Version: August 2022
This latest version of our General pre-application and scoping advice for onshore wind farms replaces the previous version published in October 2020. Besides generally refreshing the text, the main changes are:
- The removal of the checklist table.
- The addition of several new sections, including on survey ‘shelf life’, section 36 variations, and repowering.
- An update to our turbine lighting advice (at Annex 1).
This guidance aims to help developers and consultants who are involved in preparing Environmental Impact Assessment reports (EIA reports) for onshore wind farm developments.
It presents our general pre-application and scoping advice, contains links to more detailed guidance, and outlines the type of survey and assessment work that developers may need to undertake to support a wind farm application.
We highlight that the approach to development should deliver overall positive effects for biodiversity.
Note that throughout this guidance we use “consenting authority” as shorthand to encompass both planning authorities and the Scottish Ministers.
We use the word “pre-application” to encompass the formal EIA scoping stage.
The service that NatureScot provides
We are committed to helping the Scottish Government and planning authorities to deliver a modern planning system – one that is fast and inclusive, delivers sustainable economic growth and benefits nature.
Our Service Statement and related guidance set out the level of engagement you can expect from us during the planning process. Our guidance on the service that developers and consultants can expect is particularly relevant and can be read alongside this pre-application and scoping guidance.
We will only consider objecting to a development proposal (or submitting a conditioned or holding objection) when the impacts on nature and landscapes raise issues of national interest. Our guidance on ‘Identifying Natural Heritage Issues of National Interest in Development Proposals’ provides the framework for deciding when we will object to proposals for development and land-use change. This guidance is of particular interest in relation to impacts wider than, or beyond, protected areas of national or international importance.
A ‘no comment’ response, or the lack of an objection by us, should not be interpreted as support for a proposal or an indication that there are no impacts on the natural heritage that need to be taken account of. We expect decision makers to consider all of our advice, including standing advice, in determining planning applications.
Our pre-application engagement with developers before they submit an application provides an opportunity to resolve potential problems early and help speed up decision-making. Our level of engagement and the scope and detail of our advice will be in proportion to the nature, scale and importance of the potential impacts a proposal might have on the natural heritage.
At the pre-application stage, our priority is to identify the potential impacts on nature and landscapes that could raise issues of national interest. The degree of national interest will determine our level of engagement in a proposal.
At application stage, we will only provide tailored advice for Planning Act cases where impacts closely approach or exceed levels that raise issues of national interest. We will provide case-specific advice on issues that are not of national interest for section 36 (Electricity Act) cases. This includes advice about impacts on:
- landscape and visual amenity;
- birds in the wider countryside;
- peatland and carbon-rich soil;
- protected species (although this is increasingly provided through our standing advice).
Initial contact with us should be through the Area Office relevant to the location of a development. In relation, please refer to the mapped coverage and contact information for our Area offices. Thereafter please direct all queries to the case officer assigned to your proposal. The case officer will co-ordinate the provision of advice.
You should allow sufficient time in your project plan to accommodate our advice. Our typical customer care timescale for responding to pre-application requests is within 20 working days but there can be delays in responding when other statutory consultations take priority.
Freedom of Information
Any information submitted to us during pre-application discussions may be subject to a request under the Environmental Information (Scotland) Regulations 2004. For this reason, although we are keen to receive information about the proposal at the pre-application stage, we cannot do so on the basis that we hold that information in confidence.
As a developer, you can take some steps to help us manage your information by separating out, and clearly marking, environmentally and commercially sensitive information. You can also provide us with an explanation of the harm that would occur if your information was released.
General advice to help inform the EIA
Our website includes onshore wind energy guidance and information to help ensure that you undertake a robust EIA.
Our guidance is subject to periodic review, so please ensure you are following the latest version on our website. The complete list of our standing advice and guidance helps provide easy reference to latest versions of documents.
Please consider the following general advice in addition to any case-specific pre-application advice we might provide.
Our guidance on siting and design describes how wind farms should be sited in landscapes best able to accommodate them and designed to minimise impacts.
Our guidance on visual representation helps developers produce visualisations which are easy to understand and which can be verified.
Paragraph 212 of Scottish Planning Policy states that development that affects a National Scenic Area (NSA) or National Park (NP) should only be permitted where:
- the objectives of the designation and the overall integrity of the area will not be compromised; or
- any significant adverse effects on the qualities for which the area has been designated are clearly outweighed by social, environmental or economic benefits of national importance.
Developers should refer to our policy and advice on NSAs. We are also developing guidance on how to assess effects on NSA Special Qualities and can provide a draft copy of that guidance by request. Our website also contains advice on National Parks.
