Crystal Rig Substation Extension

Environmental Report_Technical Appendices

Technical Appendices 1.0 Planning Permission & Drawings 2.0 Extract of Environmental Report 2013 3.0 Landscape & Visual 4.0 Ecology 5.0 Cultural Heritage 6.0 Hydrology 7.0 Draft Schedule of Mitigation Measures

Technical Appendices Proposed Crystal Rig Substation Extension

March 2017

T e c h n i c a l A p p e n d i x 1 . 0 : P l a n n i n g P e r m i s s i o n & D r a w i n g s 3 East Lothian Council Application No: 13/00756/PM Dwg No Rev No Date Rec. 18SH-2-4100-DA-IECEC-0010 Location Plan 0G 19/9/13 18SH-2-4100-DA-IECEC-0011 Block Plan 0H 19/9/13 18SH-2-4100-DA-IECEC-0012 Elevations 0F 19/9/13 Dwg 001 (Extract IEC Technical Note)

Construction Access/ Egress Route 21/11/13

Scottish Borders Council Application No: 13/01084/FUL Dwg No Rev No Date Rec. 18SH-2-4100-DA-IECEC-0010 Location Plan 0G 19/9/13 18SH-2-4100-DA-IECEC-0011 Block Plan 0H 19/9/13

T e c h n i c a l A p p e n d i x 2 . 0 : E n v i r o n m e n t a l R e p o r t E x t r a c t 2 0 1 3 Crystal Rig Substation Extension_Environmental Report (MWH, 2013)

Chapter 12 (p131)

“Summary of Effects and Mitigation

Landscape and Visual

The LVIA assessment demonstrates that minimal effects will arise as a result of the proposed development. This is mainly due to the low height of the proposed substation extension and the placement within the landscape including the creation of an earthen mound around the western side. As a result it is considered that the proposed development would ‘fit’ within the landscape context and have no unacceptable effects on the landscape and visual resource.

The proposed development has been mitigated by building the proposed substation into the hillside and creating a large earthwork bund around it. This will effectively screen the substation extension from views looking eastwards to the proposed development. These earthworks will, as much as possible, use the existing soil on site, minimising the movement of earth from or to the site. Planting proposals will also be produced for the earthwork bunds to illustrate how they will be reseeded with grassland and planted with areas of Juniper and Gorse, in line with advice from the ELC Biodiversity Officer.

Ecology

The ecological assessment does not reveal any evidence of the presence of protected species nor notable plant nor habitat present within the area. There are considered to be no significant ecological constraints to proposed construction works.

However, a number of mitigation measures are proposed including:

• Pollution prevention measures should be implemented during earthworks in order to protect the surrounding marshy grassland habitat to include silt interception traps and/or mobile filter trapping units.

• Restoration should include use of excavated peat/soils and translocated vegetation turfs for site road verges and batters. The topsoil and subsoil should be separated during storage and, when used during restoration, used just underneath the vegetation turfs.

During the bird-breeding season (April to July inclusive) it is likely that common ground-nesting birds would be nesting within the rough dry heath/semi-improved acid grassland and marshy grassland. Therefore:

• Vegetation clearance, soil stripping and earthworks should be undertaken outside of the main breeding bird season, i.e. during August to March inclusive.

• If earthworks are to be undertaken within the bird breeding season (April-July inclusive), a pre-construction bird survey would be required (prior to earthworks commencing) in order to ensure that any active nest sites are identified and protected from disturbance and damage and to help ensure that the works proceed lawfully (i.e. in compliance with the Wildlife & Countryside Act 1981 as amended).

Archaeology and Cultural Heritage The archaeological and cultural heritage assessment has identified three assets of either local or lesser cultural heritage importance interest within an Inner Study Area, namely; an area of drainage ditches; a former location of a field bank and the remains of a trackway.

The area of drainage ditches and the field bank have been effectively destroyed, and therefore no mitigation is proposed. A potential impact upon the track way was predicted due to construction activities. Temporary fencing off or demarcation of this site would mitigate this potential impact. No residual direct impacts upon recorded cultural heritage assets are therefore predicted as a result of the proposed development.

One indirect (operational) impact of minor significance is predicted for the site of Boonslie, enclosures and farmsteads (MEL 1682), a site considered by ELC to be of schedulable quality. No mitigation measures are proposed in relation to the predicted indirect impact.

The potential for the proposed development area to contain previously unrecorded remains of archaeological significance is considered to be low.

Written guidelines would be issued for use by all construction contractors, outlining the need to avoid causing unnecessary damage to known sites. The documentation would detail contact arrangements for professional archaeological support as well as the legal responsibilities placed upon those who disturb artefacts or human remains.

Any archaeological mitigation works requested by East Lothian Council would be included in a Written Scheme of Investigation (WSI) produced for approval prior to commencement of construction works.

Provision would be made for the excavation and recording of any archaeological remains identified as a result of any mitigation works that could not be preserved in situ. This would include written reports on the findings of the archaeological work conducted, with post-excavation analyses, publication and archiving, where appropriate.

Hydrology

The Hydrology Assessment identified that the main effects likely to occur would be during construction of the substation extension; with a risk of increased surface water runoff and watercourse contamination by sediments or machinery pollutants, and groundwater contamination by long term seepage.

Appropriate SUDS techniques should be implemented to reduce the rate of surface runoff and treat surface water discharging into downstream watercourses. In addition, pollution control measures should be implemented to mitigate surface water and ground water contamination by machinery pollutants.

Flood Risk The flood risk assessment has been prepared to determine the potential effects of the proposed substation extension on flood risk and to suggest measures to mitigate risk. All sources of flooding were considered in the assessment.

The SEPA indicative flood map suggested that the proposal site is outside the flood extent and at low risk from fluvial flooding. Earlier studies suggest that if flows were to overtop the channel, they are predicted as flowing generally west to east, avoiding the site.

Runoff from adjacent marshland will be intercepted by extending an existing swale and controlling the runoff prior to discharging into any watercourse. A filter drain will be employed to manage flows generated by the new embankment.

The proposed works will involve an increase of approximately 0.1 ha of impermeable hardstanding (7.5 % of the total site area of 1.3 ha). The existing system is expected to manage the relatively small increase in runoff.

As the site is infrequently manned and no buildings are proposed as part of the works, flood risk to people and property is expected to be low.

As ground lowering has not been proposed, exposure of groundwater will be limited; therefore risk of flooding from this source is expected to be low.

The proposed extension to the substation is therefore considered to be at relatively low risk of flooding and is unlikely to increase flood risk elsewhere.

Drainage Strategy

The drainage strategy describes how runoff, that has been generated as a result of the proposed works will be dealt with during construction, operation and decommissioning.

Surface water from adjacent moorland will be intercepted means of a swale/ cut-off ditch. The swale will divert and convey flows from the adjacent moorland around the site and discharge via a new culvert and the existing northern culvert; onto marshy grassland.

An existing filter trench will be extended and will intercept any flows from the embankment/bund; preventing runoff from entering the site. Surface water will be discharged via the existing southern and northern culverts. The existing northern culvert is currently at capacity and will be replaced by a larger pipe under the separate NnG onshore works.

There will be a minor increase in impermeable surface owing to small sections of the internal access road and concrete pad footings; approximately 7.5 % of the proposed 1.3 ha extension will be converted to impermeable surface.

Runoff generated by the proposed development will either divert into the filter trench or be stored in the gravel sub-base of the compound and then, under gravity, will drain freely towards the existing substation site, where it will enter the existing surface water system of pipes and catch pits. The gravel base and catch pit will provide some level of attenuation. Runoff will then be discharged via a culvert towards the middle of the site onto marshy grassland located to the east of the access road.

Discharge from on-site surface water should be limited to the greenfield runoff rate; to be agreed with relevant stakeholders.

All outfalls will discharge runoff into the area immediately east of the access road. Due to the saturated conditions here, runoff will flow overland and into the headwater tributary of the Tay Burn.

The proposed works have the potential to create high volumes of contaminated surface water runoff. A number of mitigation measures and good practice guidelines have been highlighted for works during the construction phase (see Chapter 12).

It is expected that the decommissioning stage will return surface runoff conditions to, as close as possible to, natural conditions.

Traffic and Transport

The Falling Weight Deflectometer (FWD) analysis has indicated the majority of the length of carriageway surveyed is substantially lower in values for stiffness in contrast to the comparison sites. It is also evident that the surface course of the pavement is in very poor condition and shows substantial deterioration of the surfacing has occurred. An inspection of the site and surface defects indicate that could be due to heavy traffic loading. In some locations there is also evidence of edge cracking which may be due to poor support at the edge of the carriageway.

The areas of deterioration within the bituminous surfacing will require maintenance either before or during movement of the heavy loads. The carriageway condition will further degrade as additional site loadings are imposed on it. It is also recommended that the pavement is monitored during any future construction phases and provision should be made for undertaking any emergency repairs.

Further intrusive investigation in the form of pavement rotary cores and dynamic cone penetrometer testing would be required to enhance the interpretation of these results and provide an understanding of the structural integrity, material make up and bearing capacity of the existing pavement” (MWH, 2013, p131).

T e c h n i c a l A p p e n d i x 3 . 0 : L a n d s c a p e & V i s u a l

1.LVIA Methodology

Guidelines for Landscape and Visual Assessment Good practice described in the “Guidelines for Landscape and Visual Impact Assessment” as summarised below, is followed “to identify and assess the significance of the effects of change resulting from development on both the landscape as an environmental resource in its own right and on peoples views and visual amenity” (LI, IEMA, 2013). The first stage in undertaking a Landscape and Visual Impact Assessment (LVIA) is to establish the landscape and visual conditions. § “For the landscape baseline, the aim is to provide an understanding of the landscape

in the area that may be affected- its constituent elements, its character and the way this varies spatially, its geographic extent, its history (which may require its own specialist study), its condition, the way the landscape is experienced, and the value attached to it.

§ For the visual baseline, the aim is to establish the area in which the development may be visible, the different groups of people who may experience views of the development, the places where they will be affected and the nature of the views and visual amenity at those points.” (para 3.15, p32)

Establishment of baseline conditions and the key relevant landscape and visual aspects of the proposed development, allows the likely significant effects to be predicted. “LVIA, in common with other topics in EIA, tends to rely on linking judgements about the sensitivity of the receptor and about the magnitude of the effects to arrive at conclusions about the significance of the effects. These terms are effectively a shorthand way of describing the wider array of factors that underlie the nature of the receptor likely to be affected (sensitivity) and the nature of the effect likely to occur (magnitude)”(para 3.24, p.37). In accordance with the LVIA Guidance each effect is considered “in terms firstly of its sensitivity, made up of judgements about: § The susceptibility of the receptor to the type of change arising from the specific

proposal; and § The value attached to the receptor;

And secondly its magnitude, made up of judgements about: § The size and scale of effect- for example, whether there is complete loss of a

particular element of the landscape or a minor change; § The geographical extent of the area that will be affected; and § The duration of the effect and its reversibility.” (para 3.26, p.38) An assessment of the likely landscape and visual effects on the landscape as a resource in its own right and on specific views and on the general visual amenity experienced by people is then undertaken. This embraces all types of effects and includes for example those that are positive/ beneficial and negative/adverse, direct and indirect, and long and short term, as well as cumulative effects. Current guidance notes, “Assessing the significance of landscape and visual effects is a matter of judgement”. (p.46)

Mitigation measures are prepared to prevent/ avoid, reduce and where possible offset any significant landscape and visual effects identified. Enhancement measures may also be identified which are not specifically related to the mitigation of adverse landscape and visual effects, but are “proposals that seek to improve the landscape of the site and its wider setting beyond its baseline condition”.(p.47) In summary, a key requirement of a LVIA is that the basis of judgements “is transparent and understandable, so that the underlying assumptions and reasoning can be examined by others”. (p.46) Methodology The adopted methodology for this Landscape and Visual Impact Assessment is outlined below. The relative significance of effects is assessed using the following terms: Major - a fundamental change to the environment Moderate - a material but non-fundamental change to the environment; Minor - a detectable but non-material change to the environment. None- no detectable change to the environment. Landscape and Visual Baseline Survey and Analysis Understanding the site and surroundings: Collation and review of baseline information covering key features of the physical environment, planning allocation, natural and cultural heritage of the site and surroundings. Review of the landscape and features: The character, condition and value of the landscape are determined through a combination of desk and field study. Relevant designations are identified from a review of planning policies and other designations relating to the area. The nature and sensitivity of landscape features and character is then assessed. Review of the existing visibility and visual amenity: Visibility of the proposed development, visual amenity and potential visual receptors are identified for example, residential properties, public footpaths, transport routes, key viewpoints, etc. The visual baseline including extent of the visibility is determined by using a combination of fieldwork and specialist computer mapping. The nature and sensitivity of views and visual amenity is then assessed.

Landscape and Visual Impact Assessment Landscape and Visual effects are reviewed and identified with reference to: the identification of the potential sources of effect of the proposed development; sensitivity of the landscape and visual resources (nature of receptors): and magnitude of change to the existing landscape and visual environment (nature of effects). Landscape sensitivity is assessed with reference to the degree to which a particular landscape type or area can accommodate change arising from the proposed

development, without detrimental effects on its character. The degree to which a particular landscape type or area can accommodate change arising from a particular development is considered to vary with: § existing landuse § the pattern and scale of the landscape; § visual enclosure/ openness of views, and distribution of visual receptors; § the scope for mitigation, which would be in character with the existing landscape; § the value placed on the landscape.

The sensitivity of visual receptors and views is considered to be dependent on: § the location and context of the viewpoint; § the expectations and occupation of the receptors; § the importance of the view (which maybe determined with respect to its popularity or

numbers of people affected, its appearance in guidebooks, on tourist maps, and in the facilities provided for its enjoyment and references to it in literature and art).

