there is still scope to move the route alignment in critical locations) will be part of the future work with National Grid

Following construction the landscape will be restored through mitigation measures (yet to be agreed) insofar as this is possible.  Whilst hedges and walls can be replaced in the corridor, trees cannot as access to the cables may be required in the future and root growth can damage cables

Sandford Sub-Station and the North Somerset Moors – Study Area D

To avoid a further cable sealing end compound to the north the underground cable is proposed to be connected directly into the proposed sub-station north of Sandford.  Whilst the design has yet to be confirmed, the Council’s preferred option is for a gas insulated sub-station, one contained in a building designed to respect the environmentally sensitive location.  The suggestion has been put forward that a grass roofed design be explored, if this option is progressed. 

 

The scale of the sub-station is yet to be determined, but it is likely to be sited in the north-east corner of the identified site as there is a natural dip in the landform (near Droveway Bridge).  This also sites it as far away from residential property as possible.  Delivery of the missing link in the Strawberry Line railway walk near Droveway Bridge should also be explored as part of this proposal  

 

Extensive landscape mitigation combined with an environmentally sensitive building will be required in this rural location.  Landscape mitigation could include native trees and hedges, orchard planting, water bodies (rhynes or ponds) and limited landform alterations (particularly where needed to help integrate any building). 

 

Moving northwards care has been taken to select a route which minimises the impact of the new pylons and lines on residential areas.  Taking a route that moves the 400kv line further into Nailsea Moor, will however have greater landscape implications, because the moor is more open, with larger fields and fewer tall hedges and trees to assist screening.  Here great care will be needed in the siting and design of pylons.  Tower height is likely to be an important issue, if these structures are not to dominate this very open landscape.  Keeping the line as straight as possible is to be welcomed as this will reduce the need for larger angle towers. 

 

Minimising the construction impacts upon the SSSI (rivers, rhynes and associated buffers) will also be important, as the technical details evolve.  Where crossing the SSSI, for obvious ecological reasons, it has been suggested that towers will occupy the centres of fields.  This may not be the most sensitive option in terms of the visual impact and their may be cases where there is an over-riding landscape reason not to do this. 

 

The view north, down the Causeway to the Tickenham Court complex and St. Quiricus and St.Julietta’s Church (Listed Buildings) is important.  Here care needs to be taken to ensure that the towers and lines do not intrude into this view.  The reverse view (near the church) also needs to ensure that the lines blend into the backdrop of trees around the edge of Nailsea as far as possible. 

 

Because the second 132kv line will be under-grounded from a point south west of Nailsea (yet to be determined) to Portishead sub-station, there will be fewer overhead lines in this area.  The north west edge of Nailsea and Stone Edge Batch (where lines are very close together, due to the narrowness of the corridor), will benefit considerably from this part of the proposal. 

 

Residences in Nailsea, which are somewhat blighted by existing pylons adjacent to properties and lines over-sailing gardens, will benefit considerably by their removal or under-grounding.  It is hoped that the 132kv line can be routed primarily through existing roads, further helping to safeguard the nearby moors.

 

Tickenham Ridge – Study Area E

 

As both 132kv lines are to be taken down (one under-grounded) there are benefits arising from the reduction in the number of towers and lines visible crossing the ridge.  There is however a limited corridor (mainly constrained by avoiding the woodland) in which the ridge can be crossed.  The proposal follows one of the 132kv line routes, then crosses Caswell Hill and the M5, here it deviates to follow the motorway along an alternative route avoiding the Portishead sub-station. 

 

Portishead – Study Area F

 

There are considerable visual benefits arising in the Gordano Valley as a consequence of the alternative routing described above for the 400kv line and the under-grounding of the 132kv line, as no above ground lines will cross the valley. 

 

Where the 400kv line enters the valley, it will still cross the open hill slope west of Prior’s Wood, where the towers are seen against the sky (when looking south west from the pedestrian bridge over the M5 at Portbury).  There are some improvements to the alignment here, but there is a strong argument to avoid substantially increasing the pylon height here (whichever route option is selected).   

 

The 400kv line now avoids unnecessarily diverting towards Portishead substation and instead takes the most direct route available. This results in fewer towers and the least visual impact.  Running parallel with the M5 helps to minimise effects on views from Portishead and keeps the line away from numerous houses on the edge of Portishead.  The pylons following the relatively open land, running roughly parallel with the motorway, are likely to be very apparent and again there would be a strong argument for using the shortest tower possible. 