Our advice and guidance on Wild Land Areas (WLAs) should be applied to proposals whose nature, siting, scale or design are likely to result in a significant effect on the qualities of a WLA.
Our website provides helpful general information on Local Landscape Areas (LLAs), but specific information and advice on LLAs will be available from planning authorities.
Turbine lighting is an emerging consideration and our advice on assessing its effects is contained in the annex to this guidance.
Terrestrial habitats and peat
We advise that habitat surveys should include:
- Phase 1 (or EUNIS) habitat survey.
- National Vegetation Classification (NVC) survey (of habitats listed on Annex 1 of the EC Habitats Directive and UK Biodiversity Action Plan (UKBAP) Priority Habitats), accompanied by supporting vegetation quadrat information. A useful comparison between these (and other) habitat classifications is available in JNCC’s interactive Spreadsheet of Habitat Correspondences.
- Records of any rare and scarce plant species.
We advise that habitat surveys should cover the entire development site. This will help inform redesign or micro-siting where necessary, and will also help identify potential areas for habitat restoration/enhancement. The habitat assessment needs to encompass all areas affected by the development, including for example areas indirectly affected by hydrological changes.
Access tracks are the elements that will result in the greatest land take, habitat fragmentation and, potentially, hydrological disruption. The EIA report should therefore provide rationale for their location and type (whether “floating” or “cut and fill”) and should describe track construction methods.
The Carbon and Peatland map 2016 is a high-level tool that provides context for more detailed peat survey work. The map is not a definitive account of where important carbon rich soils, deep peat and priority peatland habitat exist. Development proposals on peat, whether in the mapped area or not, will always require a site-specific and detailed peat and vegetation survey. This will confirm the quality and distribution of peatland across the site, including the extent to which nationally-important peatland will actually be affected by the development. Where the presence of peat may be a material issue for siting of infrastructure, peat survey is likely to be required in line with Scottish Government peatland survey guidance.
As noted in that peatland survey guidance, the results should inform:
- Site design and layout to minimise disruption to peatlands
- Peat and Habitat Management Plans
- Carbon savings & losses evaluation
- Drainage planning and hydrological assessment
- Peat landslide hazard and risk assessments
- Post-construction habitat management/site reinstatement and restoration.
Our guidance on carbon-rich soils, deep peat and priority peatland habitat in development management explains how we offer advice on these matters. The annex to that guidance provides a summary of how NatureScot and Scottish Environment Protection Agency (SEPA) roles differ regarding carbon-rich soils, peat and peatland. Our advice will focus on peatland habitat and we recommend early engagement with SEPA with regard to issues that are part of their remit.
In summary, we advise the following approach to development on peatlands:
- We encourage development to avoid carbon-rich soils, deep peat and priority peatland habitat and to minimise losses of the highest quality peatland habitat. Besides protecting nature, avoidance will help reduce carbon release and the technical challenges of managing peat.
- Where avoidance is not possible, mitigate any impacts by, for example: adopting alternative construction techniques (such as floating roads); carefully planning site drainage; and following good practice for handling, storing and reinstating peat materials.
- Restore and improve the condition of existing peatland habitat to compensate for unavoidable residual adverse effects. Measures may involve, for example, blocking drains/installing dams and reducing grazing and trampling pressures.
- Habitat enhancement should go beyond compensation; it should provide overall positive effects or net benefit for peatland interest.
We recommend that, as a minimum, all areas directly (e.g. watercourse crossings) or indirectly (e.g. sediment run off) affected by the development and appropriate buffers up and downstream should have a habitat survey. This should inform the likelihood of the presence of salmonids, eels, freshwater pearl mussel and other protected/Biodiversity Action Plan (BAP) species and so the need or otherwise for species-specific surveys.
Where there is connectivity to protected areas, e.g. river or loch Special Area of Conservation (SAC), then a higher level of targeted survey effort and assessment may be needed (e.g. to inform an appropriate assessment for a SAC).
Note that where there is suitable habitat for freshwater pearl mussel, and particularly where salmonids are present, we would expect survey following the method referenced in our standing guidance for freshwater pearl mussels. Geographical exceptions for this survey requirement would be the Borders, Lothian and some parts of Fife where freshwater pearl mussel are unlikely to be present. Advice on the need or otherwise for freshwater pearl mussel surveys in Fife should be sought from the NatureScot Area Office or the relevant case officer.
Marine Scotland Science (MSS) provides scoping and monitoring guidance for freshwater and diadromous fish (including salmon) which should be followed for proposed section 36 applications. MSS encourage developers of wind farms with a proposed capacity of 50MW or less to also consult their guidance, given that the potential impact pathways for freshwater and diadromous fish, and associated fisheries, are the same regardless of the proposed generating capacity.
