Direct impacts on the seascape and landscape

Direct impacts on the seascape and on the landscape (for on-shore works). For example loss of landscape features or change in the character of the site itself resulting from ground disturbances, construction activity, lighting and presence of new features including but not limited to; access tracks, turbines, anemometry masts, substation, and offshore export cables/underwater cabling.

While there may be limited instances where offshore wind turbines are proposed for siting on or in close proximity to National Trust properties, there may still be direct impacts on the significance of a property where turbines are located in the ‘setting’. Understanding significance of the assets and the extent and nature of the setting is critical in order to make this judgement.

Indirect impacts on the landscape and seascape

Indirect impacts on the landscape and seascape character of the surrounding area – for example change in the character of adjacent landscapes as a result of the change in outlook from those landscapes.

The character of surrounding coastal landscapes and seascapes may contribute to the significance of the property. Note that direct impacts may occur where changes in the setting affect the significance of the property.

Direct impacts on views, daytime and night-time

Direct impacts on views, daytime and night-time – for example changes in views to and from NT properties and NT key views and vistas as a result of the introduction of tall moving structure(s) and construction activities into areas off the coast.

Cumulative impacts in combination with other existing or proposed offshore and onshore wind energy developments on landscape and seascape character and views

Cumulative impacts in combination with other existing or proposed offshore and onshore wind energy developments on landscape and seascape character and views (including combined visibility from a single viewpoint and sequential effects on routes).

Direct impacts on the seascape and landscape

Seascape, Landscape and Visual Impact Assessment (SLVIA). Effects on the special qualities, sensitivities and significance of the seascape, landscape, and/or property, considering the landscape value attached to NT properties and to their setting.

Assessment must consider both: offshore turbines and their effects on the special qualities, sensitivities and significance of NT coastal properties AND the onshore grid connection and its effects on the landscape and setting of NT properties. This will include night time effects of lighting on the seascape.

Analysis to be based on desk study, baseline assessment of the seascape and surrounding landscape, field study and photography. Consider whether a bespoke seascape character assessment is required at a detailed scale.

Use existing documents including Statement of Significance, Management Plans and other landscape evidence including Seascape Character Assessment. Consult seascape sensitivity/capacity studies where available to advise on the suitability of a selected site (while noting that they cannot be relied on in a regulatory capacity, and should only be used as a guide).

Indirect impacts on the landscape and seascape

Effects on the character and qualities of the seascape and coastal landscape and of the value provided to NT properties and their setting. Analysis to be based on desk study, baseline assessment of surrounding seascape and coastal landscape, field survey and photography.

Consideration of the significance of NT properties in proximity to and with views to the site, and their contribution to the surrounding seascape and coastal landscape character.

Use existing documents including Statement of Significance, Management Plans and other landscape evidence including Seascape and Landscape Character Assessments.

Direct impacts on views, daytime and night-time

Effects on views from the coast, considering size/scale, geographical extent, and duration of the effect. Analysis to be based on desk study, ZTV, wirelines and photomontages of agreed viewpoints, field study and photography.

Effects on key views and designed vistas as identified by the NT, considering the contribution of the seascape to the setting of any NT properties.

Potential receptors to assess include: visitors/tourists to NT properties including those travelling on routes to/from NT properties, users of sailing boats/ferries/kayaks/etc, residential receptors living within NT properties, recreational receptors on coastal long distance walking or cycling routes within or in proximity to NT properties.

Night-time visualisations may be provided in certain circumstances, for example in proximity to areas of dark night skies or where otherwise requested by the NT.

Cumulative impacts in combination with other existing or proposed offshore and onshore wind energy developments on landscape and seascape character and views

Cumulative effects on key views and designed vistas as identified by the NT, considering the contribution of the seascape to the setting of any NT properties.

Capacity of seascape to absorb new wind farm development.

Onshore grid/cable connection: Effects on landscape and setting of NT properties.

Direct impacts on the seascape and landscape

The initial site selection and layout should consider the capacity of the seascape and surrounding landscape to absorb offshore wind farm development, taking into account scale and character. Selected sites should carefully consider proximity to sensitive landscapes, including from NT properties and settlements. Consideration should be given to the significance of the property including key views and vistas, and the contribution of the seascape setting to significance, as outlined in NT documents.

Lighting is of particular concern in offshore developments due to the limited existing sources of artificial light, and care should be taken to minimise visibility of construction and turbine lighting in views from the coast.

For onshore elements:

Minimise the extent of disturbance to the ground and removal of existing vegetation. A landscape management plan or construction management plan should be developed jointly with an established landscape professional (and to be agreed on with relevant consultees, including NT, where necessary). The management plan should be in effect for the duration of the development.

Undertake landscape restoration works at the end of the construction period, ensuring any new planting or interventions are in character with the site and surrounding context, and enhance (or do not detract) from the significance of the property, in accordance with NT principles and associated management plans.

Indirect impacts on the landscape and seascape

Ensure careful design of turbine layout, considering impacts on views within, and in proximity to, the surrounding area and to the setting of NT properties.

Due to the expansive and often open nature of seascapes, micrositing of turbines to avoid visibility of turbines within key views is not likely to be as effective a tool. Initial site selection is most important for offshore wind.

Choice of appropriate turbine height, considering the scale and character of the coastal landscape in proximity. Consider the elevation of key views or landmarks along the coast, which would allow visibility of turbines from greater distance. Turbines should not appear overwhelming when seen in combined views with coastal landscapes or landmarks.

Direct impacts on views, daytime and night-time

Ensure careful design of turbine layout, minimising impact on views to and from NT properties, and considering scale within the seascape.

Micrositing of turbines to avoid key views.

Use appropriate colour coating for tower, nacelle, turbine blades and all ancillary infrastructure.

Achieve as consistent a height and spacing as feasible (in light of other constraints), to achieve a well-balanced composition overall.