For the purposes of assessment visual receptors are divided into several types, which are considered to be of differing sensitivity, as follows: Residential: Highly sensitive, as they experience prolonged often highly valued views. Recreational: Highly sensitive, for users of recreational facilities including public rights of way, as their attention or interest may be focussed on the landscape and views are often part of their recreational experience (e.g. walkers, cyclists etc). Less sensitive or moderate are people engaged in an outdoor sport or recreation. Workers: Medium to low sensitivity, as may not receive prolonged views, and will be distracted by work. Travellers: Low sensitivity, as their views are constantly changing and attention is focussed on that activity (e.g. motorists). Where travel involves scenic routes awareness of views will be high. Magnitude of change is assessed with reference to the scale or degree of change to the landscape and visual resource, the nature of the effect and its duration. Evaluation of Significance of Effects An assessment of the likely effects is reviewed with reference to landscape features, character, views and visual amenity. Professional judgement and evaluation of the nature or magnitude of effect and the environmental sensitivity of the receptor or location allows the different thresholds of significance of effect to be determined and described using the terms major, moderate, minor or none.

2 Development Plan Extracts SESplan. Adopted 2013 Policy 1B The Spatial Strategy Principles Local Development Plans will: • Ensure that there are no significant adverse impacts on the integrity of

international, national and local designations and classifications in particular National Scenic Areas, Special Protection Areas, Special Areas of Conservation, Sites of Special Scientific Interest, Areas of Great Landscape Value and any other Phase 1 Habitats or European protected species.

• Ensure that there are no significant adverse impacts on the integrity of international and national built or cultural heritage sites in particular World Heritage Sites, Scheduled Ancient Monuments, Listed Buildings, Royal Parks, and Sites listed in the Inventory of Gardens and Designed Landscapes

• Have regard to the need to improve the quality of life in local communities by conserving and enhancing the natural and built environment to create a more healthy and attractive place to live;

• Contribute to the response to climate change, through mitigation and adaptation; and

• Have regard to the need for high quality design, energy efficiency and the use of sustainable building materials.

East Lothian Local Plan. Adopted 2008 Policy DC1: Development in the Countryside & Undeveloped Coast Development, including changes of use, will be acceptable in principle within the countryside and undeveloped coast where it is directly related to agriculture, horticulture, forestry and countryside recreation. Other business use will also be acceptable where it is of an appropriate scale and character for its proposed location in the countryside, it can be suitably serviced and accessed and there are no significant traffic or other environmental impact. Development will also be acceptable in principle in the following circumstances: 1. New Build

a) Leisure, tourism or infrastructure proposals, provided they have a clear operational requirement for a countryside location that cannot reasonably be accommodated within an existing urban or allocated area or, in the case of a proposed development within the undeveloped coast, that cannot be accommodated elsewhere and any potential detrimental impact is outweighed by its social and economic benefits;

In all cases

a. Having regard to its nature and scale, new development must be integrated into the landscape, reflect its character and quality of place, and be compatible with its surroundings;

b. New development must be sited so as to minimise visual intrusion and landscape impact within the open countryside or undeveloped coast, for example, by locating as part of an existing group of buildings, woodland or other well-contained setting, and by respecting and making use of the setting provided by landform or existing landscape features;

c. The proposal must have no significant adverse impact on nearby uses;

d. The proposed development must minimise the loss of prime agricultural land;

e. Account must be taken of the design policy framework contained in the local plan;

f. Suitable access and infrastructure is or can be made available;

g. Where an existing building is demolished, any proposals for a replacement building will be treated as new build and considered as such against Policy DC1.

Policy NH1b: Sites of Scientific Interest Development affecting SSSI’s will only be permitted where it can be demonstrated that: a) the objectives of designation and overall integrity of the site will not be

compromised: or

b) any significant adverse effects on the qualities for which the area has been designated are clearly outweighed by social, economic or environmental benefits of national importance; and

c) there are no alternative solutions.

Policy NH2: Wildlife and Geological Areas

Where damaging development is permitted which affects any designated site of natural heritage value, wherever possible appropriate mitigating measures must be provided to enhance and safeguard the remaining interest.

Policy NH3: Important Local Biodiversity Sites Development which harms a Scottish Wildlife Site or a Listed Wildlife Site (shown on the SWT sites map), a Regionally Important Geological or Geomorphological Site, or a site containing a Priority Habitat or a significant population of Priority Species (as listed in the East Lothian Biodiversity Action Plan), will only be permitted where: 1. any harm to the natural heritage interest is outweighed by the public

benefits of the development; and 2. no suitable alternative sites are available.

Policy NH4: Areas of Great Landscape Value Development that harms the landscape character and appearance of Areas of Great Landscape Value will not be permitted.

Policy NH6: Watercourses and Wetlands There is a general presumption against any engineering works on watercourses in view of the potential impact on the ecology and amenity of an area. Developers should be aware of SEPA’s requirements under the Water Framework Directive. Policy Env 3: Listed Buildings Policy Env 7: Scheduled Monuments and Archaeological Sites 1. Where a proposed development might affect any site or area included in the

East Lothian Sites and Monuments Record (of known or suspected archeological interest), the developer must first undertake and make available to the Planning Authority a professional archaeological assessment and, if necessary, a field evaluation.

2. Development that would harm a site of archeological interest or its setting, particularly a Scheduled Monument, will not be permitted. The only exception to this will be situations where archaeological advice concludes that the significance of the remains is not sufficient to justify their physical preservation in situ when weighed against other material considerations, including the benefits of the proposed development. In such situations, the developer must make proper provision for the excavation, recording, and analysis of the archaeological remains in advance of the commencement of development, any subsequent post excavation work and the publication of the results. Appropriate conditions maybe applied to any planning permissions to achieve this.

3. Where is is feasible within a proposed development to accommodate, preserve and enhance archaeological features or their setting, public access to and interpretation of these features will be expected.

Policy Env 8: Gardens and Designed Landscapes Policy NRG3: Wind Turbines Subject to consistency with other plan policies, proposals for individual turbines or wind farms and associated access tracks and transmissions lines will be supported where: 1. they would not change the existing landscape character in an unacceptable

way 2. they would not have an unacceptable visual impact on the landscape or

townscape including the impact on distinctive public views, landmark buildings or natural features, or routes;

3. they would not have an unacceptable impact from noise at any noise sensitive property including the gardens of such properties however large; the Council will refer to guidelines in PAN 45 and PAN 56 or successor guidance;

4. there would be no demonstrable nuisance from a shadow flicker effect; 5. there would have no unacceptable adverse impacts on hydrogeology or

hydrology;

6. alternative, better, sites are not available; and 7. there are no unacceptable cumulative impacts.

In assessing all proposals the Council will have regard to the findings and recommendations of the Landscape Capacity Study for Wind Turbine Development in East Lothian (May 2005). Policy NRG4: Wind Power Sites- Restoration Prior to the determination of a planning application the planning authority will require wind turbine developers and landowners to enter into a legal agreement to secure removal of the turbines and associated infrastructure and restoration of the site once electricity generation has ceased. Policy INF 3: Infrastructure and Facilities Provision Policy C6: Rights of Way The Council will assert rights of way and bridleways and keep them free from obstruction. Policy C7: Core Paths and Other Routes East Lothian Council, in partnership with the public and landowners, will develop a network of Core Paths. 1. Development that affects a customary path, cycle way or bridle way or an

agreed or proposed Core Path or harms its amenity, will only be permitted where the overall integrity of the route and networks is maintained.

2. The Council will seek reasonable opportunities from developers to create, manage, maintain and improve access through planning conditions or legal agreements.

3. Where development that would affect access to an agreed route is allowed, the Council will secure appropriate access provision through such development by means of planning conditions or other legal agreements.

Policy T1: Development Location and Accessibility Policy T2: General Transport Impact Policy DP1: Landscape & Streetscape Character All new built development, with the exception of alterations and extensions to buildings, must: 1. Be well integrated into its surroundings by responding to and respecting

landform and by retaining existing natural and physical features at the site that are important to the area and incorporate these into the development in a positive way; and

2. Use appropriate hard and soft landscaping to provide an attractive setting for the development; and

3. Where justified by its scale and impact on a locality, provide a landscape structure for the entire development site.

Policy DP2: Design The design of all new development, with the exception of alterations and extensions to existing buildings, must: 1. Be appropriate to its location in terms of its positioning, size, form, massing,

proportion and scale, and use of a limited palate of materials and colours that compliment its surroundings;

2. Create or contribute to a sense of place and complement local character; 3. Where relevant, position and orientate buildings to articulate, overlook,

properly enclose and provide edges to public spaces to create a sense of welcome, safety and security;

4. Maximize opportunities to provide effective access and linkages to the surroundings;

5. Provide a well connected road layout within the site that ensures access for all in the community, favouring where apropriate, walking, cycling, public transport then cars as forms of movement, and

6. Clearly distinguish public space from private space, and protect private space;

7. Ensure privacy and amenity, with particular regard to levels of sunlight, daylight and overlooking;

8. Retain physical or natural features, including watercourses, which are important to the amenity of the area or provide adequate replacements.

Policy DP4: Design Statements Policy DP6: Extensions And Alterations To Existing Buildings All alterations and extensions must be well integrated into their surroundings and be in keeping with the original building. Accordingly, such development must satisfy all of the following criteria: 1. it must not result in a loss of amenity with neighbouring uses or adversely

affect existing residential amenity;

2. for an extension or alteration to a house, it must be of a size, form, proportion and scale appropriate to the existing house, and it must be subservient to and in keeping with the existing building;

3. for an extension or alteration to all other buildings, it must be of a size, form, proportion and scale appropriate to its surroundings and, where the existing building has architectural merit, be in keeping with that building;

4. it must be finished externally in materials with colours and textures which complement existing buildings in the locality and the original building;

5. there must be no significant loss of privacy and amenity for the occupants of existing neighbouring development and occupants of any new development must also enjoy privacy and amenity;

6. it must retain physical or natural features, which are important to the amenity of the area or provide adequate replacements.

Development that does not comply with any of the above criteria will only be permitted where other positive planning and design benefits can be demonstrated.

Policy DP12: Biodiversity Assessment Policy DP13: Biodiversity and Development Sites Policy DP15: Sustainable Urban Drainage Systems Policy DP16: Flooding Policy DP18: Transport Assessments and Travel Plans Policy DP19: Transport Infrastructure Standards- Development Roads, Pedestrian and Public Transport Facilities Policy DP23: Waste Minimisation, Separation, Collection and Recycling Scottish Borders Local Development Plan. Adopted 2016 Policy PMD1: Sustainability In determining planning applications and preparing development briefs, the Council will have regard to the following sustainability principles which underpin all the Plan’s policies and which developers will be expected to incorporate into their developments; a) the long term sustainable use and management of land; b) the preservation of air and water quality; c) the protection of natural resources, landscape, habitats, and species d) the protection of built and cultural resources; e) the efficient use of energy and resources, particularly non renewable resources; f) the minimisation of waste, including waste water and encouragement to its

sustainable management; g) the encouragement of walking, cycling, and public transport in preference to the

private car; h) the minimisation of light pollution; i) the protection of public health and safety; j) the support to community services and facilities; k) the provision of new jobs and support to the local economy; l) the involvement of the local community in the design, management and

improvement of their environment. Policy PMD2: Quality Standards All new development will be expected to be of high quality in accordance with sustainability principles, designed to fit with Scottish Borders townscape and to integrate with its landscape surroundings. The standards, which will apply to all development, are that: Sustainability

a) in terms of layout, orientation, construction and energy supply, the developer has demonstrated that appropriate measures have been taken to maximise the efficient use of energy and resources, including the use of renewable energy and resources such as District heating schemes and the incorporation of sustainable construction techniques in accordance with supplementary planning guidance. Planning applications must demonstrate that the current carbon dioxide emissions reduction target has been met, with at least half of this target met through the use of low or zero carbon technology,

b) It provides digital connectivity and associated infrastructure, c) It provides for Sustainable Urban Drainage Systems in the context of overall

provision of Green infrastructure where appropriate and their after care and maintenance,

d) It encourages minimal water usage for new developments, e) It provides for appropriate internal and external provision for waste storage

and presentation with, in all instances, separate provision for composting facilities,

f) It incorporates appropriate hard and soft landscape works, including structural or screen planting where necessary, to help integration with its surroundings and the wider environment and to meet open space requirements. In some cases agreements will be required to ensure that landscape works are undertaken at an early stage of development and that appropriate arrangements are put in place for long term landscape/ open space maintenance,

g) It considers, where appropriate, the long term adaptability of buildings and spaces.

Placemaking and Design h) it creates developments with a sense of place, based on a clear

understanding of the context, designed in sympathy with Scottish Borders architectural styles; this need not exclude appropriate contemporary and / or innovative design,

i) it is of a scale, massing, height and density appropriate to its surroundings and, where an extension or alteration, appropriate to the existing building,

j) it is finished externally in materials, the colours and textures of which complement the highest quality of architecture in the locality and, where an extension or alteration, the existing building,

k) it is compatible with, and respects the character of the surrounding area, neighbouring uses, and neighbouring built form,

l) it can be satisfactorily accommodated within the site, m) it provides appropriate boundary treatments to ensure attractive edges to the

development that will help integration with its surroundings, n) it incorporates, where appropriate, adequate safety and security measures, in

accordance with current guidance on “designing out crime”. Accessibility

o) street layouts must be designed to properly connect and integrate with existing street patterns and be able to be easily extended in the future where appropriate in order to minimise the need for turning heads and isolated footpaths,

p) it incorporates, where required, access for those with mobility difficulties, q) it ensures there is no adverse impact on road safety, including but not limited

to the site access, r) it provides for linkages with adjoining built up areas including public transport

connections and provision for buses, and new paths and cycleways, linking

where possible to the existing path network; Travel Plans will be encouraged to support more sustainable travel patterns,

s) it incorporates adequate access and turning space for vehicles including those used for waste collection purposes.