Developers will also find it helpful to refer to SEPA’s guidance and information on wind farm development.
Our website provides a range of guidance about wind farm impacts on birds. This includes our guidance on bird survey.
We generally recommend the collection of a minimum of two complete years of bird survey data to allow for variation in bird use, unless it can be demonstrated that a shorter period of survey is sufficient. If you are proposing less than two years of bird survey, we advise you seek agreement from the relevant consenting authority, who may then consult with NatureScot where appropriate.
Our advice on turbine lighting and birds is contained in the annex to this pre-application guidance.
Our standing advice note on planning consultations and birds should further help applicants submit proposals that minimise impacts.
The presence (or potential presence) of other legally protected species also needs to be factored into the planning and design of wind farm proposals. Any impacts on protected species must be fully considered prior to the determination of the application, and if there is evidence to suggest that a protected species is present on site or may be affected by the proposed development, steps must be taken to establish this. Recent, site-specific surveys provide reassurance on presence or absence, and so underpin the required consideration. Our standing advice notes for protected species helps set out survey (and mitigation) requirements for a range of species, including:
- Freshwater pearl mussel
- Great crested newt
- Pine marten
- Red squirrel
- Water vole
The absence of existing records for a particular location does not necessarily mean that protected species are not present, so new species surveys should not be ruled out solely for this reason. It could just be because that location has not been adequately surveyed before. In addition, some species have been found in unexpected places, for example remnant freshwater pearl mussel populations above impassable fish obstacles.
Should surveys identify that a protected species could be affected by the development, then a Species Protection Plan will be required. The Species Protection Plan should include:
- measures proposed to minimise impacts on the species, including annotated maps and/or photographs showing the location of any measures proposed and how they relate to survey information and construction work;
- a summary of any residual impacts once the above measures are taken into account;
- details of any licensing requirements.
Where impacts on a protected species cannot be avoided, certain activities may only be undertaken with a licence from NatureScot. It is important that any licensing issues are considered as part of an application for planning permission or section 36 consent. Where licensing may be relevant, there will be a need for the consenting authority and developer to satisfy that the tests for that licence are likely to be met before the application is approved. If not, there may be an unnecessary delay to a development proceeding, or the applicant could risk being unable to make practical use of any permission/consent or could risk committing an offence. Our standing advice includes, advice on the likelihood (with reference to relevant ‘tests’) that a licence will be granted. Applicants should contact [email protected] regarding any licence application.
Note that pre-construction survey will usually be required for the species already considered at pre-application stage. Pre-construction surveys enable checks for new occupation, or changed distribution, further to the original survey, and so help ascertain whether protected species could be affected by the development.
Advice on the timing of pre-construction surveys is contained in our standing advice notes. In general, for those species that can be surveyed at any time of the year (e.g. badger, otter and wildcat), surveys should be completed as close to the construction period as possible, and no more than three months before the start of works. For species with restricted survey periods (e.g. bats, great-crested newt, pine marten, reptiles and water vole), pre-construction surveys should be completed as close to the start of works as possible, and always within the most recent survey period. This takes account, for example, of where you can only survey for the species in the summer and you plan to begin development in late winter; in which case the most recent pre-construction survey information you could possibly gather would be from the preceding summer survey period. Slight variations apply to beaver, where pre-construction survey is advised within two weeks of starting works; and to red squirrel, where pre-construction survey is advised as close to the construction period as possible, and no more than 3 months before the start of works, but any dreys affected should be re-surveyed every 3 weeks to confirm status during the breeding season.
As noted in our standing advice note for bats, an activity survey to assess the risk of collisions should follow the methods described in our guidance on bats and onshore wind turbines - survey, assessment and mitigation.
Our advice on turbine lighting and bats is contained in the annex to this pre-application guidance.
Survey 'shelf life'
Survey ‘shelf life’ relates to how long survey results would normally remain valid before repeat survey is required. Our standing advice notes for protected species include advice on survey shelf life.
For those species that can be surveyed at any time of the year (e.g. badger, beaver, otter, red squirrel and wildcat) our advice is:
- Pre-application surveys normally remain valid for two years, and should be repeated if the application is delayed beyond that. In certain cases, it may be clearly evident that there has been no substantive change in number, distribution or activity since the original survey was undertaken. An initial walkover survey may help confirm that existing information is reliable, or identify where new survey work is required.
For those species with restricted survey periods (bats, freshwater pearl mussels, great-crested newt, pine marten, reptiles and water vole) our advice is:
- Pre-application surveys normally remain valid for two more survey periods, and should be repeated if the application is going to be delayed beyond the start of a third survey period, unless it is clearly evident that there has been no substantive change in number, distribution or activity since the original survey was undertaken.