Nacelle lights to be controlled by visibility sensors in order to reduce the intensity of the lights to approximately 10% of the minimum peak intensity in times of clear meteorological conditions (where visibility exceeds 5 km), which will substantially reduce the perceptibility of the proposed nacelle lights.

Follow an agreed ‘Construction Method Statement’ and ‘Construction Environmental Management Plan’.

Cumulative impacts in combination with other existing or proposed offshore and onshore wind energy developments on landscape and seascape character and views

Ensure careful design of turbine layout, considering stacking/curtain effects in combination with other existing or proposed windfarms, onshore and offshore.

Consider scale and number of turbines in relation to other existing schemes.

All impacts

For non – EIA development:

Appraisal of impact of proposal on seascape, landscape character and visual amenity.

For EIA development:

A SLVIA chapter within ES as set out in the Guidelines for Landscape and Visual Impact Assessment Third Edition (GLVIA3) must be prepared. Assessment of impacts on visual receptors to be agreed in consultation with NT. Key viewpoints to be agreed with Council, Natural England and Trust (where appropriate) at EIA Scoping stage. Turbines, offshore export cables and the corridor route, and the onshore grid connection should be included in the scope of assessment. NB: where appropriate, a developer may wish to present both an LVIA and SLVIA, with separate study areas.

Night-time lighting assessment (in addition to SLVIA). Night time lighting to consider effect on overall character (e.g. in remote seascapes/landscapes, dark sky reserves) as well as visual receptors.

Cumulative Landscape and Visual Amenity Assessment – assessment of additional cumulative effects that would arise when adding the Development to a baseline containing consented but unbuilt wind farms, and those that are the subject of a valid planning application within the 33 km search area (these equate to ‘Tier 1’ projects as set out in the Planning Inspectorate Advice Note 17).

Site selection and design chapter within ES: Setting out the rationale behind the site selection, design objectives, the design evolution in response to different sensitivities and constraints, and any potential mitigation strategies.

‘Construction Method Statement’ and ‘Construction Environmental Management Plan’ (CEMP) which should include arrangements for implementation of various aspects of the works. The statement should also set out restoration for onshore elements of landscape earthworks, soils and surface vegetation e.g. along cable routes once the construction phase is complete.

All impacts

Monitoring by Environmental Clerk of Works (ECoW) or other relevant landscape professionals to ensure restoration efforts are implemented as outlined in the CEMP. A landscape management plan should be agreed upon post-consent, providing further detail and guidance for the implementation and guidance of the CEMP. The landscape management plan should be in effect for the duration of the development, and appropriate monitoring is to be expected throughout.

Department for Energy Security and Net Zero (2023) Draft NPS for Renewable Energy.

Landscape Institute and the Institute of Environmental Management and Assessment (2013) Guidelines for Landscape and Visual Impact Assessment, Third Edition.

Landscape Institute (2023) Notes and Clarifications on aspects of the 3rd Edition Guidelines on Landscape and Visual Impact Assessment (GLVIA3).

Landscape Institute (2019) Visual Representation of Development Proposals – Technical Guidance Note 06/19.

White, S. Michaels, S. King, H. (2019) Seascape and visual sensitivity to offshore wind farms in Wales: Strategic assessment and guidance. Stage 1- Ready reckoner of visual effects related to turbine size; Stage 2- Guidance on siting offshore windfarms; Stage 3- Seascape and visual sensitivity assessment for offshore wind farms. NRW Evidence Series.

NECR 105 (Natural England). Broad brush guidance on seascape character assessment.

Natural Resources Wales (2018) Landscape Sensitivity and Capacity Assessment: Guidance for Wales and associated Annex 1, Draft for consultation.

Marine Management Organization (2018). Seascape assessments for North East, North West, South East, South West marine plan areas.

The Planning Inspectorate (2019) Advice Note 17: Cumulative Effects Assessment Relevant to Nationally Significant Infrastructure Projects.

Direct impact of construction/ scour protection on loss and displacement of ecological receptor

Offshore turbines: direct impact of construction/ scour protection on loss/displacement of ecological receptors (e.g. habitat loss such as benthic/seabed and intertidal and subtidal habitats and/or loss of plant or animal species/marine mammals, disturbance, fragmentation).

On-shore grid connection: Direct impact of grid connection construction and connection routes on loss/displacement of ecological receptors (e.g. habitats, notable or protected plant or animal species, disturbance, fragmentation of habitat, foraging areas).

Direct and indirect impacts on ecology receptors

Direct and indirect impacts on ecological receptors (e.g. disturbance of habitats/species from operational impact of offshore wind turbines and cable routes/landing areas, loss of food resources).

Opportunities for habitat management and enhancement

Opportunities for habitat management and enhancement, including biodiversity net gain (BNG).

Direct impact of construction/ scour protection on loss and displacement of ecological receptor

Offshore turbines/on-shore grid connection: Ecological Impact Assessment (as part of Ecology Chapter of Eira): assessment of impacts on offshore and on-shore ecology, biodiversity and the physical environment should be undertaken for all stages of the lifespan of the offshore wind farm, comprising the following:
– Desk Study
– Extended Phase 1 (or UK Habitat Classification System) Habitat Survey (extended to include potential for protected species).
– Ecological Impact Assessment (EcIA): including an assessment of the effects of installing cable routes across the intertidal zone.
– Protected species surveys.

On-shore grid connection – these can include: bats (activity surveys and emergence surveys); badger; otter; water vole; red squirrel; pine marten; reptiles; great crested newt; hazel dormouse; invertebrates; white clawed crayfish. European Protected Species License may be required to carry out work that may affect European protected species.
Offshore turbines – surveys include benthic survey of seabed habitat, benthic, fish and shellfish and marine mammals (and noise) survey (turbine locations and cable routes), at least 2 years worth of data required.