Green Space, Open Space and Biodiversity

t) it provides meaningful open space that wherever possible, links to existing open spaces and that is in accordance with current Council standards pending preparation of an up to date open space strategy and local standards. In some cases developer contribution to the wider neighbourhood or settlement provision may be appropriate, supported by appropriate arrangements for maintenance.

u) It retains physical or natural features or habitats which are important to the amenity or biodiversity of the areas or makes provision for adequate mitigation or replacements.

Developers are required to provide design and access statements, design briefs and landscape plans as appropriate. Policy ED9: Renewable Energy Development Renewable Energy developments The Council will support proposals for both large scale and community scale renewable energy development including commercial wind farms, single or limited scale wind turbines, biomass, hydropower, biofuel technology, and solar power where they can be accommodated without unacceptable significant adverse impacts or effects, giving due regard to relevant environmental, community and cumulative impact considerations. The assessment of applications for renewable energy developments will be based on the principles set out in Scottish Planning Policy (2014), in particular, for onshore wind developments, the terms of Table 1: Spatial Frameworks. Renewable energy developments, including wind energy proposals, will be approved provided that there are no relevant unacceptable significant adverse impacts or effects that cannot be satisfactorily mitigated. If there are judged to be relevant significant adverse impacts or effects that cannot be satisfactorily mitigated, the development will only be approved if the council is satisfied that the wider economic, environmental and other benefits of the proposal outweigh the potential damage arising from it….. Supplementary Guidance… Consideration of Wind Energy Proposals The assessment of wind energy proposals will include the following considerations:

• The onshore spatial framework which identifies those areas that are likely to be most appropriate for onshore wind turbines;

• Landscape and visual impacts, to include effects on wild land, and taking into account the report on Landscape Capacity and Cumulative Impact (July 2013) as an initial reference point, the landscape and visual impact assessment for a proposal (which should demonstrate that it can be satisfactorily accommodated in the landscape, and should properly address the issues raised in the 2013 report), and other relevant landscape, visual and cumulative impact guidance, for example that produced by Scottish Natural Heritage;

• All cumulative impacts, including cumulative landscape and visual impact, recognising that in some areas the cumulative impact of existing and consented development may limit that capacity for further development;

• Impacts on communities and individual dwellings including visual impact, residential amenity, noise and shadow flicker;

• Impacts on carbon rich soils (using the carbon calculator), public access, the historic environment (including scheduled monuments and listed buildings, and their settings), tourism and recreation, aviation and defence interests and seismological recording, telecommunications and broadcasting installations, and adjacent trunk roads and road traffic;

• Effects on the natural heritage (including birds), and hydrology, the water environment and flood risk;

• Opportunities for energy storage; • Net economic impact, including local and community socio- economic benefits

such as employment, associated business and supply chain opportunities; • The scale of contribution to renewable energy generation targets, and the

effect on greenhouse emissions; • The need for conditions relating to the decommissioning of developments,

including ancillary infrastructure, and site restoration; and • The need for a robust planning obligation to ensure the operators achieve site

restoration. Developers must demonstrate that they have considered options for minimising the operational impact of wind turbine proposals, including ancillary developments such as tracks. Policy EP1 International Nature Conservation Sites and Protected Species Development proposals, which will have a likely significant effect on a designated or proposed Natura site, which includes all Ramsar sites, are only permissible where:

a) an appropriate assessment has demonstrated that it will not adversely affect the integrity of the site, or

b) there are no alternative solutions, and c) there are imperative reasons of overriding public interest including those of a

social or economic nature. Where a development proposal is sited where there is the likely presence of an European Protected Species, the planning authority must be satisfied that:

a) there is no satisfactory alternative, and b) the development is required for preserving public health or public safety or for

other imperative reasons of overriding public interest including those of a social or economic nature and beneficial consequences of primary importance to the environment, and

c) the development is not detrimental to the maintenance of the population of a EPS at a favourable conservation status in its natural range.

Policy EP2: National Nature Conservation And Protected Species Development proposals which are likely to have a significant adverse effect, either directly or indirectly, on a Site of Special Scientific Interest or habitat directly supporting a nationally important species will not be permitted unless:

a) the development will not adversely affect the integrity of the site, and b) the development offers substantial benefits of national importance, including

those of a social or economic nature, that clearly outweigh the national nature conservation values of the site.

The developer will be required to detail mitigation, either on or off site, of any damage that may be caused by development permissible under the exception criteria.

Policy EP3 Local Biodiversity Developments that would have an unacceptable adverse effect on Borders Notable Species and Habitats of Conservation Concern will be refused unless it can be demonstrated that the public benefits of the development clearly outweigh the value of the habitat for biodiversity conservation. Any development that could impact on local biodiversity through impacts on habitats and species should:

a) aim to avoid fragmentation or isolation of habitats; and b) be sited and designed to maximise adverse impacts on the biodiversity of the

site, including its environmental quality, ecological status and viability; and c) compensate to ensure no net loss of biodiversity through use of biodiversity

offsets as appropriate; and d) aim to enhance the biodiversity value of the site, through use of an

ecosystems approach, with the aim of creation or restoration of habitats and wildlife corridors and provision for their long term management and maintenance.

Policy EP5 Special Landscape Areas In assessing proposals for development that may affect Special Landscape Areas, the Council will seek to safeguard landscape quality and will have particular regard to the landscape impact of the proposed development, including visual impact. Proposals that have a significant adverse impact will only be permitted where the landscape impact is clearly outweighed by social or economic benefits of national or local importance. Policy EP7 Listed Buildings Policy EP8 Archaeology A) National Archaeological Sites Development proposals which would destroy or adversely affect the appearance, fabric or setting of Scheduled Ancient Monuments or other nationally important sites will not be permitted unless:

a) the development offers substantial benefits, including those of a social or economic nature, that clearly outweigh the national value of the site, and

b) there are no reasonable alternative means of meeting the development need. B) Battlefields The Council may support development proposals within a battlefield on the Inventory of Historic Battlefields Register, or a regionally significant site that seek to protect, conserve and/ or enhance the landscape characteristics or important features of the battlefield. Proposals will be assessed according to their sensitivity to the battlefield. C) Regional or Local Archaeological Assets Development proposals which will adversely affect an archaeological asset of regional or local significance will only be permitted if it can be demonstrated that the benefits of the proposal will clearly outweigh the heritage value of the asset. In all the above cases, where development proposals impact on a Scheduled Monument, other nationally important sites, or any other archaeological or historic asset, developers may be required to carry out detailed investigations. Any proposal that will adversely affect a historic environment asset or its appropriate setting must include a mitigation strategy acceptable to the Council.

Policy EP15 Development Affecting the Water Environment Development proposals that seek to bring improvement to the quality of the water environment will be supported. Where a proposal would result in a significant adverse effect on the water environment through impact on its natural or physical characteristics, or its use for recreation or existing river engineering works, it will be refused. Decision making will be guided by an assessment of:

a) pollution of surface or underground water, including water supply catchment areas, as a result of the nature of any surface or waste water discharge or leachate, including from the disturbance of contaminated land;

b) flood risk within the site or the wider river catchment; c) proposals for river engineering works that may be required for fisheries

management, flood defence or erosion control; d) compliance with current best practice on Sustainable Urban Drainage (SUDs)

including avoidance of flooding, pollution, extensive canalisation and culverting of watercourses.

Policy IS5: Protection of Access Routes Development that would have an adverse impact upon an access route available to the public will not be permitted unless a suitable diversion or appropriate alternative route, as agreed by the Council, can be provided by the developer. Policy IS8: Flooding Policy IS9: Waste Water Treatment Standards and Sustainable Urban Drainage

3 SNH Landscape Character Assessment Extracts East Lothian Landscape Character Assessment Key Characteristics and Features Landscape Type: Uplands “The Uplands include three subdivisions of the Southern Uplands range, together with the Pentland Hills, which lie within the Midland Valley. They are characterised chiefly by their altitude, generally ranging from around 300m to over 500m, and have a distinctive land cover dominated by heather moorland, peatland and rough grassland vegetation types….” 1. Lammermuir Plateau Landscape Character Area “The Lammermuir Hills define the geological transition between the predominantly low lying Midland Valley and the older, more resistant rocks of the Southern Uplands…..The Lammermuirs range in height between 348m and 527m, and rise gradually westwards to culminate in the summit of Lammer Law…. The smooth, convex hill slopes are dissected by a complex tracery of valley landforms which vary in scale and appearance from narrow incised gullies formed by minor burns to the wider, flat bottomed valleys of larger rivers such as the Whiteadder Water….. Large expanses of dense, tussocky heather moorland, dappled by rough grasses, form the predominant vegetation cover of the hillsides, occasionally giving way to stretches of rough and improved pasture along the Whiteadder valley. Tree cover is generally absent, a few large scale blocks of coniferous plantation intrude upon the open moorland along the Monynut Water and Dunbar Common. Elsewhere, infrequent clumps of mature deciduous trees, and small coniferous and broadleaved shelterbelts, occur in association with farmsteads or reservoir margins. Occasional patchy scrub is found along stream valleys, together with scrub, bracken and areas of boggy, rush infested ground. Field boundary features are uncommon, although post and wire fences infrequently line roads and access tracks, and farmsteads are occasionally enclosed by low stone walls. Several minor roads wind through the hills. Paths and access tracks leading off these roads maybe locally prominent, where bare soil has been exposed by grading earthworks. A few farmsteads- white- harled traditional or modern in style- are scattered along the valleys of the main watercourses and reservoir edges. Corrugated metal farm sheds are also a common sight throughout the hills. Many of the hill summits are marked by cairns or stone circles, visible reminders of past inhabitants. Striding across the hill plateau, and often silhouetted against the skyline, a major pylon line is highly visible. Visually, the close-knit hill landforms generally coalesce to form an open, exposed plateau, the isolated character of which is emphasised by a lack of settlement or woodland, although internal views within the hill- groups may occasionally be constrained along valleys. Towards the northern periphery of the area, as the upland

landform recedes, panoramic views can be obtained across the hill fringes and coastal plain towards the Forth Estuary and Fife. Positive Attributes

• “Wild land” quality derived from high degree of perceived naturalness of land cover, and relative lack of fragmentation by roads, settlements and other urban features;

• Rich heritage of natural and archaeological features; • Distinctive visual qualities including grandeur of scale and unobstructed, long

distance views. Negative Attributes

• High visual sensitivity adjacent to roads, and on northern margins; • Vulnerability of heather moorland and other semi natural vegetation

communities to changes in management; • Visual intrusion of pylon line and some coniferous plantations.

Key Strategic Aim

• Conserve open, “wild land” character. Guidelines

• Promote management of mature broadleaved tree groups and small plantations;

• Encourage limited expansion of woodland cover through shelterbelts and small woodland particularly in cleughs and valleys, and around farmsteads and other building groups;

• Take opportunities to enhance/ ameliorate impact of existing coniferous plantations at restructuring stage;

• Safeguard landscape setting of archaeological features such as cairns and stone circles;

• Retain small- scale variation in visual character of minor roads in any upgrading schemes;

• Preservation against further hill tracks on visually sensitive slopes; • Protect/ conserve important peatland vegetation communities; • Protect visually- sensitive areas from potential threat of windfarm

development.” Landscape Type: Upland Fringes “Along the northern margins of the upland areas lies a fringe of transitional landscapes. These are differentiated from the true uplands by a more productive range of landcover types including improved grassland, together with arable land, particularly in the east, and coniferous woodland, particularly in the west.” 8. East Lammermuirs LCA “This broad sweeping apron of land fringes the Lammermuir Hills adjacent to Dunbar Common and Monynut Edge….The strongly moulded landform is composed of an intricate interwoven series of smooth, rounded low hills and slopes, dissected by an abundance of streams. The watercourses pass through deeply incised steep- sided valleys (“cleughs” or “deans”), their winding routes often edged by craggy rock

outcrops and exposed slopes. Scattered throughout the area, and hidden within depressions, are a number of small ponds, lochs and reservoirs. The landcover of the area undergoes a transition from south to north, changing from large- scale fields of improved pasture and some good rough grassland to arable ground as the hill slopes begin to merge with the coastal plan. Trim stone walls and post and wire fences, interspersed with occasional hedgerows, define the field network. Hedgerow trees of beech, oak, ash and sycamore although infrequent, are widely scattered throughout the lower arable slopes. The steep valley sides are uncultivated, and are clothed by deciduous woodland or areas of gorse, bracken and scrub. Extensive stretches of ancient sessile oak woodland occur along several cleughs, including Rammer and Denchvie Woods, and Woodhall and Lammermuir Deans. Medium scale coniferous plantations, shelterbelts, tree clumps and areas of mixed woodland are evident across the hill slopes and close to farm buildings. Two highly visible pylon lines extend from east to west across the hill slopes. Numerous minor roads, often edged by stone walls or hedgerows, follow winding courses through the areas, leading to a scattering of mainly traditional farmsteads often dwarfed by large modern sheds or barns…….Lying on the northernmost edge of the slopes, Spott House and its associated dovecote, stable and lodge date from the early 19th century. Also built from deep pink sandstone, the loose knit estate village of Spott is centred around the church and manse. The large – scale, open landscape affords extensive views towards the coast from the smooth domed hill tops. The flowing form of the higher ground, emphasised by curving roads, walls, hedgerows and woodland, contrasts strongly with the heavily textured angular outlines of the stream valleys. Moving from south- north, as the influence of the adjacent hills gives way to views of the coast, the transition is echoed in the change in land cover from grassland to crops. Positive Attributes

• Sharp contrast in landform between smooth upland slopes and steep sided deans;

• Close affinity North Sea coast, including fine open views; • Significant areas of ancient oak woodland; • Distinctive character of dense rural road network, including local features

such as fords and bridges. Negative Attributes

• Visual intrusion from new farm buildings; • Threat from expansion of sand and gravel extraction.

Key Strategic Aim

• Retain distinctive strong local relationships between landcover and topography, emphasising the transition from upland to coastal plain.