 

The line will run closely between the village of Portbury and the hamlet of Sheepway (very close to the Elm Tree Park, mobile home site), albeit within a heavily used road corridors of the M5 and A369.  This revised route will be very apparent from the M5 and where it crosses the A369 near the Sheepway junction, so again careful pylon placement and design will be important. 

 

From the village, there are a number of predominantly two storey dwellings, which have views (mainly to the rear), over the motorway.  Some of these properties to the south of the village are slightly more elevated.  Looking at the likely pylon locations, there appears to be a strong probability that a pylon would be located near the pedestrian bridge mentioned above.  This is a very prominent location (seen from the village and the bridge itself) and the detailed tower location study should seek to avoid this site entirely. 

 

Where the lines cross into the dock land they move further away from the village behind a belt of trees north of the A369.  Nevertheless, the potential height of the pylons and lines will require further careful visual study from the church grounds, school and High Street.  The setting of the Grade I church, being a particularly important issue. 

 

Avonmouth – Study Area G

 

Here green corridors and open storage areas within the dock are utilised to carry the lines around and through this intensively used area.  The openness of the environment (particularly the storage areas) and the high level views from the M5 Avonmouth Bridge mean that much of the line will be visible here.  However it is seen in a highly industrialised context with numerous other tall structures, such as lighting columns, cranes and large buildings. 

 

One existing 132kv line within the dock will be removed, providing a benefit to some houses and a school in Avonmouth, as well as providing some visual improvements within the Portbury Dock area and Parish Wharf.  Shorter pylons will also be used where the 400kv lines span the river. 

 

(b) Biodiversity Impact

 

The detailed alignment affects a number of designated Wildlife Sites (one in study area C, four in study area D, plus two SSSIs, one in area E, three in area F and one in area G).  .  As requested by the Council's ecologist, National Grid have sought to minimise impacts on designated Wildlife Sites as well as other designated sites.  One of the key principles with the overground sections will be to minimise ecological impacts by carefully siting pylons to avoid designated Wildlife Sites, and as far as possible rhynes, rivers, hedgerows and other sensitive ecological receptors revealed by ecological surveys.  Wildlife Sites are protected by policy ECH/14 in the Adopted Replacement Local Plan and therefore a buffer of at least 5 metres should be provided to retain the value of Wildlife Sites.  Within this buffer there should be no damaging works, storage of materials or pollution allowed to damage the sites.  

 

Where overgrounding is taking place temporary bridges or similar will need to be placed over rhynes (and rivers) to protect them and an appropriate buffer area (because legally protected species such as water voles and their burrows may be present on the banks) to minimise ecological impacts.  The location of site works compounds should also take into account ecological considerations, as should the construction haul route.  Where hedgerows and trees need to be removed they should be replaced with compensatory planting

 

Where undergrounding is to be undertaken which affects designated Wildlife Sites, ecological mitigation should be developed in the form of detailed ecological mitigation method statements.  It is hoped that horizontal directional drilling will be used with respect to rhynes and rivers.  Measures need to be taken to minimise ecological impacts from the substantial (e.g. 65 metre wide) wayleave that undergrounding entails and associated site compounds.

 

Buffers of tall vegetation should also be provided around relevant wildlife habitats.  This accords with the guidance in Biodiversity and Trees, the Supplementary Planning Document for developments within North Somerset, section 8.4, page 13, which states that, 'At least a five metre strip and sometimes a 10 metre strip for all water courses, hedges and woodlands should be retained to allow for management.  However, where the Internal Drainage Board maintains the rhynes, an eight metre maintenance strip must be included.'

 

As regards the proposed Sandford substation, there is an exciting opportunity to provide a bat roost (e.g. a potential warm maternity roost in a roof void) within the proposed building for horseshoe bats as a biodiversity enhancement.  This site is in close proximity to the Banwell Ochre Caves SSSI component of the North Somerset and Mendip Bats Special Area of Conservation.   This zone seeks to conserve the rare greater horseshoe bat which uses features such as hedgerows, woodland edges, ponds and wetlands, cattle grazed unimproved grassland and rough grass verges for foraging and also the lesser horseshoe bat.  Accordingly it would be desirable if compensatory tree and hedge planting on site with native shrub and tree species of local provenance was carried out to provide no net decrease (and ideally an increase) in the number of trees or the length of hedgerows on site.  Wherever possible hedges should be retained, and any losses made good by new planting, and a net increase in hedgerow length represents best practice. To benefit horseshoe bats, hedges should be interconnected and tall, with an average height of 3 metres, and broad (3 to 6 metres across); the height is important for bats which may use hedges as flight paths. 