Habitat Regulations Assessment is required if European Wildlife Sites are impacted (terrestrial SPAs, SACs for on-shore grid connection, or SPAs/SACs with marine components impacted). Screening report may be required where SPA, SAC or Ramsar sites are within local area and their features may be impacted. Sites within 10km should be screened: sites up to 20km may also be impacted e.g. if watercourse affected downstream, or if bats are an important SAC feature and their commuting/foraging areas may include the site. If Screening shows that a ‘likely significant effect’ cannot be excluded (in the absence of mitigation), then an Appropriate Assessment (AA) is required. Note: ecological mitigation cannot be taken into account at Screening stage – mitigation is addressed at AA stage.

Direct and indirect impacts on ecology receptors

See above

Opportunities for habitat management and enhancement

Habitat Management Plan for on-shore elements. Biodiversity enhancement plans for offshore turbines location.

Direct impact of construction/ scour protection on loss and displacement of ecological receptor

Strategic planning: Site turbine and supporting on-shore infrastructure away from sensitive sites/habitats/species.

Cumulative effects need to be taken into account from other developments and plans. In combination effects should be assessed in relation to HRA assessment, taking into account impact and mitigation from neighbouring wind farms.

Containing work to minimise disturbance footprint.

Offshore turbines: species specific mitigation measures e.g. soft start piling and noise deterrent devices to reduce noise impact to marine mammals.
Onshore grid connection: species specific mitigation measures e.g. retention of trees and buildings with bat roosts, retention of bat foraging and commuting corridors; siting development at least 30m from active badger setts; siting development away from ponds and watercourses that may support otter (100-200m buffer for breeding dens; 30m for non breeding holts or shelters) or water vole (10m zone around active burrows) and ensuring best practice pollution control measures; siting development away from great crested newt ponds or associated terrestrial habitat; ensuring sufficient reptile habitat on site to allow habitat manipulation under ecological supervision. Red squirrel, pine marten and hazel dormouse unlikely to be impacted by on-shore grid connections – but if impacts likely then suitable woodland, scrub and hedgerow habitat should be retained.
Note: if HRA process identifies likely significant effects, but mitigation and alternatives do not resolve the impacts, and the project must be carried out for imperative reasons of overriding public interest, then there is a requirement that the appropriate authority must ensure that any necessary compensatory measures are taken to ensure that the overall coherence of the UK site network is protected (i.e. where a project is authorised in accordance with the derogation tests). Compensation can include (e.g.) fisheries management; improving or creating habitat outside of the SPA/SAC.

Direct and indirect impacts on ecology receptors

Protect water quality and quantity (e.g. prevention of pollution and sedimentation).

Maintain hydrological regimes.

Protect habitats used for foraging and shelter by fauna.

Note: if HRA process identifies likely significant effects, but mitigation and alternatives do not resolve the impacts, and the project must be carried out for imperative reasons of overriding public interest, then there is a requirement that the appropriate authority shall secure that any necessary compensatory measures are taken to ensure that the overall coherence of the UK site network is protected (i.e. where a project is authorised in accordance with the derogation tests). Compensation can include (e.g.) fisheries management; improving or creating habitat outside of the SPA/SAC.

Opportunities for habitat management and enhancement

Identify opportunities for habitat enhancement either on site (reinstating sediments from cable ploughing, articila reef creation).
BNG Mandatory biodiversity net gain introduced under the Environment Act 2021 requires that natural habitats will be extended or improved as part of a development or project. Development must be designed in a way that provides benefits to people and nature and reduces its impacts on the wider environment. Biodiversity net gain will apply to Nationally Significant Infrastructure Projects, including those in marine and intertidal habitats, with a specific marine net gain quantitative metric being developed.

All impacts

For non – EIA development:

Preliminary Ecological Appraisal should be prepared.

For EIA development:

An Ecological Impact Assessment (EcIA) will need to be included within the Ecology Chapter of an ES. The EcIA should contain details of Protected Species and Habitat/NVC/Peat Surveys where relevant.

Additionally, a Habitat Regulations Assessment: Screening Report and Appropriate Assessment will be required.

Additional documents include:

– Marine Biodiversity Net Gain assessment note (England) or Net Biodiversity Benefit assessment (Wales).
– Ecological Mitigation Plan and/or Habitat Management Plan. Environmental/Ecological Monitoring Programme.

Direct impact of construction/ scour protection on loss and displacement of ecological receptor

Ecological monitoring can include: fish species (importance defined locally, e.g. can include cod, herring, sand eels, diadromous fish species, e.g. salmon); benthic communities; sea bed scour and local sediment deposition; marine mammals (e.g. seals, dolphins, monitoring in response to acoustic deterrent devices).

Direct and indirect impacts on ecology receptors

See above

Opportunities for habitat management and enhancement

Management plans to include monitoring and review.

Department for Energy Security and Net Zero (2023) Draft NPS for Renewable Energy.

Welsh Government (2009) Technical Advice Note 5: Nature Conservation and Planning.

RSPB, WWF, English Nature and BWEA (2001) Wind Farm Development and Nature Conservation.

Natural England (2021) Approach to Offshore Wind. TIN181.

Crown Estate (2019) Guide to an offshore wind farm.

Defra, Natural England, Welsh Government and Natural Resources Wales (2021) Habitats regulations assessments: protecting a European site.

CIEEM (2018) Guidelines for Ecological Impact Assessment in the UK and Ireland.

CIEEM (2018) Guidelines for Preliminary Ecological Appraisal.

Marine Management Organisation (2014) Review of post-consent offshore wind farm monitoring data associated with licence conditions.

Nature Scot (2023) Advice on marine renewables development.

UK Government (2023) Biodiversity Net Gain Research.

Disturbance to breeding, passage or wintering birds

Disturbance to breeding, passage or wintering birds due to construction activity.