Guidelines

• Reinforces visual and ecological contrasts between open hill slopes and steep valley sides;

• Encourage appropriate management of ancient oak woodland; • Encourage further woodland expansion within deans and cleughs, including

fencing to promote natural regeneration; • Promote improved integration of visually sensitive farm building expansion

through farm woodland planting;

• Retain rural character of dense minor road network, including characteristic features such as fords and small bridges;

• Respect small-scale glacial features in responding to pressure for sand and gravel extraction.

Landscape Type: Lowland River Valley “These have been distinguished primarily by their landform, and include the incised headwaters of the River Tyne system, and the gorge-like valleys of the North Esk and South Esk. Their steep slopes carry a relatively high proportion of broadleaved woodland cover.” Landscape Type: Lowland River Valleys 9. Whittinghame Water LCA

Guidelines • Safeguard distinctive architectural integrity and close link with local red

sandstone geology; • Ensure protection and enhancement of characteristic high proportion of mixed

and broadleaved woodland through management and replacement planting; • Protect intimate scale of valley bottom landscape, and of villages, in any future

development proposals; • Seek to support traditional estate management practices to safeguard woodland

enclosure features, and important boundary walls; • Promote replacement of characteristic oak and ash field boundary tree lines. Landscape Type: Coastal Margins The proximity of the Forth Estuary is the dominant influence on a group of landscapes forming the coastal fringe along the northern boundary of the region. The landform is generally flat to undulating, although there are prominent local variations including igneous outcrops, raised beaches and dunelands. Landcover is dominated by arable farmland…interrupted by a concentrated strip of developed urban land stretching from Silverknowes in North West Edinburgh through to Prestonpans in the east. 23. Dunbar Plain LCA Guidelines

• Encourage increase in small farm woodland cover on steep slopes and in deans;

• Promote judicious increase in roadside planting to reduce impact of major visual detractors;

• Protect from sand and gravel extraction; • Take particular account of vulnerability of coastline to further visual intrusion

from all types of development; • Control further unauthorised vehicular access to coastline.

The Borders Landscape Character Assessment Key Characteristics and Features 1. Landscape Type: Dissected Plateau An upland plateau landscape characterised by level- topped hills of heather and coarse grassland, dissected by distinct steep sided valleys. Key Characteristics

• Plateau landform consisting of a series of level- topped hills and ridges; • Individual hill masses separated by steep – sided valley features of differing

scales; • Semi- natural peatland, heather moorland and grassland communities

dominant; • Very low settlement density; • Sense of wildness created by wide horizons and distant, unobstructed views.

1. Lammermuir Plateau LCA Distinctive Features

• Generally lower and more uniform plateau surface; • Valleys less steeply incised; • Extensive coniferous plantations on the southern fringes at Spottiswood;

Harecleugh and Edgarhope Forests. Positive Attributes

• Strong topographic identity. • Grandeur of scale; • High degree of perceived “naturalness” of vegetation cover; • Relative absence of visual detractors and detractors from tranquillity (roads,

settlements, pylon lines); • Isolated, dispersed settlement pattern; • “wild land” quality; • unobstructed, long distance views; • quality of upland landscape and scientific interest reflected in exisitng

designations; • rich archaeological heritage.

Negative Attributes

• Absence of visual screening or backdrop features outwith valleys; • Locally high visual sensitivity on plateau margins (proximity to major road

corridors: A702, A701, A7, A68, A697, A72); • Localised visual intrusion from hill tracks, forest edges, pylon lines; • Relatively low diversity of landscape elements and features; • Semi- natural vegetation communities vulnerable to pressure from grazing,

expansion of forest cover, and visitor pressure; • Heather moorland dependent on economic stability of grouse moor

management. Key Landscape Issues

• Potential loss of wildland character in core areas of plateau; • Potential threats to vulnerable areas of semi- natural vegetation; • Dependence of heather moor on economic stability of sporting use; • Opportunities to reinforce woodland in sheltered valleys.

24. Landscape Type: Upland Valley with Farmland A broad upland vale characterised by its distinctive geology and soil type. Key Characteristics

• Broad flat valley floor with distinct floodplain and meandering river channel. • Evenly sloping valley sides. • Rich red soils derived from Old Red sandstone parent materials • Landcover dominated by arable and improved pasture land, with medium to

large sized fields. • Valley bottom and lower valley sides well treed, with hedgerows, hedgerow

trees, small woodlands and coniferous plantations all locally prominent.

24. Upper Whiteadder LCA Distinctive Features

• Frequent geometrically- shaped coniferous blocks produce chequerboard appearance on valley sides;

• Gorse common on river bluffs and in gullies and tributary valleys.

Positive Attributes • Both valleys have strong topographic and geological identity; • Distinct land cover pattern with well defined field boundary network of

hedgerows and shelterbelts; • Frequent hedgerow trees give a well treed appearance; • Significant designed landscapes in each vale; • Unity of vernacular architecture utilising local stone (red sandstone,

whinstone). Negative Attributes

• Conflict between traffic volume and scale of small settlement townscape; • High visual sensitivity on A68 Trunk Road.

Key Landscape Issues

• Management and reinforcement of existing native hedgerow framework; • Management of existing broadleaf woodland blocks; • Potential forest expansion; • Impact of road improvements within A68 route corridor and existing villages; • Impact of development pressures on existing villages.

4 Viewpoint Photographs No LVIA Viewpoint Photograph Locations 1 Watch Law Access Track - Access Track.

2 Substation Access Track - Public Footpath, Access Track.

3 Bransly Hill Access Track- Public Footpath, Access Track.

5 Visibility The visual appraisal of receptors is based on a grading of degrees of visibility, from “not visible” to “fully open views”. To indicate the degree of visibility of the site (or proposed development) from any location, that continuum has been divided into the following four categories: No View: no view or difficult to perceive. Glimpse View: a transient view or distant view of part of the site or development in the context of a wider view. Partial View: a clear view of part of the site or development; a partial view of most of it; or a distant view in which the site or development forms a relatively small proportion of a wider view. Open View: a panoramic view of most of the site or development, occupying most of the field of vision. Site survey work was undertaken in January 2017. Note: Visibility has been surveyed from the closest point to receptor without the need to enter upon private land. Survey findings are therefore approximate only. * indicates a selected Viewpoint Photograph Location. Viewpoint locations are indicated in Figures 4.3 and 4.4, and Photographs in Figures 4.5a-c.

Receptor Type Visual Receptor Sensitivity Description of Visibility Property North, South, East & West None high n/a Recreation/ Footpaths & Cycle Routes East Substation Access Track*

Viewpoint 2 high glimpse

Bransly Hill Access Track* Viewpoint 3

high glimpse

South None high n/a West Friardykes Dod - Watch Hill

Access Track high partial/ glimpse

Protected Sites North, East, South & West

Lammermuir Plateau AGLV / SLA high partial/ glimpse

North Archaeological Site of Schedulable Quality

high partial/ glimpse

South, East & West None high n/a Roads North Watch Hill Access Track*

Viewpoint 1 low partial/ glimpse

South Bothwell Minor Road low none

6 Visual Effect of Proposed Development The visual effect of the proposed development without mitigation on the selected viewpoints, and visual receptors is detailed below. Visual effect has been assessed from the closest point to the receptor without the need to enter upon private land. Findings are therefore approximate only. * indicates selected Viewpoint Photograph Location. Viewpoint locations are indicated in Figures 4.3 and 4.4, and Photographs in Figures 4.5 a-c.

Receptor Type

Visual Receptor Sensitivity Description of Visibility

Magnitude of Change

Appraisal of Visual Effect

Property North, South, East & West None high n/a Recreation/ Footpaths & Cycle Routes East Substation Access

Track* Viewpoint 2

high glimpse low minor/negligible

Bransly Hill Access Track* Viewpoint 3

high glimpse low minor/negligible

South None high n/a West Friardykes Dod - Watch

Hill Access Track high partial/ glimpse low minor

Protected Sites North, East, South &West

Lammermuir Plateau AGLV/ SLA

high partial glimpse low minor

North Archaeological Site of Schedulable Quality

high partial/ glimpse low minor

South, East & West

None high n/a

Roads North Watch Hill Access

Track* Viewpoint 1

low partial/ glimpse low minor/negligible

South Bothwell Minor Road low glimpse/ none low none

T e c h n i c a l A p p e n d i x 4 . 0 : E c o l o g y

1. Ecology

Introduction 1.1 Survey work carried out in 2013 by MWH concluded that the site does not

support any notable habitats, flora or fauna. A Phase 1 Habitat Survey was carried out at this time and the habitats present were characterised in accordance with published guidance (Joint Nature Conservation Committee, 2010). The site was also evaluated for breeding birds, bats, badger, otter, water vole, red squirrel, reptiles and great crested newt.

Method

1.2 The site was visited by Steven Betts CEnv MCIEEM on 16 March 2016 during which a walkover survey was carried out of the Substation extension area. The objective of the survey was to check the results of the survey work carried out in 2013 to determine whether or not there have been any significant changes in the intervening period.

1.3 During the survey the habitats present were assessed using the Phase 1 Habitat Survey methodology, and target notes (TN) were used to record any notable ecological features.

Results

1.4 The following section describes the baseline conditions within the site at the time of the most recent site visit. Habitats

1.5 Marshy grassland and dry heath/acid grassland mosaic are the two dominant habitats across the site. Marshy grassland is extensive, particularly in the northern part of the site, and it consists of a limited range of commonly occurring species. Areas of dry heath are limited to a few small discrete areas in the north-western part of the site. There was evidence of recent livestock grazing at the time of the site visit. Breeding bird habitat

1.6 The dominance of marshy grassland and dry heath/acid grassland mosaic is likely to reduce the suitability of the site for many bird species but may be utilised by ground-nesting species. During the walkover survey displaying skylark were noted within the site, and meadow pipit was also present in the area. No wader species were noted within the site but a pair of snipe was flushed from marshy grassland by the Tay Burn to the south-east of the site.

Bat Habitat Suitability Assessment

1.7 There are no features suitable for roosting bats within or adjacent to the site. The open moorland habitats may provide some foraging opportunities, however the site is open and exposed and this is likely to render conditions less favourable for foraging bats (see Walsh & Harris,1996a,b). Badger

1.8 No badger setts or field signs were identified during the walkover survey. The habitat present is considered to be poor for sett establishment due to the marshy ground conditions. Otter

1.9 No suitable watercourses or water features are present within the site or within at least 100m of the works area. The nearest watercourse is the Tay Burn which is located to the east of the existing Substation and is separated from the site by a track. Water Vole

1.10 No suitable watercourses or water features are present within the site or within at least 100m of the works area. The nearest watercourse is the Tay Burn which is located to the east of the existing Substation and is separated from the site by a track. Red Squirrel

1.11 The habitat within and adjacent to the site is unsuitable for red squirrel. Reptiles

1.12 The timing of the site visit was too early in the year to detect active reptiles. The dry heath/acid grassland mosaic may provide good common lizard habitat as it is quite tussocky in places, however the damp ground conditions that predominate are likely to reduce the overall importance of the habitat for this species. Adder may also be present in drier areas. Great Crested Newt

1.13 No suitable great crested newt habitat is present within or near the site. The results of the habitat suitability assessment completed in 2013 are considered to still apply.

Impact Assessment Impacts on Habitats

1.14 The site does not support any habitats that are considered to be of ecological importance: marshy grassland and dry heath / acid grassland mosaic are common and widespread in the surrounding area. The loss or disturbance of these habitats is therefore not likely to be significant in ecological terms and is not likely to conflict with any policy protection or legislative considerations.

1.15 Retained habitats should be protected by adopting those measures previously described by MWH (2013). Impacts on Species

1.16 The walkover survey did not reveal any evidence of the presence of protected species although the presence of small numbers of reptiles cannot be ruled out. Ground-nesting birds, in particular skylark and meadow pipit, may be present.

1.17 During the period March to August inclusive (the bird breeding season) it is likely that common ground-nesting birds will be present within the site. Vegetation clearance, soil stripping and earthworks during the construction of the Substation Extension should ideally be undertaken outside of the main breeding bird season, i.e. during the period August to March inclusive. If this is not possible a pre-construction bird survey will be required to ensure that any active nest sites are identified and protected from disturbance and damage to help ensure that the works proceed lawfully (i.e. in compliance with the Wildlife & Countryside Act 1981 as amended). References JNCC (2010). ‘Handbook for Phase 1 Habitat Survey’ Joint Nature Conservation Committee, Peterborough. MWH (2013. Scottish Power Transmission: Crystal Rig Substation Extension Environmental Report, September 2013. Walsh, A.L. and Harris, S. (1996a). Foraging habitat preferences of vespertilionid bats in Britain. Journal of Applied Ecology, 33, 508-518. Walsh, A.L and Harris, S. (1996b). Factors determining the abundance of vespertilionid bats in Britain: geographical, land class and local habitat relationships. Journal of Applied Ecology, 33, 519-529. Legislation Wildlife & Countryside Act 1981 (as amended)

Env Des_319_Crystal Rig_9-3-16

A p p e n d i x 5 . 0 : C u l t u r a l H e r i t a g e

1: Cultural Heritage Assets within the Inner Study Area Site No.

Site Name & Type

Easting Northing HER No. / RCAHMS Database No.

Source(s) Description Cultural Heritage Importance

Magnitude of Effect

Significance of Effect

1 Friardykes Dod / Crystal Rig wind farm; Drainage ditches

366358 669275 MEL9696 HER Aerial photographs show possible remains of rig and furrow cultivation in this area. Field survey (Jones 2008) visited the area and recorded some linear traces in the vegetation which were considered to be a possible indication of the cultivation remains. An archaeological evaluation (Hill & Suddaby 2007) was undertaken by CFA Archaeology Ltd in November 2007 across the area of a proposed Substation for the Crystal Rig Wind Farm, where the possible cultivation remains had been identified. Two types of drainage ditch were recorded. The first ran obliquely across the slope, collecting surface water from the higher slopes of Friardykes Dod and diverting it away from the flatter grassland below, and the second located on the flat grassland and intended to drain it. No dating evidence for either kind of ditch was recorded during the evaluation. Following the evaluation it was concluded that the remains seen on aerial photography are not the remains of rig and furrow cultivation, but the remains of drainage ditches. The northern part of the area of drainage ditches (to the north of the existing Substation) was not subject to evaluation but has been affected by vehicle movements and the construction compound used during the construction of the existing Substation.