If substantive land use, guidance, habitat or population changes have occurred since your survey, we recommend that you seek advice from the relevant consenting authority (who may then consult with NatureScot where appropriate) prior to submitting your application. This will help to ensure the surveys remain an adequate basis for the impacts to be fully considered prior to determination.
As noted in our bird survey guidance, to help ensure that bird data are reliable and not too dated we advise that it should have been collected within the last five years, or within three years if the populations of key species are believed to be changing rapidly. Please seek advice from the relevant consenting authority (who may then consult with NatureScot where appropriate) if populations of key bird species are suspected to be changing rapidly or if there have been substantial habitat changes between the survey and application submission e.g. the baseline has changed say from large area of mature plantation to clear-felled open ground.
Applications to vary section 36 consents
We will normally accept greater reliance on existing ecological survey information for applications to vary section 36 consents, as discussed in our staff guidance on dealing with s36 variation applications.
Applications for repowering
Repowering is in its infancy and we are still learning about the assessment required. Some aspects of survey and assessment will need to be different because of the presence of existing turbines. Assessment is likely to benefit from a tailored site-specific approach.
Repowering and birds
Please engage early with us before commissioning bird surveys in particular. In some circumstances, it is possible that new bird survey may be unnecessary, for example, if contextual data clearly suggests there is little bird interest present on the site, or if good, recent, post construction monitoring data is available. Typically, however, we expect that there should be one year of new distribution and abundance bird surveys, following our bird survey guidance. If the proposal includes an extension beyond the footprint of the existing wind farm, then two years of full bird survey work is likely to be required in those areas, following the standard approach for any wind farm extension.
Compared to a new wind farm development, a greater qualitative element (with reasoned judgements) may be required for the bird assessment. The assessment could potentially draw upon various sources of information, including:
- original survey data and assessment;
- relevant additional survey information;
- post-construction monitoring data, e.g. records of carcass searches/collisions recorded;
- data held by the Scottish Raptor Study Group, RSPB etc.; and
- up-to-date information about conservation status, legal status, disturbance distances and collision risk avoidance rates for any sensitive species present.
Collision risk modelling calculations are meant to be based on flight activity when there are no turbines present. However, assessments for repowering are likely to take place while the existing wind farm is still in situ. The risk of collision with moving wind turbine blades is related to the amount of flight activity over the proposed development site, the species’ behaviour, and the ability of birds to detect and manoeuvre around rotating blades. The standard method of quantifying potential bird collisions with onshore turbines takes account of an ‘avoidance rate’ which is applied to account for behavioural adaptation of birds to the presence of turbines. However, such avoidance behaviour (causing changes in bird flight activity/distribution) will already be happening on a site where the wind farm is in place. It is not valid, therefore, to undertake collision risk modelling as set out in our guidance based on vantage point observations when there are turbines present. The results of such calculations will not be meaningful.
A better approach to re-evaluating collision risk for repowering would be to overlay the original vantage point data onto the new turbine layout, for which turbines are likely to have different locations and potentially different dimensions. Any extensions to the wind farm which occupy new ground will probably need new vantage point survey work, unless previous vantage point observations cover the new area satisfactorily.
Also, while not valid as a basis for collision risk modelling, in some cases new vantage point surveys could still be useful to inform a general understanding of flight activity (e.g. assessing flight corridors between roosting and feeding areas).
However, we recommend you agree the validity of any approach with the relevant consenting authority at the pre-application stage, in consultation with NatureScot where appropriate.
Repowering and other ecological survey
You should undertake new surveys covering species other than birds, including survey of freshwater interests, bat roosts and bat activity, but if relevant post-construction monitoring data of sufficient quality exists then these may not be necessary.
New habitat survey is likely to be required, unless there is sufficient evidence indicating that habitats are unchanged since the original survey, or the affected habitats are of low importance, such as intensively managed farmland.
Original peat survey information may still be relevant where conditions have not changed, but more survey may be necessary to comply with the latest peat survey guidance and in areas not previously covered, where new infrastructure is now proposed.
Repowering and habitat management
The success of habitat management associated with the original scheme should be reviewed and the repowering proposal should endeavour to avoid undoing previous restoration or enhancement work where possible, and any undoing of previous habitat management compensated for. New habitat management proposals should build on existing management, with a focus on ground not likely to be suitable for future infrastructure, e.g. constrained peatland areas or areas of low wind speed.