Direct or indirect habitat loss due to windfarm operation

Displacement – direct or indirect habitat loss due to wind farm operation. If birds avoid the wind farm and its surrounding area due to turbine construction and operation. Displacement may also include barrier effects in which birds are deterred from using normal routes to feeding or roosting grounds.

Collision risk

Collision risk – i.e. birds colliding with the turbine blades during operation.

All impacts

Offshore turbines/on-shore grid connection: Ornithological Impact Assessment (Ornithology Chapter of EIA): assessment of impacts on offshore and on-shore ornithology should be undertaken for all stages of the lifespan of the offshore wind farm, comprising the following:
– Desk Study

Boat/aerial/vantage point surveys of seabirds, breeding, passage and winter i.e. throughout the year: at least 2 years worth of data required. The priority species for assessment of displacement effects will typically be diver and sea duck species, guillemot, razorbill, puffin and gannet.
For all species requiring assessment, the wider zone of influence, which include impacts outside of the development footprint, should be considered. For most species the zone of influence will extend to 2km beyond the development footprint, however, there are some exceptions to this for more sensitive species (red-throated divers being 10km, and for other divers and sea ducks 4km).

Habitat Regulations Assessment will be required if European Wildlife Sites are impacted (terrestrial SPAs, marine SPAs, SPAs with marine components, Ramsar sites impacted). Screening report may be required where SPA and or Ramsar sites are within local area and their features may be impacted. Sites within 10km should be screened: sites up to 20km may also be impacted where an important site feature and their commuting/foraging areas impacted. If Screening shows that a ‘likely significant effect’ cannot be excluded (in the absence of mitigation), then an Appropriate Assessment (AA) is required.
Note: ecological/ornithological mitigation cannot be taken into account at Screening stage – mitigation is addressed at AA stage.

Collision risk modelling should also be prepared.

All impacts

Strategic planning: Avoiding location of turbines in areas with significant concentrations of birds (either breeding birds’ feeding grounds; large concentrations of wintering or passage birds (sea ducks, grebes, divers, gulls, terns etc). An assessment should include strategic planning and in combination effects. Cumulative effects need to be taken into account from other developments and plans. To adequately assess cumulative impacts of wind energy development on a marine bird species, we must understand the:
1) range of OWED impacts and how these affect demographic rates (e.g., mortality, decreased reproductive output, immigration, emigration),
2) expected scale of the industry at full buildout (e.g. number of developments, number of turbines),
3) proportion of population or species impacted, and
4) the impact of other stressors on demographic rates (e.g., introduced species, fisheries bycatch, shipping, climate change).
In combination effects to be assessed in relation to HRA assessment – taking into account impact and mitigation from neighbouring wind farms.

The primary approach to mitigate displacement impacts is to avoid areas with high densities of vulnerable marine birds. Avoid significant breeding, passage or wintering bird habitats/areas on marine, inter-tidal and terrestrial areas affected.
Where sites or features are impacted, mitigation can include:
– minimising the probability of collision by considering structural design (e.g. using distinguishing patterns and colours such as black-and-white bands, a single black blade, or blades painted with UV reflective colours), layout (e.g. height)
– Adjust turbine height to avoid risk to birds flying at lower levels), and operational schedule; the behaviour of vulnerable species; and environmental conditions during encounters.
Where impacts cannot be avoided or minimised, compensatory mitigation should be delivered. Compensatory mitigation can be used to offset residual impacts to achieve no net loss or even net gain of marine bird populations and may be the best approach to prevent cumulative impacts from causing population declines across regional and international scales. Examples of compensation (which may be appropriate at large distances from the development): invasive species removal at seabird breeding colonies; establishment of new breeding colonies (e.g. provision of artificial kittiwake nesting towers at coastal locations); influencing fisheries catches (i.e. reducing bycatch by regulatory change or bycatch reduction techniques).

All impacts

For non EIA development:

Preliminary Ornithological Appraisal.

For EIA development:

An Ornithological Impact Assessment should be included as an Ornithology Chapter of an ES (with Technical Appendices on survey methodology and results; collision risk modelling) setting out mitigation and compensation measures.
Additionally, if required, a Habitat Regulations Assessment (Screening Report and Appropriate Assessment) should be prepared.

An Ornithological Mitigation Plan and/or Habitat Management Plan and Ornithology Monitoring Programme may be necessary.

All impacts

Outline Ornithological Monitoring Plan.

In terms of the wider area, monitoring should help improve understanding of relevant seabird populations and their dependence on the zone of impact. Look at trends in population abundance (e.g. via contributions to key colony counts); collection of data on productivity and survival rates of key species; understanding connectivity and relationships between key sites and the impact zone (e.g. via tagging). For individual wind farms, monitoring should quantify flight behaviour of key species during the initial post-construction phase; collect digital aerial survey of key species within the wind farm site and buffer zone; and programme of tagging and tracking of key species (e.g. kittiwake, gannet) every 3 years alongside offshore bird surveys. Camera systems can be used/trialled to assess sea bird movements and collisions/near misses.

Department for Energy Security and Net Zero (2023) Draft NPS for Renewable Energy.

Nature Scot (2023) Advice on marine renewables development.

Defra (2015) Nature Conservation Guidance on Offshore Windfarm Development.

DCLG (2005) Planning Policy Statement 9 Biodiversity and Geological Conservation.

Crown Estate (2019) Guide to an offshore wind farm.

EC Council Directive on the Conservation of Wild Birds (Directive 79/409/EEC).

Langston R.H.W and Pullan J.D. (2003) Wind farms and Birds: An analysis of the effects of wind farms on birds, and guidance on environmental assessment criteria and site selection issues.

BirdLife International on behalf of the Berne Convention.

Defra, Natural England, Welsh Government and Natural Resources Wales (2021) Habitats regulations assessments: protecting a European site.