Lesser No effect No effect

2 Friardykes Dod; Bank (earthwork)

366403 669147 MEL9941 HER; Field Survey

Field survey in 2008 (Jones 2008) identified the degraded remains of a small section of turf bank to the east of Friardykes. The bank was 0.3m high and 1.5m wide and was orientated east to west. Field survey in 2013 (ScottishPower Transmission 2013) failed to identify any upstanding remains of this turf bank, the location of which is now within the outer fence surrounding the existing Crystal Rig Substation.

Lesser No effect (site already destroyed)

No effect

3 Trackway 365949 366054

669501 668892

N/A Historic Maps; Field Survey

The field survey identified the remains of a trackway surviving as a hollow-way a maximum of 0.2m deep and 3.5m wide with a low bank on the eastern side which was approximately 0.2m high and 2m wide. The trackway is depicted on the First Edition Ordnance Survey map (Haddingtonshire, Sheet XVI, 1855, 6" to 1 mile), and the northern part of it continues to be depicted on the current (2012) edition of the Ordnance Survey map. The trackway forms part of a wider system of trackways which connect with The Herring Road, which lies further to the west, and which was used in the 18th and 19th centuries to transport herring from Dunbar to the markets in Lauder, and to carry home salted herring for use over the winter months.

Local Medium Minor

4 Friardykes Dod; Enclosure

366217 669679 MEL9942 HER Field survey (Jones 2008) identified the remains of a sub-square enclosure south of Watch Law. The enclosure was 8m in length and 7m wide, enclosed by banks 0.4m high and 1m wide. There was a small, grass-covered mound within the enclosure, which was 1m in diameter and 0.4m high. The remains of the enclosure, which are situated to the north of the field boundary, were preserved in situ during the construction of Turbine 9 of Phase II of Crystal Rig wind farm (Moore 2009).

Local None None

T e c h n i c a l A p p e n d i x 6 . 0 : H y d r o l o g y

15 March 2017

CRYSTAL RIG SUB-STATION EXTENSION

Flood Risk Statement, Drainage Strategy and Catchment Hydrology Assessment

RE

PO

RT

Report Number 1526661.502/A0

Distribution:

Environmental Designworks - 1 copy Golder Associates (UK) Ltd - 1 copy

Submitted to:

Environmental Designworks 12 Dryden Place Edinburgh EH9 1RP

FLOOD RISK STATEMENT, DRAINAGE STRATEGY AND CATCHMENT HYDROLOGY ASSESSMENT

15 March 2017 Report No. 1526661.502/A0 i

Table of Contents

1.0 INTRODUCTION ........................................................................................................................................................ 1

2.0 SCOPE....................................................................................................................................................................... 1

2.1 Scoping Process ........................................................................................................................................... 1

2.2 Technical Scope ........................................................................................................................................... 1

2.3 Geographical Scope (Study Area) ................................................................................................................ 1

2.4 Temporal Scope ........................................................................................................................................... 1

3.0 POLICY, GUIDANCE AND LEGISLATION ............................................................................................................... 2

3.1 Policy Context ............................................................................................................................................... 2

3.2 Relevant Legislation, Guidance and Advice ................................................................................................. 4

4.0 BASELINE CONDITIONS .......................................................................................................................................... 4

4.1 Sources of Baseline Information ................................................................................................................... 4

4.2 Ground Conditions ........................................................................................................................................ 5

4.3 Hydrogeology................................................................................................................................................ 6

4.4 Hydrology ..................................................................................................................................................... 6

4.4.1 Surface Water Features .......................................................................................................................... 6

4.4.2 Catchment Characteristics ...................................................................................................................... 6

4.4.2.1 The Tay Burn Catchment ..................................................................................................................... 6

4.4.2.2 The Mossy Burn Catchment ................................................................................................................ 7

4.4.2.3 General Catchment Information ........................................................................................................... 8

4.4.3 Water Quality .......................................................................................................................................... 8

4.5 Abstractions and Water Supplies .................................................................................................................. 8

4.6 Flood Risk ..................................................................................................................................................... 8

4.6.1 Historical Flooding................................................................................................................................... 9

4.7 Designated Sites ........................................................................................................................................... 9

4.8 Drainage at Existing Substation .................................................................................................................... 9

4.8.1 Runoff and Precipitation Drainage .......................................................................................................... 9

4.8.2 Foul Drainage ....................................................................................................................................... 10

4.9 Identification of Hydrology Receptors and Sensitivity ................................................................................. 10

FLOOD RISK STATEMENT, DRAINAGE STRATEGY AND CATCHMENT HYDROLOGY ASSESSMENT

15 March 2017 Report No. 1526661.502/A0 ii

5.0 FLOOD RISK STATEMENT .................................................................................................................................... 10

5.1 Introduction ................................................................................................................................................. 10

5.2 Design Details Relevant to Flood Risk ........................................................................................................ 11

5.3 Flood Risk ................................................................................................................................................... 11

5.3.1 Groundwater Flooding ........................................................................................................................... 12

5.3.2 Surface Water Flooding ........................................................................................................................ 12

6.0 DRAINAGE STRATEGY .......................................................................................................................................... 13

6.1 Construction Period .................................................................................................................................... 13

6.2 Operational Period ...................................................................................................................................... 14

6.2.1 Substation Extension ............................................................................................................................ 14

6.2.2 Internal Access Track ............................................................................................................................ 15

6.3 Decommissioning Period ............................................................................................................................ 15

6.4 Consideration of Design Exceedance ......................................................................................................... 15

7.0 CATCHMENT HYDROLOGY ASSESSMENT ......................................................................................................... 15

7.1 Assessment Method and Significance Criteria............................................................................................ 15

7.2 Receptor Classification ............................................................................................................................... 17

7.3 Design Mitigation ........................................................................................................................................ 17

7.4 Assessment of Initial Effects ....................................................................................................................... 19

7.4.1 Construction .......................................................................................................................................... 19

7.4.2 Operation .............................................................................................................................................. 20

7.4.3 Decommissioning .................................................................................................................................. 21

7.5 Additional Mitigation Measures ................................................................................................................... 22

7.6 Assessment of Residual Effects ................................................................................................................. 22

7.7 Summary of Effects .................................................................................................................................... 22

7.8 Cumulative Effects ...................................................................................................................................... 25

8.0 REFERENCES ......................................................................................................................................................... 25

9.0 GLOSSARY ............................................................................................................................................................. 25

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TABLES

Table 2.1: 2013 Consultation Responses Relating to the Water Environment .................................................................... 1

Table 4.1: Catchment characteristics for Tay Burn (after MWH, 2013) ............................................................................... 7

Table 4.2: Catchment characteristics for Mossy Burn (after MWH, 2013) ........................................................................... 7

Table 4.3: Hydrology Receptors for Assessment of Effects .............................................................................................. 10

Table 5.1: Summary of Greenfield Runoff Rates (after MWH, 2013) ................................................................................ 13

Table 6.1: Attenuation Volume Required to Restrict Site Runoff from a 200 yr Event to the Greenfield Runoff Rate (after MWH, 2013) ............................................................................................................................................ 14

Table 7.1: Sensitivity Criteria for Receptor ........................................................................................................................ 16

Table 7.2: Magnitude of Change Criteria and Definitions .................................................................................................. 16

Table 7.3: Significance of Effect ........................................................................................................................................ 17

Table 7.4: Hydrology Receptors for Assessment of Effects .............................................................................................. 17

Table 7.5: Summary of Effects .......................................................................................................................................... 23

APPENDICES

DRAWINGS Hydrology and Authorised Locations

APPENDIX A 2013 Crystal Rig Substation Extension Environmental Report - Figure 10.4 Proposed Drainage Arrangements

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1.0 INTRODUCTION

This report presents the baseline conditions at the Proposed Development site, a statement relating to flood risk, the drainage strategy and the qualitative technical assessment of the potential effects the Proposed Development will have on catchment hydrology.

For the purposes of this report, ‘the Proposed Development’ jointly refers to the proposed extension to the existing substation at Crystal Rig and the proposed temporary construction compounds. When each element is referred to separately they are referred to as the ‘proposed substation extension’ and the ‘proposed temporary compounds’. The existing substation at Crystal Rig is referred to as ‘the existing substation’.

2.0 SCOPE

2.1 Scoping Process

As part of the 2013 planning application, pre-application consultation was undertaken and a summary of the responses relevant to the water environment are presented in Table 2.1.

Table 2.1: 2013 Consultation Responses Relating to the Water Environment

Consultee Summary of Response

Scottish Environment Protection Agency (SEPA) (letter response 9 August 2013)

The response confirmed that, from the information submitted for consultation in 2013, the proposal to extend the substation was satisfactory and did not require authorisation from SEPA.

Scottish Natural Heritage (SNH) (response received 8 July 2013)

SNH noted that the initial environmental appraisal on which the scope of work was based appeared comprehensive and, at that stage, SNH was not aware of any environmental issues in relation to their remit that had been overlooked. SNH highlighted the importance of the River Tweed SAC (Special Area of Conservation) into which the Tay Burn and Mossy Burn flow. SNH specifically mentioned that the qualifying interests of the SAC would be sensitive to disturbance to the river habitat, including silt and sediment entering the watercourse and smothering gravel beds, suspended solids in the water column, pollution events, and changes in water quality and chemistry. SNH stated that such effects could be avoided through a combination of good design and use of effective mitigation methods (particularly during construction) and that reference should be made to SNH guidance ‘Good practice during windfarm construction’.

These responses informed the scope of the 2013 assessment work and have also been considered in the preparation of this report. No additional scoping consultations have been undertaken as part of this work.

2.2 Technical Scope The technical scope of this report is to present a statement on potential changes to flood risk at the proposed development, present information on the drainage strategy for the Proposed Development that forms part of the design, and undertake an assessment of the potential effects of the Proposed Development on the hydrology of the study area.

2.3 Geographical Scope (Study Area) The study area for the assessment of effects on catchment hydrology covers the Proposed Development itself and an area with a 1 km radius from the Proposed Development boundary. Water features located downstream of the study area that have the potential to be hydraulically connected to the study area are also identified as part of the baseline and considered in the assessment. Only existing access tracks will be used for construction and operation so the study area and assessment does not include these areas.

2.4 Temporal Scope The assessment of effects on catchment hydrology covers the construction, operation and decommissioning periods.

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3.0 POLICY, GUIDANCE AND LEGISLATION

This section presents an overview of the main policies, legislation and guidance relevant to the water environment (including flood risk) and the assessment of effects on it.

3.1 Policy Context

National Planning Framework 3 (NPF, 2014)

Section 4 states that “We will respect, enhance and make responsible use of our natural and cultural assets”. This includes water resources which “contribute to the quality and distinctiveness of our environment” (para. 4.3).

The NPF also states “All of our resources…..require sustainable management to deliver on our climate change commitments and realise opportunities for business and employment” (para. 4.8), which acknowledges the need to balance development with resources and climate change commitments. NPF paragraph 4.25 specifically highlights the importance of managing flood risk in rural areas in response to changing weather patterns.

The targets for the future presented within the NPF state that “90% of water bodies [will be] at good ecological status by 2027”, and good ecology is dependent on good water quality and quantity.

Scottish Planning Policy (SPP, 2014)

SPP reflects the NPF in that it states planning plays an important role in protecting and enhancing the natural environment and that the planning system should “promote protection and improvement of the water environment, including rivers, lochs, estuaries, wetlands, coastal waters and groundwater, in a sustainable and co-ordinated way” (para.194).

The SPP also states that considerations for proposals for energy infrastructure will vary with the scale of the development and area characteristics, but are likely to include cumulative impacts and effects on hydrology, the water environment and flood risk (para.169). This is reiterated in paragraph 202, which states that “Development management decisions should take account of potential effects on landscapes and the natural and water environment, including cumulative effects”.

The SPP specifically highlights that the planning system should promote “a precautionary approach to flood risk from all sources......taking account of the predicted effects of climate change”, locate development “away from functional flood plains and medium to high risk areas” and avoid “increased surface water flooding through requirements for Sustainable Drainage Systems (SuDS) and minimising the area of impermeable surface” (para. 255). Paragraph 266 states that a Flood Risk Assessment will generally be required for applications within areas identified at high or medium likelihood of flooding/flood risk in SEPA’s flood maps.

East Lothian Local Plan, 2008.

Policy NH1a (Internationally Protected Areas) - Development which would have an adverse effect on the conservation interest of a Natura 2000 area (including proposed SPAs or SACs) or a Ramsar site will only be permitted in the following circumstances: a) there are no alternative solutions; and b) there are imperative reasons of over-riding public interest, including those of a social or economic nature.

Policy NH1b (Sites of Special Scientific Interest) - Development affecting SSSIs will only be permitted where it can be demonstrated that: a) the objectives of designation and overall integrity of the site will not be compromised; or b) any significant adverse effects on the qualities for which the area has been designated are clearly outweighed by social, economic or environmental benefits of national importance; and c) there are no alternative solutions.

Policy NH6 (Watercourses and Wetlands) - “There is a general presumption against any engineering works on watercourses in view of the potential impact on the ecology and amenity of an area”.