Repowering and visual representation
Paragraph 220 of our visualisation guidance offers brief advice on visualisations specifically for repowering schemes. However, as an update to the position set out in that part of the guidance, we advise that visuals should be compiled largely as for any new application, i.e. as follows:
- In terms of the ‘baseline panorama and matching wireline’, the baseline panorama is an illustration of the current landscape (not including the proposal) and should show the wider landscape and visual context. This should include the existing wind farm (to be repowered), i.e. do not remove the existing turbines as para 220 of our 2017 visualisation guidance currently states.
- As per the standard visualisation package, the matching wireline within the ‘baseline panorama and wireline’ should show the wind farm proposal and all other wind farms included in the cumulative assessment. This should include turbines at different stages in the planning process i.e. existing, consented, proposed – these shown in different colours to make it clear what the baseline is (existing and approved) and what is proposed. We advise that this matching wireline should also include the existing wind farm (to be repowered), but it will be particularly important to clearly distinguish (through use of colour) the existing turbines that will be removed for repowering.
- The single page ‘wireline’ should show the repowered proposal with numbered turbines, but should not show the existing wind farm turbines (to be repowered). This wireline will be valuable in allowing the assessor to compare the position and scale of the turbines to the existing view of a landscape.
- The ‘photomontage’ visual should show the repowered proposal ‘photomontaged in’ and the existing turbines (to be repowered) removed.
In summary, we advise that the ‘baseline panorama and wireline’ visuals should show the existing wind farm turbines (to be repowered), but that these turbines should not be included in the single page wireline or the final photomontage visual. This approach follows the ‘standard’ visualisation advice as far as is reasonable.
Species that may not require surveys
There are some protected species (e.g. moths and other invertebrates, and amphibians) that, with standard mitigation, are unlikely to experience any significant environmental effects. Such species will not normally require surveys to inform the EIA, unless they are European Protected Species (EPS) or qualifying features of protected areas. Instead, we advise that you should normally be able to apply mitigation during construction to minimise impacts and avoid committing an offence. Where these species are likely to be present, standard mitigation should be outlined in the application or EIA report. You should however provide clear reasoning for scoping out species surveys, either in the scoping report submitted to the relevant consenting authority or in the EIA report.
Our website provides an A-Z guide on which species are legally protected.
Habitat Management Plans
Survey results should be used to inform the design and layout process, so that the development avoids fragile and priority habitats and other sensitive areas e.g. blanket bog and peat. Where this is not possible, suitable restoration and/or compensation measures should be presented in the EIA report in the form of a draft Habitat Management Plan (HMP). HMPs should follow our guidance on What to consider and include in Habitat Management Plans. The HMP should also consider how to enhance the natural heritage interest of the area.
Access and recreation
Consideration should be given to the existing and potential use of the area for recreation by the general public, with reference to Scottish access rights under the Land Reform (Scotland) Act 2003 and rights of way. Planning Authorities including National Park Authorities have a duty to uphold access rights within their areas. These authorities have a lead role in advising on access management within the development site, including the effects of the development on existing access and opportunities for improved access provision. We recommend that you engage with Planning Authorities in the preparation of any access management plan, if required. This should identify the current recreational activities in the area and any positive or negative impacts that may occur as a consequence of the development during both construction and operation. We would wish to be involved at an early stage where impacts on nationally important recreation interests are identified.
Consideration should be given to the design of any new infrastructure such as tracks and signs to improve access provision and experience. When operational, the design should also ensure as much continued recreational use of the site as possible and minimise the visual impact from new and existing paths and tracks.
Access should be managed actively during the construction phase, with restrictions kept to the minimum area and a duration that is practical and reasonable, and adapted as the site develops to focus on where actual risks are present. This approach is likely to encourage greater compliance by the public and will therefore be more effective in meeting safety needs, including obligations under the Construction (Design & Management) Regulations. Further information about access provision and management can be found in the guidance on good practice during wind farm construction.
If wild deer use the development site, you should assess the implications of the development on deer and the indirect impacts on other interests (e.g. habitats, neighbours, roads, etc.). You should present the assessment as part of your EIA report, even if you conclude that impacts are unlikely. The assessment may indicate the need for management to avoid adverse impacts. If so, we advise the need for a deer management statement, either as part of a Habitat Management Plan or as a stand-alone document. For some sites, the modification of an existing Deer Management Plan covering a wider area may be more appropriate. We do not expect developers to exert control over land that they have no rights over. However, we encourage a collaborative approach with neighbouring landowners and managers to avoid adverse impacts on the interests of all parties. A deer management statement may be included amongst the EIA report’s submitted mitigation measures, or produced to comply with a planning condition. See our guidance on what to consider and include in deer assessments and management at development sites.