 

Underpinning ecological survey data with respect to qualifying interest features needs to be assembled to provide underpinning data for a Habitats Regulations Assessments for the North Somerset and Mendip Bats Special Area of Conservation in the vicinity of the proposed Sandford substation and for the Severn Estuary European Marine Site where the proposed route crosses the River Avon.

 

(c ) Heritage Assets

 

Archaeological Impact

 

There are a number of policy references in the National Planning Policy Framework (para 126) Mendip Hills Management Plan (page 20) and the Core Strategy (Policy CS5) to protecting archaeological interests).  The archaeological response is to insist on a geophysical survey of the entire proposed corridor through the Mendip AONB. This will furnish a baseline from which appropriate archaeological mitigation can be designed.

 

The undergrounding in the Mendip Hills AONB will involve a trench 60 – 65 m wide .This will potentially destroy any sites of archaeological interest.   Therefore the required minimal archaeological programme will be

 

  1. A geophysical survey of the entire undergrounding corridor (including infrastructure at each end and any other attendant areas of disturbance such as construction camps, temporary access tracks and areas where former pylons are to be removed) should be the initial step to be undertaken.
  2. Based on the results of this survey, a series of evaluation by trial excavation trenches will be necessary, to define the date, nature and state of preservation of the archaeological sites and structures recognised
  3. Where sites are revealed to be sufficiently important, full excavation, recording, post-excavation and publication will be required
  4. Recognising the palaeoenvironmental potential of the Lox valley, all archaeological investigation will require environmental sampling, study and publication as routine
  5. All archaeological works in the programme will need to be carried out to a Written Scheme of Investigation agreed in writing with the LPA, and this must include post-excavation study and analysis and full publication.

 

Something similar (but obviously, on a smaller scale) may be required in the Tickenham ridge/Nailsea area as a result of undergrounding one of the existing 132 kv lines

 

Historic buildings and their setting

In general the impact of the scheme on Historic buildings and their setting will be dependant on the siting and design of individual towers. In general the route does not bring the pylon lines closer to designated heritage assets than the existing lines although obviously the increase in pylon height will have a greater visual and physical impact which will need to be assessed in further detail. However there are two areas of concern at this stage which it is worth commenting on in more detail.

 

Tickenham Court

Concerns regarding the impact on the significance of the Tickenham Court area have been expressed to National Grid from the very early stages of the scheme. Given the apparent complexity of this site a more detailed baseline assessment of the site will be required in order to gauge the impact of the scheme. As an ‘island’ in an area of marshy moorland the setting of this site is crucial to understanding its significance. As it stands the scheme will involve moving the line of pylons closer to the site, introducing taller pylons and constructing a large angle tower in close proximity to it.

 

Portbury

Of particular concern is the potentially harmful impact on the setting of the Grade I St Mary’s Church. The setting of this building has already been substantially harmed by the motorway however the English Heritage guidance on the setting of listed buildings is clear that previous harm does not justify further harm to setting. The overall impact of the introduction of a line of tall structures into what is generally a low-lying townscape and landscape is also of concern in heritage terms.

 

As it stands insufficient information has been provided to understand the impact of the proposal on the significance of designated and non-designated heritage assets. Given the nature of the scheme the impact on setting is potentially the most damaging element. Moving forward to a more detailed assessment of the impact on built heritage a more thorough assessment of the impact of the scheme, particularly on the setting of heritage assets, will be required for the Environmental Impact Assessment.

 

(d) Public Rights of Way

 

The current 132 kv line affects approximately 21 public rights of way and runs in close proximity to two other routes in the district. Given that the new 400kv line roughly follows 

the existing 132 kv line it will over fly a similar number of rights of way. Further discussion will be required with National Grid to ensure that wherever possible the new pylons avoid directly obstructing public rights of way on the ground.

 

The development of the Sandford sub station  does present an opportunity to provide a more direct link for the Strawberry Line and it is recommended  that this  be explored with National  Grid as part of the detailed discussions on the lay out and design of this structure.