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Policy DP15 (Sustainable Urban Drainage Systems) - All development proposals that require to be serviced by a SUDS scheme must have such details incorporated at the time of submitting a planning application unless an exceptional circumstance, such as ground conditions, prevent such provision. This must be supplemented by a Drainage Impact Assessment that shows the impact of a 1 in 200 year rainstorm event. SUDS schemes should be designed accordingly so that if this event occurs, flooding will not be higher than 300 mm below floor level. In addition, proposals must adopt an ecological approach to surface water management and exploit opportunities for habitat creation or enhancement by forming, for example, wetlands or ponds.

Policy DP16 (Flooding) - Development that is likely to cause unmanageable flood risk, either on or off site, or would require additional unplanned public investment for flood protection works, will not be permitted.

Scottish Borders Local Development Plan (adopted May 2016)

Policy EP1 (International Nature Conservation Sites and Protected Species) – Development proposals which will have a likely significant effect on a designated or proposed Natura site, which includes all Ramsar sites, are only permissible where: a) an appropriate assessment has demonstrated that it will not adversely affect the integrity of the site, or b) there are no alternative solutions, and c) there are imperative reasons of overriding public interest including those of a social or economic nature.

Policy EP2 (National Nature Conservation Sites and Protected Species) – Development proposals which are likely to have a significant adverse effect, either directly or indirectly, on a Site of Special Scientific Interest or habitat directly supporting a nationally important species will not be permitted unless: a) the development will not adversely affect the integrity of the site, and b) the development offers substantial benefits of national importance, including those of a social or economic nature, that clearly outweigh the national nature conservation value of the site.

Policy EP15 (Development Affecting the Water Environment) – Development proposals that seek to bring improvement to the quality of the water environment will be supported. Where a proposal would result in a significant adverse effect on the water environment through impact on its natural or physical characteristics, or its use for recreation or existing river engineering works, it will be refused. Decision making will be guided by an assessment of: a) pollution of surface or underground water, including water supply catchment areas, as a result of the nature of any surface or waste water discharge or leachate, including from the disturbance of contaminated land; b) flood risk within the site or the wider river catchment; c) proposals for river engineering works that may be required for fisheries management, flood defence or erosion control; d) compliance with current best practice on Sustainable Urban Drainage (SUDS) including avoidance of flooding, pollution, extensive canalisation and culverting of watercourses.

Policy IS8 (Flooding) – At all times, avoidance will be the first principle of managing flood risk. In general terms, new development should therefore be located in areas free from significant flood risk. Development will not be permitted if it would be at significant risk of flooding from any source or would materially increase the probability of flooding elsewhere. The ability of functional flood plains to convey and store floodwater should be protected, and development should be located away from them.

Policy IS9 (Sustainable Urban Drainage) - Surface water management for new development, for both greenfield and brownfield sites, must comply with current best practice on sustainable urban drainage systems to the satisfaction of the council, Scottish Environment Protection Agency (where required), Scottish Natural Heritage and other interested parties where required. Development will be refused unless surface water treatment is dealt with in a sustainable manner that avoids flooding, pollution, extensive canalisation and culverting of watercourses. A drainage strategy should be submitted with planning applications to include treatment and flood attenuation measures and details for the long term maintenance of any necessary features.

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3.2 Relevant Legislation, Guidance and Advice

The legislation, guidance and advice that has been considered relevant to this topic (and to the preparation of an Environmental Report in the format of an Environment Impact Assessment) includes the following:

The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011.

The Scottish Government Planning Circular 3 2011 “The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011”.

The Scottish Government Planning Advice Note 1/2013 Environmental Impact Assessment.

Water Environment and Water Services (Scotland) Act 2003.

Water Environment (Controlled Activities) (Scotland) Regulations 2011 and its 2013 amendment.

The Flood Risk Management (Scotland) Act 2009.

The Scottish Government Flood Risk Planning Advice, June 2015 (which supersedes Planning Advice Note 69 on Flood Risk).

Scottish Natural Heritage guidance entitled ‘Good practice during windfarm construction’, version 3 dated September 2015.

Scottish Environment Protection Agency Pollution Prevention Guidelines (PPGs).

4.0 BASELINE CONDITIONS

4.1 Sources of Baseline Information

This baseline section has been collated from the previous Environmental Report (ER) and 2016 Environmental Report Addendum (ERA) submitted for the original proposed Crystal Rig Substation Extension. Details of these reports are as follows:

Crystal Rig Substation Extension Environmental Report, prepared by MWH UK Ltd on behalf of Scottish Power Transmission. Version 02 dated 11 September 2013; and

Crystal Rig Substation Extension Environmental Report Addendum, prepared by Environmental Designworks for Scottish Power Energy Networks. Final Version dated April 2016.

The baseline conditions relating to hydrology, drainage and flood risk were originally presented in Chapters 8, 9 and 10 of the 2013 Environmental Report. It is understood that there have been no notable changes to the Proposed Development area since that time; therefore, no new site visits have been made to inform the baseline of this assessment. This baseline is, therefore, largely compiled using the information presented in the 2013 Environmental Report and the subsequent addendum where no other source of information is referenced. Golder has not reviewed the baseline information or calculations presented in the 2013 work.

Where additional information has been required, or the currency of existing information has been checked, the following sources have been used:

British Geological Survey (BGS) Geology Mapping. http://mapapps2.bgs.ac.uk/geoindex/home.html, accessed 17 February 2017.

Scotland’s Soils. 1:250,000 National Soil Map of Scotland. http://www.soils-scotland.gov.uk/data/soil-survey, accessed 17 February 2017.

Scottish Environment Protection Agency (SEPA) Flood Risk Management Strategy: Tweed Local Plan District, version 1.1 dated February 2016.

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Scottish Environment Protection Agency (SEPA) Flood Risk Mapping. http://map.sepa.org.uk/floodmap/map.htm, accessed 16 February 2017.

Scottish Environment Protection Agency (SEPA) River Basin Management Plan Mapping. http://gis.sepa.org.uk/rbmp/, accessed 17 February 2017.

Scottish Natural Heritage. Designated Site Mapping. http://gateway.snh.gov.uk/sitelink/searchmap.jsp, accessed 17 February 2017.

For the purposes of the work relating to flood risk, drainage and catchment hydrology, it has been assumed that the current baseline is also representative of the future baseline (i.e. conditions present at the start of construction).

4.2 Ground Conditions

The Proposed Development is located in an area dominated by undulating hills. It will be constructed on ground to the west of the existing substation. The topography of the area slopes downwards from west to east. The ground at the Proposed Development currently encompasses the northeast slope of the rounded hill of Friar Dyke Dodd. The summit of the hill to the southwest is 334 m AOD. The existing substation to the east is an area of man-made flat ground at an elevation of approximately 298 m AOD.

The ground cover/vegetation in the area largely comprises rough and marshy grassland with localised man-made features (e.g. drainage ditches, and compound areas and access tracks associated with the Crystal Rig wind farm). There are very few trees at the Proposed Development site or in the immediate area. There are patches of woodland within 0.5 km and areas of plantation within 1 km.

The soils mapped in the proposed substation extension and temporary compound areas (Scotland’s Soils, 2017) comprise Brown Soils and Blanket Peat, which are both of the Ettrick Association. The brown soils are mapped in the southern and western parts of the proposed substation extension area. They are described as comprising brown earth derived from the wacke bedrock geology (see below). The blanket peats are mapped in the northern parts of the proposed substation extension area and the northern of the proposed temporary compound areas. These are described as comprising dystrophic blanket peat with peaty gleys. Dystrophic blanket peats are rain-fed, mineral-poor and usually support vegetation communities dominated by heathers and nutrient -poor grasses.

The presence of peat was noted as part of the ecology survey undertaken in May 2013. Blanket Bog was only mapped in a small area to the north and west of the proposed temporary compound areas (i.e. not in an area of Proposed Development). The rest of the vegetation in the Proposed Development areas was mapped as dry heath/acid grassland mosaic or marsh/marshy grassland.

The superficial geology mapped in the area (BGS, 2017) comprises alluvial deposits and Glacial Till. The Alluvial material (typically a mixture of clay, silt, sand and gravel) is mapped as being confined to the routes of the surface watercourses. The Glacial Till (typically a poorly sorted deposit dominated by clay with other material from silt to boulder size included within in) is mapped as being located in the lows (valleys and saddles between hills). There are no superficial deposits mapped on the areas of higher ground away from the watercourses. In relation to the Proposed Development area itself, there are Till deposits mapped in the northern part around the proposed temporary compounds and there are no superficial deposits mapped to the west or south of the existing substation where the proposed substation extension and proposed southern temporary compound are proposed.

The bedrock geology beneath the proposed substation extension and compound areas is mapped (BGS, 2017) as comprising wacke deposits that are part of the Gala Group. These are described as graded beds that include wacke sandstone, siltstone and mudstone.

The land around the Proposed Development drains poorly and, as a result, there are commonly areas of wet/saturated ground in the area, particularly following precipitation.

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4.3 Hydrogeology

The bedrock geology is part of the ‘Lammermuir bedrock and localised sand and gravel drift aquifer’ groundwater body within the Solway Tweed River Basin District. The groundwater body was classified in 2008 as having good status for both quantity and chemistry. The targets for this water body under the Water Framework Directive are to maintain the good status and that “no deterioration in status occurs, unless caused by a new activity providing significant specified benefits to society or the wider environment”1. The water body is described by SEPA as having an area of 271.66 km2 and is associated with Bothwell Water and Whiteadder Water (see Section 4.4). The ‘Lammermuir bedrock and localised sand and gravel drift aquifer’ is also a drinking water protected area.

The British Geology Society (BGS, 2107) classifies the Gala Group bedrock aquifer as low productivity. Groundwater storage and flow occurs in the near surface weathered zone and through secondary fractures.

There are no investigation results to provide site-specific information on groundwater levels. The poor draining, peaty nature of the soils and marshy grassland ecology suggests that the soils are often saturated; particularly after periods of prolonged rainfall.

Groundwater may be encountered within the Glacial Till in localised lenses of the more silty and sandy parts of the Till, but lateral and vertical flows may be limited where clay dominates. It is likely that water will be encountered within the soils and fractured upper horizons of the bedrock aquifer. Flow will most likely follow topography and, therefore, groundwater flow beneath the Proposed Development area will be generally towards the east and the Tay Burn.

There is likely to be a hydraulic connection between groundwater and surface water in the catchments. Near surface groundwater is likely to provide baseflow to the burns and feed springs/seeps in the area.

4.4 Hydrology

4.4.1 Surface Water Features

There are no surface watercourses or water bodies on the Proposed Development. The nearest watercourse is a tributary of the Tay Burn, which at its closest passes approximately 0.25 km east of the Proposed Development. A tributary of the Mossy Burn is located approximately 0.75 km to the west. These watercourses are show in Drawing 1.

The tributary of the Tay Burn originates approximately 0.5 km north of the Proposed Development and flows parallel on the western side of the existing access track before passing under the tack through a culvert approximately 0.3 km north of the Proposed Development. It then flows towards the southeast (passing the Proposed Development), south then southwest where it converges with the Mossy Burn approximately 1.4 km south of the Proposed Development and continues to flow southeast as the Bothwell Water. The Bothwell Water is part of the Whiteadder Water Catchment, which ultimately discharges into the River Tweed.

4.4.2 Catchment Characteristics

The Proposed Development is located between the Tay Burn and the Mossy Burn, which (as highlighted above) converge to the south of the site and become Bothwell Water. Information on the characteristics of the catchments of these two burns was presented in the 2013 assessment and is reproduced here as no changes are known to have occurred since that report was submitted.

4.4.2.1 The Tay Burn Catchment

The tributary of the Tay Burn located to the east of the Proposed Development has a catchment area of 1.87 km2 and is an ungauged watercourse flowing to the south before converging with the Mossy Burn to flow into Bothwell Water.

1 RBMP Water body information sheet for water body 150141 (Lammermuir bedrock and localised sand and gravel aquifers), dated 15 March 2010

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The Tay Burn is located on marshy grassland. The catchment characteristics presented in 2013 were derived from the Flood Estimation Handbook (FEH) CD-Rom and are shown in Table 4.1.

Table 4.1: Catchment characteristics for Tay Burn (after MWH, 2013)

Parameters Values Description

AREA 1.87 Catchment drainage area (km2) ALTBAR 319 Mean altitude of catchment (m AOD) ASPBAR 167 Mean direction of drainage path slopes (degrees) FARL 1 Index of flood attenuation due to lakes (1 is no attenuation) FPEXT 0.0228 Fraction of the catchment inundated by a 100-year flood RMED-1H 10 Median annual maximum 1-hour rainfall (mm) RMED-1D 47.7 Median annual maximum 1-day rainfall (mm) RMED-2D 58.6 Median annual maximum 2-day rainfall (mm) SAAR 851 Standard-period (1961-1990) average annual rainfall (mm) SAAR4170 926 Standard-period (1941-1970) average annual rainfall (mm) SPRHOST 42.9 Standard Percentage Runoff URBEXT 1990 0 Extent of urban and suburban cover in 1990 URBEXT 2000 0 Extent of urban and suburban cover in 2000

The Tay Burn catchment has an average annual rainfall of 851 mm. Information presented in the 2013 assessment and taken from the FEH CD ROM (Catchment Characteristics for Tay Burn) catchment is also prone to intense rainfall events with a median annual maximum 1-day rainfall of 47.7 mm.

4.4.2.2 The Mossy Burn Catchment

The tributaries of the Mossy Burn that are located to the west of the Proposed Development have a catchment area of 4.84 km2 and is an ungauged watercourse flowing towards the southeast into the Mossy Burn and then into Bothwell Water. The catchment characteristics presented in 2013 were derived from the FEH CD-Rom and are shown in Table 4.2.