Trees and forestry
If tree felling/woodland clearance will be required as part of the proposed development, we recommend that you contact Scottish Forestry at as early a stage as possible to discuss the Control of Woodland Removal Policy and the implications it may have on the development. You should also refer to the SEPA, NatureScot and Scottish Forestry joint guidance on Use of trees cleared to facilitate development on afforested land.
Decommissioning and restoration
We advise that you consider decommissioning and post-operational restoration during the initial design phase of the development, to help ensure that decommissioning of infrastructure and the restoration of habitats and ecosystems is achievable and practical once the development has ceased operating. Our guidance on decommissioning recommends that it is good practice to include an outline Decommissioning and Restoration Plan (DRP) in the EIA report or other documents supporting a planning application. Prior to consent it will not be possible to plan for decommissioning in detail, so the outline DRP should be brief but provide an appropriate level of detail about how the site infrastructure may be removed and how the site is intended to be restored. We recommend revision of the DRP 3-5 years prior to the year of decommissioning, to provide full details of decommissioning and restoration for approval by the planning authority. This is because environmental conditions, laws and techniques may change during the operational lifetime of a scheme. Further survey work may be required to inform the final decommissioning plan. As a guide, we suggest that the final decommissioning plan should contain a similar level of detail to a Construction and Environmental Management Plan (CEMP).
Restoration should include the removal of new tracks and restoration of existing tracks to their pre-wind farm width during the decommissioning process, to return the site to the same or better state than pre-construction. However, we recognise that there could be situations where retention of some tracks might be beneficial (e.g. for access and recreation where they provide links to important routes, where removal may cause damage to important natural heritage interests, etc.). The pros and cons of track removal/retention for each individual site can be considered more fully in the 3-5 years prior to a decision being taken on decommissioning. This should be done in consultation with the planning authority (and NatureScot and SEPA, as appropriate).
If you have confirmed details of all or part of the grid connection at the time of EIA report submission, these details should be presented in the EIA report along with assessments of the impacts of the grid connection on the natural heritage, in particular with respect to any protected areas affected.
Showing that you have considered consultees' advice
To help demonstrate that you have taken account of scoping and other pre-application advice, it is useful to provide a table summarising the specific key points raised at scoping/during pre-application, alongside information on how you have addressed them.
Presentation of assessment information
Where you have carried out an assessment, it can be useful to present that information in the EIA report, even if the conclusion is that there will not be significant effects. This helps demonstrate that all relevant interests are adequately considered. However, this does not mean that every issue needs covered in detail in the EIA report.
A table of issues/interests initially considered but then scoped out of further assessment should be provided in an annex, along with a short justification for each issue/interest.
Structuring the ecological chapters
We recommend that you split ecological chapters into sub-topics, e.g. protected areas, species (birds, bats, otter, etc.), habitats (terrestrial, freshwater), etc.
Chapters should present information on which activities associated with the construction, operation and decommissioning are likely to have direct and indirect (including cumulative) significant environmental effects on the relevant natural heritage receptors, e.g. habitat or protected species.
There should also be clear information on any mitigation, compensation and enhancement
A schedule of environmental mitigation should be provided for developments with impacts on multiple natural heritage interests. The schedule should compile all the environmental mitigation/enhancement measures into one list/table, for ease of reference.
Including environmentally sensitive information
Sensitive species information should be presented in a confidential annex with restricted circulation, for example, please see our guidance on environmentally sensitive bird information.
Full survey details including raw data, workings for calculations and results should be presented in the EIA report. Technical appendices should be used for this where appropriate.
Ease of use
For ease of use, we advise that text chapters and appendices of EIA reports are presented on A4 paper (rather than A3).
We recommend provision of landscape figures in a ring binder (rather than being spiral or otherwise bound), for ease of use during site visits.
All figures (including maps, photographs and other visualisations) should be clear and of good quality, of an appropriate scale, with distinct legends and scale bar (where appropriate).
All applications which require an EIA should include landscape and visual impact assessment visualisations which comply with the standards set out in our visual representation guidance.
All ecological figures should show the application boundary, proposed turbines, tracks and other infrastructure locations, as well as the relevant ecological information/survey results (e.g. otter couches, pine marten scats, etc.).
Figures should also be used to show the area surveyed/transects/quadrat locations etc., for each survey undertaken. It may be possible to include this information on the results map, where doing so will not obscure the results. For whole development site surveys, it may be appropriate to refer to the boundary shown on the site layout map, rather than provide multiple figures showing the same thing.
Presenting bird survey information
For any vantage point surveys, a view-shed map should be presented showing numbered vantage point locations, the 180-degree arc of view/visibility from each vantage point, and areas of overlap. The arc of views should be coloured in such a way that they are distinct from each other, and any overlaps are obvious (without obscuring the underlying topography and site detail).