Joint SNCB1 Interim Displacement Advice Note: Advice on how to present assessment information on the extent and potential consequences of seabird displacement from Offshore Wind Farm (OWF) developments January 2017 (updated January 2022 to include reference to the Joint SNCB Interim Advice on the Treatment of Displacement for Red- Throated Diver)

Direct physical impacts to marine heritage assets

Direct physical impacts (loss or truncation) to marine heritage assets (wrecks, coastal an intertidal features, submerged archaeological deposits and features) and palaeolandscapes due to scheme groundworks. (Generally, no effect on Protected Wrecks or marine scheduled monuments would be acceptable.)

Assets and deposits may be subject indirect physical impacts once infrastructure is in place due to the way in which it can alter erosion/scour and scour patterns on the seabed.

Harm arising from changes in the setting of on-shore heritage assets

Harm arising from change in the setting of on-shore heritage assets, including designated assets (e.g. scheduled monuments, listed buildings, registered parks and gardens, registered battlefields, World Heritage Sites).

All impacts

Understanding of significance of assets potentially affected is vital prior to determining impacts/potential impacts. Historic environment desk-based assessment (HEA), in line with associated CIfA Standard and Guidance, informing ES chapter or as a standalone supporting document for the application (non-EIA cases) or other appropriate document (e.g. in Wales a Heritage Impact Assessment (HIA) following associated Cadw guidance is to be produced in the scenario that the application directly affects (i.e. is in) a historic asset).

Surveys to include construction areas and micrositing allowance, and prospection for assets potentially affected within the redline boundary. Designated assets to be assessed for sensitivity to the proposed change within the ZTV, along with non-designated assets of high importance. The potential for views of the development in combination with assets also need to be considered with the assistance of the ZTV.
Relevant survey is likely to include walkover survey of landfall footprint in intertidal zone, marine geophysical and geotechnical survey. Marine surveys are to cover realistic estimates of where the scour and burial regime may change as a result of presence of scheme infrastructure. Appropriate survey will enable proper understanding of the significance of assets subject to direct and indirect physical effects and fulfil information requirements for determination. This work is to be undertaken in line with relevant guidance (e.g. CIfA, HE).

Assessment methodology is to be in line with 2021 ‘Principles of Cultural Heritage Impact Assessment in the UK’, as industry-standard guidance developed and promoted by the relevant professional institutes for the historic environment and EIS. It is to meet relevant Historic England or Cadw guidance. Assessment of heritage significance should be transparently articulated (i.e. in line with Historic England or Cadw ‘Conservation Principles’, or equivalent heritage values set out in national planning polices (e.g. NPPF)). The assessment is to use a transparent articulation of impacts and effects, making it clear what effects are significant effects in EIA terms and why, to enable consistent judgement across topics. In England, these are to be expressed in terms of whether and what level of harm arises so the tests in NPPF can be applied by the decision maker.

Clear evidence of the design process and solutions explored to avoid/minimise effects are to be provided in the ES and DAS.

Direct physical impacts to marine heritage assets

Design wind farm and cabling connections to avoid physical impacts on identified heritage assets. Design wind farm layout to avoid impacts and preserve features in situ wherever possible.

Harm arising from changes in the setting of on-shore heritage assets

Given the scale of offshore developments, it is unlikely that the locations of individual turbines will make any difference to the effects to onshore assets.
It would be rare that an offshore development would give rise to substantial harm to onshore assets as a consequence of setting change. It would need to affect a relationship that was so fundamental to an asset’s significance that it would equate to loss, or near-total loss of that relationship and the ability to understand and appreciate its significance.
The Trust’s focus may therefore be best applied to securing onshore offsetting of any harm identified.

All impacts

It is highly likely that all offshore wind would be EIA development, consequently the following are required:

– Input on effects to historic assets prepared by historic environment specialist in Design and Access Statement.

– ES Historic Environment chapter covering marine and terrestrial assets.

– Appropriate supporting technical appendices (e.g. HEA (incl. setting assessment), marine geophysical survey report, marine geotechnical data review, geoarchaeological assessment, historic buildings assessment, HIA, WSI).

In general, the Town and Country Planning Acts apply on land and down to low water, with marine licensing applying in tidal waters up to high water (including large inland areas with tidal rivers/estuaries etc).Consent for development in the marine environment requires a Marine License and seabed lease so this would be required for marine geophysical surveys and marine geotechnical surveys.

All impacts

Monitoring by relevant curatorial authority (e.g. LPA archaeological advisor, conservation officer; HE/Cadw officer) to ensure agreed mitigation works are being undertaken in line with the approved WSI. This process may take several years where archaeological investigation is required as any specialist analyses and post-excavation works must be concluded before reporting can be completed and published, at which point the monitor certify that they have been completed in line with the WSI.

It is likely that the consenting process will require both bodies that cover onshore elements (such as HE, LPA etc) and those that cover tidal zones and offshore (such as the MMO (Marine Management Organisation) so applications will require input and crossover from both.

Chartered Institute for Archaeologists (CIfA) (2020) Standard and Guidance for historic environment desk-based assessment.

IEMA, IHBC & CIfA (2021) Principles of Cultural Heritage Impact Assessment in the UK.

CIfA (2020) Standard and guidance for archaeological geophysical survey.

CIfA (2020) Standard and guidance for archaeological field evaluation.

Historic England (2015) Managing Significance in Decision-Taking in the Historic Environment: Good Practice Advice in Planning Note 2.

Historic England (2021) Commercial Renewable Energy Development and the Historic Environment in Planning Note 15.

Historic England (2017) The Setting of Heritage Assets: Historic Environment: Good Practice Advice in Planning Note 3.

Historic England (2017) Ships and Boats: Prehistory to Present

Historic England (2019) Statements of Heritage Significance: Analysing Significance in Heritage Assets Historic England Advice Note 12.

Cadw (2017) Heritage Impact Assessment in Wales.

Cadw, Countryside Council for Wales & ICOMOS (2007) Guide to Good Practice on Using the Register of Landscapes of Historic Interest in Wales in the Planning and Development Process Second Edition.