 

(e) Proximity to residential properties

 

Many residents have expressed concern about the health impact of electro-magnetic fields (EMF’s) from high voltage overhead lines. In developing the draft route National Grid has sought to route as far as possible from residential properties on the grounds of general amenity. UK law does not prescribe any minimum distance between overhead lines and homes. National Grid does however ensure that all overhead lines are designed and built to comply with all relevant health and safety legislation. In the UK the Health Protection Agency has the responsibility to advise on standards of protection for EMFs. National Grid will as part of the Environmental Impact Assessment  undertake an assessment of the EMFs for the proposed new overhead line to ensure that any proposed route complies with the EMF exposure guidelines published by the International Commission on non-ionizing Radiation Protection (ICNIPRP) which are adopted by Government.

 

The undergrounding of the line through the Mendip Hills AONB and one of the 132 kv lines from Nailsea to Portishead realises significant benefits for those localities and their residents. In general, apart from three specific areas, the proposed line is not significantly closer to residential properties than the existing 132 kv line and in some instances the line has been purposely moved to increase distance away from properties. However the size of the pylons does mean that their overall impact can be greater even if they are further away from properties than existing structures.

 


 

Moorland Park, Congresbury   

 

The extension of this gypsy and traveller site was (subject to as yet unsigned Sec 106 agreement) granted temporary consent until 31 December 2013. The proposed line with its higher voltage and taller pylons runs very close to this site. Although the existing line is very close to the site, this exercise does give the opportunity to move the line further away from a substantial population.

 

Tickenham

 

Whilst the new 400kv line is further away from Nailsea than existing lines, the new alignment does bring power lines closer to Tickenham.  The impact on the Tickenham Court area has been discussed above  Given that the 400kv line  still will be 1km away from  properties in Tickenham it is considered that the impact on Tickenham residential  properties is not sufficient to outweigh the gains at Nailsea.  

 

Portbury

 

The draft route brings the 400kv line a lot closer to Portbury village and the hamlet of Sheepway (especially the Elm Tree Park, mobile home site), Whilst there are significant benefits to the wider landscape and ecology in this approach, the Council will need to work with National Grid to mitigate the effect on Portbury and Sheepway by careful, pylon position and design.

 

The next stage

 

Following any comments received on Stage 3 consultation National Grid will, in early 2013, consult with the Planning Inspectorate on the scope of the environmental impact assessment. They will also identify specific pylon positions and design, define the proposed sites for new substations and, sealing end compounds.

 

When this work is complete, they will announce their detailed proposals and this will

mark the start of Stage 4 of National Grid’s “Approach” during which full public

consultation, as defined by sections 47 and 42 of the Planning Act 2008, will be

undertaken. They expect to submit a Draft Development Consent Order to the Planning

Inspectorate towards the end of 2013.

 

The Planning Inspectorate has 28 days to assess the adequacy of pre-application

consultation. Assuming that this is deemed adequate, the application is accepted for formal Examination which must be completed with 12 months. A recommendation is then passed to the Secretary of State to make a final decision.

 

4.               Consultation

 

The Planning Act puts a stringent duty on National Grid to consult interested parties, including the public, local authorities and statutory bodies. If National Grid has carried out insufficient consultation, the application will not be accepted for consideration.

 

Before National Grid consulted the public, they developed a Statement of Community Consultation (SOCC) which sets out how National Grid will seek views. National Grid must submit a consultation report, outlining how consultation was carried out and recording responses from consultees. National Grid has shown commitment in seeking the views of all interested parties and has carried out a wide-ranging public consultation programme

 

National Grid have used a number of methods to engage statutory authorities, local authorities, local councils, pressure groups and the public. These include:

 

Thematic Groups

Convened around specific topic areas, these groups comprise statutory and non-statutory consultees and help to shape the surveys undertaken as part of the Environmental Impact Assessment and discuss their respective findings.

 

Community Forums

These are groupings of local representatives, convened by an independent chair, to raise issues of importance to the local community and challenge National Grid where appropriate.

 

Hinkley C Connection Group (HCCG)

National Grid attends quarterly meetings of the HCCG, which has been established and is organised by the affected local authorities, on an invitation basis. The HCCG includes key local authority officers and representative elected members, statutory and key non-statutory organisations, and a single nominated representative from a number of affected parish councils. New members must be agreed by the existing members. The HCCG meets to discuss Project related issues of common interest.

 

Parish and Town Councils

National Grid has a duty to consult with parish councils as prescribed statutory consultees.