Flight maps should be presented with labelled or otherwise defined (by colour and/or line type) flight lines, showing the flights banded into below, at and above collision risk height, referenced to a table of flight survey data. Depending on the amount of flight activity, it may be beneficial to present figures by species and/or breeding season (e.g. non-breeding season greylag geese flights on one figure, breeding greylag geese flights on another figure, breeding golden eagle flights on another figure, etc.). All figures should show the application boundary, turbine locations, proposed tracks and other infrastructure.
Nest/territory locations for target species should be included but comply with our guidance on environmentally sensitive bird information.
All raw bird survey data must be included in an annex and include the dates, times and weather conditions of surveys.
Describing survey methodologies
Full survey methodologies need not be presented in the EIA report where they have followed recognised methodologies that are publicly available (e.g. via the NatureScot website). A figure along with an outline description including dates, weather conditions (where relevant to the survey type) and how the survey was undertaken, along with a link to the methodology is sufficient. (E.g. “A habitat suitability survey was undertaken on 12 July 2020 along the watercourses shown in figure X. Watercourses A and B were identified as having potential freshwater pearl mussel habitat, so were surveyed for freshwater pearl mussel on 13 July 2020 following NatureScot’s survey methodology. The weather when the surveys were carried out was dry, with little rain in the preceding week. Consequently the water was considered to be at normal level.”)
Departing from typical survey methodologies
Where proposed survey methods or other work deviates from the published guidance, we recommend that you agree this with the consenting authority in advance of the survey (who may then consult with NatureScot where appropriate). A full description of the methodology used should be provided in the EIA report, along with an explanation of why any deviations are considered appropriate. Technical appendices should be used for this where appropriate.
Providing us with copies of the EIA report
Please speak to the relevant case officer about providing a hard copy and/or digital copy of the EIA report to us. We will often now access EIA report information through planning portals, or the ECU website, but we do typically require a hard copy of LVIA visual material. Please also remember to send us any confidential annexes. If sending us electronic information, the digital file sizes should be relatively small (<10MB per pdf) to allow us to manage these easily on our file system, although slightly larger file sizes can sometimes be accommodated. Electronic file names should clearly indicate the content of the document or figure (e.g. “Little Loch wind farm - LVIA Figure 6.18a - VP8 Bonar Bridge”).
Annex 1 - NatureScot advice on the scope of assessment for turbine lighting
Unless otherwise agreed with the Civil Aviation Authority (CAA), turbines of 150m or taller require visible lighting (see CAA’s policy and guidance on wind farms). Turbines less than 150m may also require visible lighting depending on location and proximity to both civil and military aviation interests.
Turbine lighting could result in significant landscape and visual effects in some locations. These effects are likely to be more significant in areas with less artificial lighting, including remoter rural locations, Wild Land Areas and dark sky sites where the absence of artificial lighting contributes to the feeling of remoteness and the direct appreciation of the night sky.
Scottish Government has established a working group of key stakeholders (including NatureScot) to consider the growing subject of turbine lighting, and to explore the evidence base around the environmental impacts of turbine lighting. Our advice here aims to help with the assessment of lighting impacts in the interim and will be informed by output from the working group.
Landscape and visual impact assessment
We have provide some brief advice on turbine lighting in our siting and design guidance (paras 2.11-2.13) and in our visual representation guidance (paras 174-177).
In addition, we advise that landscape and visual impact assessment of turbine lighting should include:
- The positions and intensity of lighting proposed. If only certain turbines will be lit, for example due to a mix of turbine heights or an agreed reduced lighting scheme, a plan should highlight which are the lit turbines. All the turbines in such a plan should be numbered.
- A Zone of Theoretical Visibility (ZTV) map which shows the areas from which the nacelle and tower lights are theoretically visible.
- Summary information on how many nacelle lights and tower lights will be visible from each viewpoint.
- Annotation of the positions of turbine lighting (including intermediate tower lights) on all wirelines from each viewpoint.
- Night-time visualisations from a proportionate number of representative viewpoints (we suggest two or three), selected on sensitivity or regular usage during low-light conditions and to be agreed with the Planning Authority (and NatureScot as appropriate). However, we acknowledge that it can be difficult to illustrate turbine lighting well in visualisations, as discussed in our visual representation of wind farms guidance referenced above.
- Assessment based on fieldwork for all viewpoints with potential visibility of lighting where effects may be significant. In a worst-case scenario, this may involve all viewpoints but professional judgement should be applied to ensure the assessment remains focused on likely significant effects (in accordance with Guidelines for Landscape and Visual Impact Assessment).