Cadw (2017) Setting of Historic Assets in Wales.

Welsh Government (2017) Technical Advice Note 24: The Historic Environment.

Department for Communities (2018) Guidance on Setting and the Historic Environment for Northern Ireland

Department for Communities (2019) Guidance on making changes to Listed Buildings: Making a better application for listed building consent for Northern Ireland

Department for Infrastructure (2019) Best Practice Guidance to PPS 23 ‘Assessing Enabling Development for the Conservation of Significant Places

Department for Infrastructure (2019) Wind Energy Development in Northern Ireland Landscapes SPG

Department of the Environment (2009) Best Practice Guidance to Planning Policy Statement 18 ‘Renewable Energy’

Historic Environment Guidance for the Offshore Renewable Sector (Wessex Archaeology 2007)

Guidance for Assessment of Cumulative Impacts on the Historic Environment from Offshore Renewable Energy (Oxford Archaeology and George Lambrick Archaeology and Heritage 2008)

Offshore Geotechnical Investigations and Historic Environment Analysis: Guidance for the Renewable Energy Sector (Gribble and Leather, 2011)

Model Clauses for Archaeological Written Schemes of Investigation: Offshore Renewables Projects (Wessex Archaeology 2010a)

Protocol for Archaeological Discoveries: Offshore Renewables Projects (Wessex Archaeology 2010b)

Code of Practice for Seabed Development (JNAPC 2006)

Physical impacts to above-ground heritage assets (buildings, landscape components) and buried heritage assets

Physical impacts (loss or truncation) to above-ground heritage assets (buildings, landscape components) and buried heritage assets (archaeological deposits and features, including undiscovered archaeology and paleoenvironmental remains). Including from cable corridors crossing. NT land

Harm to the significance of impacts

Harm (negative impact) to the significance of assets arising from change in their setting (e.g. interruption of visual, functional, symbolic or historic relationships; effects as a consequence of noise, vibration).

NB. Effects as a consequence of setting change are direct, as they directly affect the heritage significance of the asset.

Harm to historic landscape character

Harm to historic landscape character.

All impacts

Understanding of significance of assets potentially affected is vital prior to determining impacts/potential impacts. Historic environment desk-based assessment (HEA), in line with associated CIfA Standard and Guidance, informing ES chapter or as a standalone supporting document for the application (non-EIA cases) or other appropriate document (e.g. in Wales a Heritage Impact Assessment (HIA) following associated Cadw guidance is to be produced in the scenario that the application directly affects (i.e. is in) a historic asset).

Is to include walkover survey of construction footprint, micrositing allowance, and prospection for assets potentially affected within the redline boundary, and zone of ZTV. May require evaluation field work (i.e. non-intrusive (geophysical survey); intrusive (trial trenching)) to fully understand significance of assets subject to direct physical effects and fulfil information requirements for determination. This work is to be undertaken in line with relevant guidance (e.g. CIfA, HE).

Assessment methodology is to be in line with 2021 ‘Principles of Cultural Heritage Impact Assessment in the UK’, as industry-standard guidance developed and promoted by the relevant professional institutes for the historic environment and EIS. It is to meet relevant Historic England or Cadw guidance. Assessment of heritage significance should be transparently articulated (i.e. in line with Historic England or Cadw ‘Conservation Principles’, or equivalent heritage values set out in national planning polices (e.g. NPPF)). The assessment is to use a transparent articulation of impacts and effects, making it clear what effects are significant effects in EIA terms and why, to enable consistent judgement across topics. In England, these are to be expressed in terms of whether and what level of harm arises so the tests in NPPF can be applied by the decision maker.

Clear evidence of the design process and solutions explored to avoid/minimise effects are to be provided in the ES and DAS.

All impacts

Design onshore infrastructure, construction compounds, lay-down space and ancillary off-site construction works (e.g. access improvements) to avoid physical impacts on identified heritage assets. Design onshore layout to avoid impacts and preserve features in situ wherever possible. Layout is to be informed by the use of ZTVs and appropriate visualisations (wireframes, and photomontages for the final ES) to enable design to minimise effects to heritage assets arising from change in their setting.

Where assessment suggests that archaeological potential is high, mitigation strategy is to be informed by field evaluation – geophysical survey (where ground conditions allow and such survey is warranted by the level of likely archaeological potential) and/or trial trenching, in line with an approved WSI. Where fieldwork is required on NT property then NT are to be a consultee on development of the WSI.

Where physical impacts to non-designated assets cannot be avoided, preservation by record can be acceptable, but must be undertaken in line with a Written Scheme of Investigation (WSI), approved by the LPA archaeological adviser, and by appropriately qualified and accredited archaeological professionals. The programme of fieldwork is to be secured by condition, and the necessary funding from the developer for analysis of excavation outcomes, analysis of environmental samples, finds etc., deposition of archive material and processed finds, and publication in a periodical commensurate with the significance of the evidence recovered, must be secured by legal agreement.

All impacts

It is assumed that all offshore wind would be EIA development, the following are required:

– Input on effects to historic assets prepared by historic environment specialist in Design and Access Statement.

– ES Historic Environment chapter covering marine and terrestrial assets.

– Appropriate supporting technical appendices (e.g. HEA (incl. setting assessment), geophysical survey report, trial trenching report, geoarchaeological assessment, historic buildings assessment, HIA, WSI).

All impacts

Monitoring by relevant curatorial authority (e.g. LPA archaeological advisor, conservation officer; HE/Cadw officer, HED) to ensure agreed mitigation works are being undertaken in line with the approved WSI and archaeological excavation license if required (for works in Northern Ireland). This process may take several years where archaeological investigation is required as any specialist analyses and post-excavation works must be concluded before reporting can be completed and published, at which point the monitor certify that they have been completed in line with the WSI.