National Grid have communicated with parish councils and offered meetings where appropriate. Around Project milestones and announcements National Grid have also organised ‘cluster’ meetings or briefings, where a number of parish councils are invited to the same event. Parish councils are invited to attend the Community Forums, and a number of parish councils have nominated a single representative to represent their views at the Hinkley C Connection Group (HCCG).

 

Affected landowners

In order to assist in the development of the detailed connection design for the Project, National Grid have identified and engaged with Persons with an Interest in Land (PILs) who may be directly affected by their proposals. This includes not only owners, but also tenants, occupiers and mortgagees, or anyone who exercises rights over the land in question, such as private rights of way or sporting rights.

 

Members of the public

Since September 2009 National Grid have been keeping the public informed by the following methods:

  • Press releases
  • Newsletters
  • Project Website
  • Project helpline
  • Public Drop in Exhibitions/Meetings 

 

The focus of  this consultation stage (Stage 3) is to encourage engagement and participation in activities that will help inform and develop National Grid’s proposals .Whilst not a formal stage of consultation as prescribed by the Planning Act 2008, National Grid considers this ongoing engagement a vital part of the wider consultation process. The following consultation arrangements have been put in place for the period up to 18 December:

 

  • Newsletter to all  residents within a defined Consultation Zone (40,000 copies)
  • Meetings with Persons with an Interest in the Land (Pills) (week beginning

      5 November)

  • Press releases
  • Local Authority Member Briefings (13 November for North Somerset)
  • Parish Cluster briefings (week beginning 12 November)
  • Local Community Forums  (week beginning 26 October)
  • Community Information Hubs (staffed exhibitions at Colliers Walk, Nailsea and Congresbury The Old School Rooms)
  • Information Points (Ayton and Portishead Library)
  • Hard copies of relevant documentation at Council offices and libraries
  • Project website
  • Project helpline
  • Twitter/Facebook networking

 

5.               Financial Implications

 

There are no financial implications. In accordance with government advice staff time and resources spent on this project are being reclaimed through a Planning Performance Agreement.

 

6.               RISK MANAGEMENT

 

Any delay in agreeing the exact alignment and the sub station siting could result in a consequential delay for National Grid in submitting their application in late 2013.

 

7.               Equality Implications

 

There are no equality implications.

 

8.               Corporate Implications

 

At this stage the exact siting of the required infrastructure is not known and therefore any implications for the Council’s land and buildings is unknown.

 

9.               Options considered

 

Since September 2011 National Grid have put forward a number of route corridor options and through a Strategic Option Report have justified why a number of possible options e.g. subsea, were ruled out on technical and cost grounds and not formally consulted upon. Earlier this year there were a number of options put forward for the sub-station in the Sandford/Churchill area and how this could be connected to the wider area.

 

At this particular stage there are no further options put forward by National Grid.

 

Author

 

Graham Quick 

Local Planning Team Leader

01934 426177


 

Background Papers

 

List of National Grid documents published on 6 November

 

Need Case for the South West and the South Wales and Gloucestershire Regions (October 2012): explains the need to increase the capacity of the transmission system in the South West, and in the South Wales and Gloucestershire areas.

 

Hinkley Point C Connection Project Connection Options Report: explains the draft route and various options examined.

 

Bridgwater to Seabank Feedback Report (Summer 2012): summarises the feedback from the summer 2012 consultation.

 

Local Electricity Network Preferred Options Report: This report explains where National Grid  propose to build the substation near Sandford which is required to keep the local electricity network in North Somerset connected to the high voltage network.

 

Local Electricity Network Consultation Feedback Report (Summer 2012): Summarises the feedback we received during the summer 2012 consultation on the proposed new substation near Sandford, and how it should be connected to the local electricity network.

 

Local Electricity Network Substation Siting Appraisal: outlines the preferred site for a substation to the west of Nye Road, Sandford.

 

Changes to the Hinkley Point Transmission Line Entry Points: Technical and Environmental Appraisal: explains what National Grid need to do at Hinkley Point in order to connect the new power station to the national electricity network.

 

Resolving Technical Issues in the South Wales and Gloucestershire Regions: explains why National Grid need a new substation at Aust and the options they have looked at.

 

Substation Siting Study for Options to Resolve Cable Overloads: outlines the options considered for a substation location in South Gloucestershire and identifies the location that would have the least impact on the environment.

 

“Project News”  - the newsletter.

 

Overview Report  - summarises information from the above documents.