- Assessment of effects on landscape character, in particular where qualities of wildness, remoteness and lack of man-made elements are features of that landscape.
We advise further that:
- Turbine lighting would be an integral part of the wind turbine and will contribute to the magnitude of change introduced. As such, we recommend you consider assessment of the effects of lighting throughout the LVIA rather than producing the assessment as a separate section within the chapter. This will allow for a fully informed assessment of the impacts of the wind turbines (both day and night, individual and cumulative) on landscape character and visual amenity. A separate summary of the effects of turbine lights could be included for ease of reference.
- The assessment should take into account the baseline darkness/artificial lighting characteristics and people’s likely use of different areas during darkness and low light (dusk/dawn) conditions.
- The ZTV map, and an understanding of the nature of the likely effects, should inform the extent of the lighting assessment study area for the LVIA.
- In some cases, there may be the need to select some of the LVIA assessment viewpoints based on the turbine lighting impacts, as opposed to the day-time visual effects. Edge of settlement locations are likely to be better lighting assessment viewpoints, compared with locations within towns/villages (i.e. given the influence of existing street lighting, etc.).
- There may be health and safety concerns over taking dusk photography from remote viewpoints. We generally advise against alternative use of manipulated daytime photography in these situations due to the risk of misrepresenting the baseline (photographs should capture the baseline situation, i.e. other lights in the view). We would encourage discussion of this situation with the determining authority (and NatureScot where appropriate); in some cases a more accessible proxy viewpoint may be possible, for example.
- The scope and content of the assessment should be agreed early on with the relevant consenting authority. Samples of baseline photography can be useful to inform this stage.
We welcome the efforts being made by developers to explore a range of mitigation options to help to avoid or reduce lighting-related impacts. We support a proportionate approach to this issue so that the level of mitigation required is appropriate to the significance of the lighting-related impacts.
- We advise that you should seek to agree any bespoke lighting mitigation (e.g. a reduced lighting scheme) with CAA in advance of the application, and that if agreement is not in place, you base the assessment on requirements described in the current legislation.
- Current CAA policy guidance provides for a reduction in lighting intensity to 10% (e.g. from 2000 candela to 200 candela) if the horizontal meteorological visibility in all directions from every wind turbine is more than 5 km. Given the scenario where there may be good visibility in one direction, but 2000 cd lighting may still be activated due to poor visibility in another direction, we recommend that 2000 cd should be looked upon as the worst case, although the assessment can clarify the likely frequency and duration of dimming to 200 cd. Whilst photomontages should portray the worst case, additional photomontages illustrating the 200 cd lights would also be helpful where they are likely to predominate.
- Directional intensity mitigation can also be embedded within the design of the lights. This allows for reduction in downwards lighting impacts at elevations less than the horizontal plane. Reduced lighting intensity at lower elevation angles can be taken into account when determining the worst-case assessment from particular viewpoints.
Impacts of lighting on birds
The effect of wind turbine lighting on birds is not well understood, although studies at communication towers and other structures show that lighting can attract birds and in some circumstances result in significant collision mortality.
It is reasonable to exclude consideration of the impact of turbine lighting on birds in most circumstances. There are a few limited situations that give rise to a greater collision risk and would merit some consideration. These are where turbines are proposed in the following locations:
- Within or adjacent to breeding colonies of the three nocturnal burrow nesting seabird species, i.e. Manx shearwater, European storm petrel and Leach’s storm petrel. We can advise on suitable methodology to assess collision risk for these species.
- On or adjacent to protected areas that host large concentrations of wintering waterbirds.
- Within migratory corridors or bottlenecks for nocturnally migrating passerines. In Scotland, most passerine migration is on a broad front, though some geographical features such as river corridors may concentrate migration along a narrow front. Such information may come from local bird recorders and/or conservation organisations.
Quantifying the effects of turbine lighting in these exceptional circumstances can be done but may be technology challenging. Methods include use of radar, acoustic monitoring or ceiliometry (use of powerful lights to illuminate the night sky to detect flying birds). Given the methodological challenges, a precautionary approach to wind farm siting and/or the adoption of mitigation is likely to be helpful in addressing any concerns in these situations.
Impacts of lighting on bats
It is difficult to quantify the degree to which turbine lighting might increase bat collision risk. Some research has suggested that bat foraging activity is more likely to increase close to white, but not red light. Another study at a major European migratory corridor suggested an attraction of migratory bats to red light, this attraction being unrelated to any increase in foraging. Overall however, given difficulty in quantifying impacts, and the lack of evidence for any likely significant effects in Scotland, we do not advise that developers need to carry out any additional survey or assessment to determine the impacts of turbine lighting on bats.