Chartered Institute for Archaeologists (CIfA) (2020) Standard and Guidance for historic environment desk-based assessment.

IEMA, IHBC & CIfA (2021) Principles of Cultural Heritage Impact Assessment in the UK.

CIfA (2020) Standard and guidance for archaeological geophysical survey.

CIfA (2020) Standard and guidance for archaeological field evaluation.

Historic England (2015) Managing Significance in Decision-Taking in the Historic Environment: Good Practice Advice in Planning Note 2.

Historic England (2017) The Setting of Heritage Assets: Historic Environment: Good Practice Advice in Planning Note 3.

Historic England (2019) Statements of Heritage Significance: Analysing Significance in Heritage Assets Historic England Advice Note 12.

Cadw (2017) Heritage Impact Assessment in Wales.

Cadw, Countryside Council for Wales & ICOMOS (2007) Guide to Good Practice on Using the Register of Landscapes of Historic Interest in Wales in the Planning and Development Process Second Edition.

Cadw (2017) Setting of Historic Assets in Wales.

Welsh Government (2017) Technical Advice Note 24: The Historic Environment.

Department for Communities (2018) Guidance on Setting and the Historic Environment for Northern Ireland.

Department for Communities (2019) Guidance on making changes to Listed Buildings: Making a better application for listed building consent for Northern Ireland.

Department for Infrastructure (2019) Best Practice Guidance to PPS 23 ‘Assessing Enabling Development for the Conservation of Significant Places.

Department for Infrastructure (2019) Wind Energy Development in Northern Ireland Landscapes SPG.

Department of the Environment (2009) Best Practice Guidance to Planning Policy Statement 18 ‘Renewable Energy’.

Potential effects on physical offshore (water) environment which can affect local biodiversity and coastal land – e.g. water quality, waves and tides, scour effect (localised seabed erosion), sediment transport and suspended solids – these can affect marine ecology, archaeology, navigation channels marine vessels and coastal recreation activities.

Please see onshore wind energy section for potential issues relating to terrestrial hydrology, hydrogeology and water sources.

The following would be needed:

Prediction of physical effects as a result of construction and operation of required infrastructure including effects such as scouring.

Geotechnical investigations to understand the hazards in the area and the geology of the region.

Pre-construction baseline water quality sampling and analysis.

Environmental Management Plan (e.g. including use of silt traps, buffer zones from watercourses etc. and water quality and flow monitoring plans.) This should also include plans for surface water drainage as well as good practice measures.

Burying of cables to a necessary depth.

Using scour protection techniques around offshore structures to prevent scour effects or designing turbines to withstand scour, so scour protection is not required or is minimised.

Applicants should consult the statutory consultees on appropriate mitigation and monitoring and consult with the Crown Estate.

A Construction Method Statement should be produced based on the detailed design of the onshore elements and the approach to things like watercourse crossings.

Pollution Prevention and Emergency Incident Response Plan (PPEIRP) – Areas at risk of spillage, such as vehicle maintenance areas and hazardous substance stores will be carefully sited to minimise the risk of hazardous substances.

A Soil Management Plan – provides details of mitigation measures and best practice handling techniques to safeguard soil resources by ensuring their protection, conservation and appropriate reinstatement during the construction of the onshore works associated with the offshore wind.

Implement good pollution prevention practices based on Natural Resources Wales’ guidelines and CIRIA documents.

For EIA Development:

A chapter on hydrology, hydrogeology and water sources within an ES should be included.

There is no published guidelines or criteria for assessing and evaluating the effects of this topic in the context of an EIA. Professional judgement and a qualitative risk assessment methodology is used instead.

A detailed decommissioning document may be included as a standalone separate document.

It may be necessary to monitor water quality and flood risk post consent due to the potential impacts of the onshore infrastructure needed. However monitoring post consent is not usually needed.

Department for Energy Security and Net Zero (2023) Draft NPS for Renewable Energy.

ADAS (1993) The Design of Field Drainage Pipe Systems, Report No.345.

UK Government (2021) Understanding effective flood and coastal erosion risk governance in England and Wales.

Centre for Ecology and Hydrology (2006) Flood Estimation Handbook CD-ROM V2.0.

Welsh Government (2021) Technical Advice Note 15: Development, Flood Risk and Coastal Erosion.

CIRIA (2002) Control of Water Pollution from Construction Sites – Guide to Good Practice on Site.

The Water Framework Directive (2000/60/EC).

The Water Environment (Water Framework Directive) (England and Wales) Regulations 2017.

The Groundwater Directive (2006/118/EC, including amendments to Annex II detailed under Directive 2014/80/EU).

The Floods Directive (2007/60/EC).

Bathing Water Directive (rBWD) (2006/7/EC) (England and Wales).

The Environmental Permitting (England and Wales) Regulations 2016.

The Flood Risk Regulations 2009.

Flood and Water Management Act 2010.

The Water Resources Act 1991.

The Land Drainage Act 1991 and The Land Drainage Act 1994.

Environment Act 1995.

The Private Water Supplies (Wales) Regulations 2017.

Disruption to pipelines

Disruption to pipelines – e.g. oil and gas, international energy cables and telecoms, especially during construction and operation.

Impact on employment and expenditure in local economy

Impact on employment and expenditure in local economy i.e. impacts on commercial fisheries and fishing. Potential positive impact on spending in the local economy due to construction workers needing accommodation.

Long term positive impacts on employment by enabling local residents to access employment opportunities through operation and maintenance activities.

Impact on navigation and shipping

Impact on navigation and shipping. This includes potential for increasing vessel collision risk in all weather conditions, increased risk of anchor snagging due to deep sea cables etc.

Disruption to pipelines

Telecommunications Impact Assessment

Desk-based assessment on the types of utilities within the area and feasibility work to see if its viable to build in these areas.

Impact on employment and expenditure in local economy

Early consultation with the MMO, Defra and other representatives.