Table 4.2: Catchment characteristics for Mossy Burn (after MWH, 2013)

Parameters Values Description

AREA 4.84 Catchment drainage area (km2) ALTBAR 3.18 Mean altitude of catchment (m AOD) ASPBAR 151 Mean direction of drainage path slopes (degrees) FARL 1 Index of flood attenuation due to lakes (1 is no attenuation) FPEXT 0.0139 Fraction of the catchment inundated by a 100-year flood RMED-1H 9.9 Median annual maximum 1-hour rainfall (mm) RMED-1D 46.9 Median annual maximum 1-day rainfall (mm) RMED-2D 59.1 Median annual maximum 2-day rainfall (mm) SAAR 846 Standard-period (1961-1990) average annual rainfall (mm) SAAR4170 879 Standard-period (1941-1970) average annual rainfall (mm) SPRHOST 51.59 Standard Percentage Runoff URBEXT 0 Extent of urban and suburban cover in 1990 URBEXT 0 Extent of urban and suburban cover in 2000

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4.4.2.3 General Catchment Information

The following information was also presented in the 2013 assessment and is considered to remain applicable for both catchments:

The runoff rates are high, especially for Mossy Burn (SPRHOST=51.59). The runoff rates for the Tay Burn are lower, but also quite high (SPRHOST=42.9). These values indicate that 42.9 % to 51.59 % of rainfall falling on the catchments flows into the Tay Burn and Mossy Burn, respectively.

Both catchments are “wet” and receive an average annual rainfall from 846 to 926 mm (see SAAR and SAAR4170 values in the tables above) and are prone to intense rainfall events (RMED-1D and 2D are 47.7 mm and 58.6 mm for Tay Burn; RMED-1D and 2D are 46.9 mm and 59.1 mm for Mossy Burn) with associated high runoff rates.

A small fraction of the catchments are inundated by a 1 in 100 year flood event (FPEXT is 0.023 for Tay Burn and 0.014 for Mossy Burn) confirming that there is limited fluvial flood risk for this site, as described by the Flood Risk Statement (Section 5.0).

Both catchments are fully rural (URBEXT2000 is null for Tay Burn and Mossy Burn).

4.4.3 Water Quality

Bothwell Water (into which the Tay and Mossy burns flow) is a classified surface water body under the Water Framework Directive. In 2008, it was classified as having ‘good’ overall status (‘good’ ecological status and a chemical status of ‘pass’). The targets for this water body under the Water Framework Directive are to maintain the good status and to “ensure that no derogation from good status occurs unless caused by a new activity providing significant specified benefits to society or the wider environment”2. Bothwell Water surface water body is associated with the Whiteadder Water and River Tweed Protected Areas and groundwater in the ‘Lammermuir bedrock and localised sand and gravel drift aquifers’.

4.5 Abstractions and Water Supplies

No springs, private or public water supplies or licensed abstractions from surface water or groundwater were identified in this area as part of the 2013 study.

Scottish Water was contacted in 2013 for details of water assets. The information it provided indicated that the closest surface water catchment is Cranshaws for Whiteadder Reservoir, which is located approximately 3 km to the west of the Proposed Development. The catchment for Thorters Reservoir, which is an emergency source, is located approximately 4 km to the west of the Proposed Development.

SEPA was contacted as part of the 2013 assessment baseline for details of licensed activities under the Water Environment (Controlled Activities) (Scotland) Regulations (including water abstractions and discharges) in the Proposed Development and surroundings. The locations of these that were included in the 2013 assessment are reproduced on Drawing 1.

It is stated in the 2013 assessment baseline that ELC was contacted as part of a previous study for details of private water supplies in the area. The Council did not have any records of private drinking water supplies in the Proposed Development.

4.6 Flood Risk

The 2017 SEPA flood map indicates that there is no risk of flooding at the sites of the proposed substation extension or the proposed temporary compounds. There are localised areas of flood risk from rivers or surface water associated with the routes of the Tay Burn and the Mossy Burn, but the areas that are likely to flood are constrained to the watercourse channels and the immediate surrounds. There are no areas mapped as being at risk from groundwater flooding.

2 RBMP Water body information sheet for water body 5120 (Bothwell Water), dated 15 March 2010

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The Proposed Development is located just upstream of the area covered by the Flood Risk Management Strategy for the Tweed Local Plan District (SEPA, 2016). The watercourses downstream of the Proposed Development are within the Tweed catchment and the Scottish Borders Council area that is covered by the Tweed Plan. The Whiteadder Water (of which the Tay Burn is a tributary) flows into the potentially vulnerable area 13/02 (Preston), which is identified as being at risk from river flooding.

4.6.1 Historical Flooding

A significant flood recorded within the Preston potentially vulnerable area was in 1948 and was caused by a third of expected annual rainfall falling over a six day period, which caused flooding in the rivers Tweed, Blackadder, Whiteadder, Till and Eye Water (SEPA, 2016).

4.7 Designated Sites

There are no designated sites on the Proposed Development or within the study area (SNH, 2017). The nearest designated sites are Sites of Special Scientific Interest (SSSI) located approximately 1.5 km to the north-northeast and approximately 2 km to the north-northwest (see Figure 4.0 of the main ). The SSSI to the north-northeast is Woodhall Dean, which is an area of upland oak woodland that is under pressure from forestry and grazing. The SSSI to the north-northwest is Rammer Cleugh, which is designated for its upland oak woodland and example of Quaternary geology. The geology is recorded as being under pressure from invasive species. Neither are designated for features that are heavily reliant on the water environment or are designated by SNH as being under pressure from water related concerns. There is a third SSSI located approximately 2.5 km to the east; Lammermuir Deans. This SSSI is designated for its valley fen wetlands, upland mixed ash woodland, subalpine calcareous grassland habitat and its examples of fluvial geomorphology. The only pressure to these features recorded by SNH is over-grazing in the woodland. The valley fen element of the SSSI may be water dependent, but it is not located in the Whiteadder Water Catchment.

The River Tweed, into which Bothwell Water ultimately discharges, is designated as a SSSI and a Special Area of Conservation (SAC). It is designated for fish species (Atlantic Salmon, Brook Lamprey, River Lamprey and Sea Lamprey), Otter and its freshwater habitats. Many of these are listed as being under pressure from water quality and flows. The SSSI is designated for the same species and habitats, as well as beetle, fly and vascular plant assemblages. At its closest, the River Tweed SAC is approximately 3 km south-southeast of the Proposed Development.

4.8 Drainage at Existing Substation

4.8.1 Runoff and Precipitation Drainage

The proposed substation extension lies downstream of a hill slope catchment, with around 10 ha draining towards the western boundary of the Proposed Development.

The existing development is already bounded by an earth bund that extends around its western boundary. A swale is located around the outside base of the bund to intercept water that runs off from the west towards the substation. The swale is approximately 4.8 m wide from the top of its banks, 0.7 m deep and 500 m in length. Water from this swale is conveyed around the outer edge of the bund and discharged to ground to the east through culverts that run under the existing access track near the northern and southern extents of the existing substation.

A filter trench is located on the inside of the bund at its base and runs around the perimeter of the existing substation footprint. This is approximately 1 m wide and intercepts flows from inside the bund. Water intercepted by this is also discharged to ground to the east through culverts that run under the existing access track near the northern and southern extents of the existing substation.

Discharges of the intercepted water to the land east of the existing substation mimic the original direction of surface water runoff, which would naturally have followed the gradient from west to east. The land onto which the discharges occur is marshy grassland on soils that are commonly saturated; therefore, surface water flow continues overland predominantly, before reporting to the Tay Burn and its tributaries.

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Surface water that originates from within the substation footprint (i.e. on the flattened ground inside the filter trench) is managed by a series of pipes within the gravel base that direct water to a catch pit on the eastern side of the existing substation compound. This catch pit discharges to ground to the east via a culvert that runs under the existing access track near the middle point of the north-south eastern boundary of the existing substation.

4.8.2 Foul Drainage

Foul drainage at the existing substation is managed via a mound soakaway located on the eastern boundary of the existing substation compound. The soakaway has a mound filter system for the treatment of domestic waste with a sand filter. Topsoils cover the soakaway. The soakaway discharges treated effluent to ground under SEPA CAR licence CAR/R/R/1027767).

4.9 Identification of Hydrology Receptors and Sensitivity

Using the baseline information presented in this Section, the key water environment receptors are considered to be surface water and groundwater. The receptors are presented in Table 4.3.

Table 4.3: Hydrology Receptors for Assessment of Effects

Receptor Reason

The Tay Burn

The Tay Burn feeds into the River Tweed SAC and SSSI. Changes to the flow into, flow in, or quality of, the Tay Burn could have knock-on effects to the quality of watercourses downstream. Changes to the geomorphology could affect flows, quality and the habitats dependent on these.

Groundwater in the Gala Group

Groundwater is likely to provide baseflow to the Tay Burn. The Proposed Development is in a protected drinking water area, but the likelihood of groundwater being used directly as a water supply at locations close to the site is limited due to the low productivity status of the aquifer.

The Proposed Development Consideration of risks from flooding to the Proposed Development.

5.0 FLOOD RISK STATEMENT

5.1 Introduction

A statement regarding flood risk and the original substation extension proposals was original presented in the 2013 Environmental Report. The conclusions of that statement (and assumptions on which they were based) were revisited as part of the addendum issued in 2016 when the substation extension design was originally intended to be modified through a non-material variation. The previous work highlighted that the Proposed Development is on a very small scale, there are no buildings and it would be manned infrequently. The conclusions of the assessment were that the location of the site meant that no significant risk to the development from fluvial flooding was expected, and that the development will not increase flood risk elsewhere.

A full Flood Risk Assessment (FRA) has not been prepared for this submission as the development is not in an area of flood risk, there are no buildings proposed as part of the development (or in the vicinity) that could be at risk of being damaged by flooding. There was also no requirement for a FRA as part of consultation exercises prior to the 2013 assessment. This statement regarding flood risk is presented in order to inform mitigation intended to limit the potential for changes to flood risk in the surrounding area (including downstream within the catchment) as a result of the Proposed Development. It has been prepared for the modified substation extension design (i.e. the original extension proposal plus the addendum proposals) by collating the existing information available from the 2013 and 2016 reports.

The drainage strategy presented later in this report outlines the proposed surface water management of the development and is presented to compliment this flood risk statement and support the assessment of effects on the hydrological catchment.

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5.2 Design Details Relevant to Flood Risk

The Proposed Development includes the extension to the existing substation (including perimeter bund and extension of existing Sustainable Urban Drainage Systems - SUDS), the proposed temporary compounds, and the construction of a short section of surfaced internal access track within the substation extension.

The previously consented substation extension has a footprint of approximately 1.3 ha. Of that area, approximately 0.1 ha (~7.5%) will be impermeable hardstanding and the rest will comprise a more permeable gravel base. The later increase in substation extension dimensions by 5 m on the western side and by 7 m on the northern side will almost entirely comprise a gravel base, which is line with the SPP promoting minimisation of impermeable surfaces. The only impermeable surfaces will be the concrete pad footings for the substation equipment and a short length of surfaced, 3 m wide access track within the proposed substation compound.

No buildings are proposed as part of the development. There will be no tree removal and none of the construction activities will take place in, or within 50 m of, a watercourse.

The proposed substation extension area will slope downwards from west to east where it will join the western boundary of the existing substation. The existing earth bund will be extended westwards around the proposed substation extension area and will have a maximum elevation of 322 m AOD. An existing swale located at the top of the earth bund will also be extended under the proposed works and will capture runoff from the grassy marshland immediately upstream.

During decommissioning of the substation, the above ground infrastructure and impermeable hardstanding will be removed. The site will then be reinstated to its initial condition. Runoff rates are expected to be returned to as close to pre-development conditions as is reasonably practicable.

The proposed temporary compounds will be used for storage of soils to be reused during development, storage of stone for ongoing maintenance of the existing access track, temporary storage of material to be removed from site, and for management of surface water during construction. For the purposes of this assessment, it has been assumed that the proposed temporary compounds will be constructed by removal and storage of soils for reuse and temporary surfacing using permeable gravel/rock chipping materials. The areas required for construction will be returned to their initial state following construction works (i.e. gravels removed, re-profiled to the original topography, and soils replaced).

5.3 Flood Risk

This section considers the following aspects:

Groundwater flood risk to the Proposed Development; and

Surface water flooding, including:

Fluvial (i.e. from watercourses) and pluvial (i.e. from pooling of precipitation) flood risk to the Proposed Development;

Changes in surface water run-off from adjacent moorland; and

Changes in surface water run-off generated as a result of the Proposed Development.

The Proposed Development is not located in an area at risk from flooding from the coast or reservoirs. The Proposed Development is also not located near the coast or any reservoirs. Therefore, this assessment does not consider the risk presented to the Proposed Development from coastal or reservoir flooding, or any changes to coastal or reservoir flooding that could occur due to the presence of the Proposed Development.

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5.3.1 Groundwater Flooding

The 2017 SEPA flood map indicates that there is no risk of groundwater flooding at the Proposed Development.

The 2013 assessment highlighted that previous ground investigations indicated the ground beneath the site and its surrounding area comprises peaty soils, which offer poor drainage and, therefore, potentially high water tables. Observations presented in that report also indicated that the ground is commonly saturated due to poor drainage of precipitation. This does not represent groundwater flooding per se, but does show that the ground and near surface may be saturated, particularly at times following prolonged or intense periods of precipitation.

The location and ground levels at the proposed substation extension mean that cut-and-fill construction activities will take place. The excavated material will predominantly be reused on site while levelling the ground and constructing bunds. Boggy ground can be expected at the surface and water may be encountered in the sub-surface during construction.

The proposed substation extension will ultimately be built on a gravel base, which will raise this part of the development off the natural ground and provide drainage discussed in the next section, so the risk to the proposed substation extension from groundwater flooding is considered to be low.

5.3.2 Surface Water Flooding

There are no surface watercourses or waterbodies located in the Proposed Development areas. The 2017 SEPA flood map indicates that there is no risk of flooding from rivers or surface water at the sites of the proposed substation extension or the proposed temporary compounds. There are localised areas of flood risk from surface water or rivers associated with the routes of the Tay Burn. The nearest mapped risk from surface water flooding is on a tributary of the Tay Burn, which is located over 200 m to the east. The nearest mapped risk from river flooding is on the Tay Burn approximately 1 km southeast of the Proposed Development.