Surveys of effects on fishing activities

Surveys on the level of local employment and spending that could occur as a result of a long construction period. Stakeholder engagement is key at all stages in the project.

Impact on navigation and shipping

Navigational Risk Assessment to determine if there is a consenting risk of building the turbines in those areas.

All impacts

Consultation with affected stakeholders is key for this topic. This may require financial compensation to allow the development to be consented.

Safety zones that take into account effects on commercial fishing.

There should be safety zones on pipelines to avoid catastrophic effects.

Maximise use of local labour, services and supplies. This will result in a positive socio-economic impact.

Site configuration, lighting and marking of projects to take account of any requirements of the General Lighthouse Authority.

Cable burial should be considered to protect the cables.

Safety Zones of up to 500m should be applied during construction, maintenance and decommissioning phases.

All impacts

For EIA development:

A socio-economics chapter of the ES could be prepared if required. These are often included as standalone reports separate from the ES.

A Cable Specification and Installation Plan may also be required.

All impacts

A monitoring plan may be developed to make sure there is limited impacts on infrastructure and the positive impacts on the local economy / residents continues.

Welsh Government (2005) Technical Advice Note 8: Planning for Renewable Energy.

HM Treasury (2021) Build Back Better: our plan for growth.

Department for Business, Energy and Industrial Strategy et al (2020) The Ten Point Plan for a Green Industrial Revolution.

Department of Business, Energy and Industrial Strategy (2020) Energy White Paper.

HM Treasury (2020) National Infrastructure Strategy.

UK Government (2017) UK Industrial Strategy, White Paper.

Department for Business, Energy and Industrial Strategy (2019) Sector Deal.

Department for Energy Security and Net Zero (2023) Draft NPS for Renewable Energy.

HM Government (2011) UK Marine Policy Statement (MPS) .

Defra (2014) The East Inshore and East Offshore Marine Plans.

Impact on telecommunication cables, oil and gas pipelines and platforms or marine aggregate dredging

Impact on telecommunication cables, oil and gas pipelines and platforms or marine aggregate dredging etc. This could have major environmental impacts if not managed effectively, with oil spills being a high risk.

Impacts on aviation and radar

Impacts on aviation and radar.

All impacts

Assessment of the potential effects of the proposed development on existing infrastructure or activities (should be undertaken for the lifespan of the proposed wind farm).

Telecommunications Impact Assessment should be prepared.

Desk-based assessment on the types of utilities within the area and feasibility work to see if its viable to build in these areas.

All impacts

Mitigation measures should be agreed with all relevant parties such as financial compensation. Stakeholder engagement is key.

Safety Zones of up to 500m should be applied during construction, maintenance and decommissioning phases.

All impacts

For EIA development:

This topic is likely to be included as a standalone document or submitted as an additional document to the planning application.

An appendix for the Telecommunications Impact Assessment may also be prepared if required.

A Cable Specification and Installation Plan could be required.

All impacts

A monitoring plan may be developed to make sure there are limited impacts but it is likely no further monitoring will be considered.

Department for Energy Security and Net Zero (2023) Draft NPS for Renewable Energy.

Planning Act 2008

Marine Policy Statement, 2011.

The East Inshore and East Offshore Marine Plans (Defra 2014)

Offshore Installations (Offshore Safety Directive) (Safety Case etc.) Regulations 2015 and associated guidance document L154

Offshore Installations and Wells (Design and Construction etc.) Regulations 1996

Pipeline Safety Regulations 1996, in particular Regulations 5-17, 18-24 Schedules 2-5 and associated Guidance Document L82;

Provision and Use of Work Equipment Regulations 1998, in particular Regulations 4, 5 and 12;

Maritime and Coastal Agency (MCA) – Methodology for assessing the marine navigational safety & emergency response risks of offshore renewable energy installations (OREI), April 2021;

European Subsea Cables Association (ESCA) (2016). ESCA Guideline No.6 The Proximity of Offshore Renewable Energy Installations & Submarine Cable Infrastructure in UK Waters;

HM Government (2017). The Clean Growth Strategy Leading the way to a low carbon future.

Offshore Installations (prevention of Fire and Explosion, and Emergency Response) Regulations 1995) and associated Approved Codes of Practice (ACOP) and Guidance Document L65;

The Diving at Work Regulations 1997

Safety of Life at Sea (SOLAS) Chapter IX, ‘Management for the Safe Operation of Ships’ 1998. The ISM Code provides an international standard for the safe management and operation of ships and for pollution prevention.

Increase in vehicle movements and noise on local roads during construction and the potential for abnormal loads being transported through local roads.

Transport and Traffic Impact Assessment.

Prepare Traffic Management Plan (as appropriate) which should include measures for avoidance of HGV deliveries during peak construction periods etc.

Work together with other projects to ensure the number of abnormal loads and deliveries is minimised and the timings of deliveries are managed and coordinated to ensure that disruption to local residents and other highway users is minimised.

For EIA development:

An Access, Traffic and Transport chapter within the ES would be required. This would typically include a Transport assessment (TA) as an appendix.

Additional assessments required may include:
– Abnormal Load Transport Management Plan.
– Construction Traffic Management Plan.

No further monitoring will be needed for operation and maintenance.

During construction regular maintenance would be undertaken to keep the site access track drainage systems operational and ensure there are no run-off issues into the public road networks.

Adherence to the Construction Traffic Management or Abnormal Local Management Plans.

Institute of Environmental Assessment (1993) Guidelines for the Environmental Assessment of Road Traffic.

The Highways Agency (2006) Design Manual for Roads and Bridge.

Institution of Highways and Transportation (1994) Guidelines for Traffic Impact Assessment.

Welsh Government (2017) Transport Appraisal Guidance (WelTAG).

Strategic Traffic Management Plan (STMP).

Welsh Government (2020) Pulling Together, Best Practice for Transporting Abnormal Loads in Wales.