There are no proposals to change the channel morphology of any of the existing watercourses as part of the Proposed Development, or to undertake construction activities within watercourses.

In 2012, Kaya Consulting conducted a desk study to assess fluvial flood risk from this tributary to the proposed substation extension. The finding of the assessment is therefore applicable to this study and are presented here.

“The catchment of the channel is no more than 15 ha. Based on the IH124 small catchments method the 1 in 200 year flow for this stream is estimated to be of the order of 330 l/s. The channel is around 1 m wide at the top of bank and 1 m deep. Based on a simple application of Manning’s equation with bed slope of 1 in 100 (from available Ordnance Survey mapping) and Manning’s n of 0.05, the channel is predicted to be able to pass the 200 year flow at a depth of less than 0.5 m, i.e., around 0.5 m below the bank level.”

In the event of a blockage to the culvert of the tributary of the Tay Burn, located north of the Proposed Development, the 2013 Assessment identified that the water would back up, overtop the channel banks, flow downhill towards and eventually discharge to the Tay Burn. The elevation of the land at the Proposed Development is currently between approximately 2 m and 20 m higher than the land either side of the watercourse, and the proposed substation extension will be 4 m to 5 m higher than the existing ground level. Therefore, the risk of flooding from this surface watercourse (during this scenario) on the Proposed Development is negligible.

Any run-off towards the proposed substation extension from the surrounding land will be captured and managed using a swale around the base of the perimeter bund. The existing filter trench will be extended around the perimeter of the proposed substation extension (i.e. inside the bund) to intercept surface water flows generated from the earth bund in towards the proposed substation extension. Precipitation that falls within the proposed substation extension itself will either permeate to ground or be collected by a network of pipes before being directed to a catch pit. Water collected through all three methods will be discharge via culverts under the existing access track to ground to the east. More details about the drainage design can be found in the Drainage Strategy chapter of this report.

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The use of SUDS that intercept water from the west and discharge water to the east aims to mimic the original drainage. Discharge to watercourse will be limited to current greenfield runoff rates in order to help reduce the potential for flooding due to rapid high volume discharges. Table 5.1 describes the runoff rate for a range of return periods that were calculated as part of the 2013 assessment using Micro Drainage WinDes software suite, which applies the Institute of Hydrology Small Catchment Equation (IH124). These calculations were based on the original substation extension area of 1.3 ha. The later increase in proposed substation extension area by a strip 7 m wide along the northern side and 5 m along the western side will increase that area by approximately 0.14 ha. This increase in area compared to the original extension plans will mostly comprise gravel so that water can infiltrate to ground. Any changes to the greenfield runoff rates due to this small increase in area will not measurably alter these estimates, and have there been carried forward for this assessment.

Table 5.1: Summary of Greenfield Runoff Rates (after MWH, 2013)

Return Period Greenfield Runoff Rate (l/s)

QBAR 2.8 Q (1yrs) 2.4 Q (30yrs) 4.9 Q (100yrs) 5.8 Q (200yrs) 6.5

Surface water runoff should be limited to the greenfield runoff rate, which will be confirmed as part of the detailed design of the drainage measures and is likely to be no greater than 2.8 l/s for the mean annual peak rate of runoff. On this basis, the risk to the Proposed Development from flooding, and the potential for the development to cause a change in the current flood risk, is considered to be low.

6.0 DRAINAGE STRATEGY

A drainage strategy for the original substation extension proposals was original presented in the 2013 Environmental Report. The content of that strategy was revisited as part of the addendum issued in 2016 when the proposed substation extension design was originally intended to be modified through a non-material variation and it was not deemed necessary to alter the proposed approach as a result of the amendments to the original application for the substation extension. Therefore, this section presents the original drainage strategy for the Proposed Development.

No foul drainage is required as part of this proposal.

6.1 Construction Period

The construction of the proposed temporary compounds and proposed substation extension will result in disturbance and compaction of the original ground conditions, which will alter the baseline runoff and infiltration characteristics.

During construction, bund and drain features to intercept runoff and direct the water to settlement ponds before discharge back to ground downgradient of the Proposed Development within the same catchment. The CEMP (Construction Environment Management Plan) or Construction Phase Plan (CPP) will include processes for treating and discharging water that is intercepted and may contain contaminants from construction processes or vehicles. Treated water will be discharged to ground downgradient of the Proposed Development and within the same catchment.

Should the existing SUDS features around the existing substation be used as part of the construction drainage attenuation system, then removal of additional silt will need to occur as part of maintenance of these features to allow ongoing functionality.

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6.2 Operational Period

6.2.1 Substation Extension

The surface water drainage for the Proposed Development will mimic the existing drainage regime. To address the changes to surface runoff patterns that will result from the construction and continued presence of the Proposed Development, it is intended to extend the existing SUDS comprising a swale, a filter trench and a network of pipes. All discharge from the SUDS will be limited to greenfield runoff rates presented in Table 5.1. Attenuation volumes required to restrict runoff from a 200 year event to the 30 year runoff rate were calculated as part of the 2013 assessment and are presented in Table 6.1. The additional development proposed as part of the 2016 addendum will not change the results of these calculations significantly, so the calculations have not been repeated for this assessment.

Table 6.1: Attenuation Volume Required to Restrict Site Runoff from a 200 yr Event to the Greenfield Runoff Rate (after MWH, 2013)

Percentage of Impermeable Surface

Max (200yr event) Storage Volume limited to 30yr greenfield (m3)

Max (200yr event) Storage Volume limited to Qbar greenfield (m3)

100% impermeable 725 - 1159 913 - 1432 75% impermeable 486 - 778 611 - 967 50% impermeable 274 - 446 347 - 555 25% impermeable 106 - 175 133 - 121 10% impermeable 26 - 46 35 - 59 5% impermeable 8.3 - 17 12 - 22

In order to provide capacity for the increase in discharge through the culverts, the existing northern culvert will be increased in diameter, which will be confirmed as the detailed design stage, but is likely to be of the order of 500mm to 600 mm. A new second southern culvert will be added through which to discharge the water from the swale.

The SUDS design will include an extension to the existing swale that will follow the boundary of the extended bund around the proposed substation extension. This swale will direct surface water run-off around the development and through two culverts under the existing access track (one existing culvert at the northern end of the existing substation and one new culvert at the southern end). These culverts will discharge the redirected surface run-off to marshy grassland located to the east of the existing access track, which ultimately drains to the Tay Burn; thereby not changing the general run-off patterns in the areas.

An existing filter trench will also be extended around the perimeter of the proposed substation extension (i.e. inside the bund) and will intercept additional surface water flows generated from the earth bund towards the proposed substation. This trench will connect to the existing northern and existing southern culverts and discharge to the east.

There will be a very limited increase in run-off from within the proposed substation extension itself as most precipitation that falls directly on the new surfacing will be able to infiltrate to ground through the permeable surface/gravels. The gravel material will also provide some temporary storage of water to attenuate flows to the SUDS. Any water that does not infiltrate to ground will flow under gravity towards the eastern part of the proposed substation extension, before draining via the system of pipes and a catch pit that form part of the existing substation. Any overflow from the catch pit will be directed to the existing middle culvert, which discharges to the marshy grassland to the east of the existing access track.

The schematic showing the proposed SUDS design that was included in the 2013 assessment and remains unchanged is included in Appendix A.

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6.2.2 Internal Access Track

The internal access track that will be surfaced will be a 3 m long section of access track within the proposed substation extension boundary. Runoff from the surfaced track will be directed to the filter drain within the proposed substation compound.

6.3 Decommissioning Period

All barriers and drains used to manage runoff will be removed and ground levels reinstated once the proposed temporary compounds are no longer required. All temporary and permanent hardstanding areas will also be removed and the site reinstated to its initial condition (i.e. re-profiled to the original topography and soils replaced in order to create drainage similar to the pre-construction setting).

6.4 Consideration of Design Exceedance

The 2013 drainage strategy also considered the consequences of exceeding the 0.5 % annual probability storm and the routing of overland flows in an extreme rainfall event. In the event of a more extreme rainfall event (e.g. due to changes in climate), the swale and site drainage would reach capacity and overflow. However, the resultant effect of temporary standing water on some hardstanding areas was considered not to effect the operation of the proposed substation. Based on the existing drainage catchment and the topography surrounding the proposed substation extension, any overland flow generated in an extreme rainfall event will flow from west to east. The proposed levels and layout of the extended substation will preserve this overland flood route to the east in extreme rainfall events by flow around the site and through the SUDS. If runoff outside the perimeter bund exceeds the capacity of the swale drainage system, water will flow overland towards the east. If runoff within the perimeter bund exceeds the capacity of the filter trench it would initially be stored within the gravel base of the proposed substation extension before either infiltrating to ground or being discharge later through the SUDS. If the gravel were to become saturated, surface water would be discharged off-site to the east, over the existing access track, onto the marshy grassland and would drain towards the Tay Burn.

7.0 CATCHMENT HYDROLOGY ASSESSMENT

7.1 Assessment Method and Significance Criteria

Using the baseline conditions identified from the sources in the previous sections, and the description of the Proposed Development presented in Chapter 3 of the Environmental Report, the potential changes upon the hydrological environment resulting from the Proposed Development are described in this chapter. A qualitative assessment methodology is then used to assess the magnitude of the potential changes and the significance of the effects.

Two factors have been considered in using this approach: 1) the sensitivity of the receiving environment (in this case a watercourse, surface water body or surface water abstraction); and 2) the magnitude of the change should it occur. This approach provides a mechanism for identifying the areas where mitigation measures are required, and for identifying mitigation measures appropriate to the significance of the effects presented to the hydrological environment by the Proposed Development.

The sensitivity classification of the receiving environment is defined in Table 7.1. Criteria for determining the magnitude of the change are provided in Table 7.2. The sensitivity of the receiving environment together with the magnitude of the change defines the significance of the effect, as identified within Table 7.3. The discussion of each potential effect also defines if the effect is beneficial or adverse, permanent or temporary, and reversible or irreversible.

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Table 7.1: Sensitivity Criteria for Receptor

Sensitivity Definition

Very High International importance. Receptor with a high quality and rarity, regional or national scale and limited

potential for substitution/replacement.

High

National importance. Human Health. Receptor with a high quality, local scale and limited potential for substitution/

replacement; or Receptor with a medium quality and rarity, regional or national scale and limited

potential for substitution / replacement.

Medium

Regional importance. Receptor with a medium quality and rarity, local scale and limited potential for

substitution/replacement; or Receptor with a low quality and rarity, regional or national scale and limited

potential for substitution/replacement.

Low Local importance. Receptor with a low quality and rarity, local scale. Environmental equilibrium is stable and is resilient to changes that are greater

than natural fluctuations, without detriment to its present character.

Table 7.2: Magnitude of Change Criteria and Definitions

Magnitude Description of Criteria

Adverse Beneficial

High

Loss of resource/receptor, loss of quality and integrity of the resource/receptor, severe damage to key characteristics, features or elements.

Large scale or major improvement to resource/receptor quality, extensive restoration or enhancement.

Medium

Partial loss of resource/receptor, partial loss of quality and integrity of the resource/receptor, damage to key characteristics, features or elements.

Improvement to resource/receptor quality, some restoration or enhancement, addition of key characteristics, features or elements.

Low

Some measureable change in/damage to attributes, quality or vulnerability. Minor loss of, or alteration to, key characteristics, features or elements.

Minor benefit to, or addition of, one or more key characteristics, features or elements. Some beneficial impact on the attribute or reduction in the negative impact.

Very Low Very minor (immeasurable) change to one or more characteristics, features or elements.

Very minor (immeasurable) benefit to, or positive addition of, one or more characteristics, features or elements.

Negligible No change to characteristics, features or elements.

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Table 7.3: Significance of Effect

Receptor Sensitivity

Magnitude of Change

Negligible Very Low Low Medium High

Low None None Slight Slight Minor Medium None Slight Slight Minor Moderate

High None Slight Minor Moderate Major

Very High None Minor Moderate Major Major

The relative significance of effects presented in Table 7.3 can be described in the following terms:

Major - a fundamental change to the environment.

Moderate - a material but non-fundamental change to the environment.

Minor - a detectable but non-material change to the environment.

None - no detectable change to the environment.

Effects of ‘major’ and ‘moderate’ significance (bold in Table 7.3) are considered to be ‘significant’ in terms of this assessment and in terms of the Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011.

7.2 Receptor Classification

The key receptors considered as part of this assessment, and their assigned classification based on the criteria presented in Table 7.1 are presented in Table 7.4.

Table 7.4: Hydrology Receptors for Assessment of Effects

Receptor Reason Receptor Sensitivity

The Tay Burn

The Tay Burn feeds into the River Tweed SAC and SSSI. Changes to the flow into, flow in, or quality of, the Tay Burn could have knock-on effect to the quality of watercourses downstream. Changes to the geomorphology could affect flows, quality and the habitats dependent on these.

Very High (headwater of river with international and national importance)

Groundwater in the Gala Group

Groundwater is likely to provide some baseflow to the Tay Burn. The Proposed Development is in a protected drinking water area, but the likelihood of groundwater being used directly as a water supply at locations close to the site is limited due to the low productivity status of the aquifer.

Medium (potential drinking water resource with good chemical status, but likely low productivity aquifer, that provides baseflow to the Tay Burn)

The Proposed Development

Consideration of risks from flooding to the Proposed Development.

Medium (regional distribution of electricity)

7.3 Design Mitigation

A CEMP/CPP will be prepared in advance of construction and be informed by relevant good practice included in “Good practice during windfarm construction” (SNH, 2015). The CEMP/CPP will include details of good practice and management methods that will be used to manage surface water runoff, suspended sediments, and the actions that will be followed to limit the potential for fuel leaks/spills and the processes that will be followed if leaks/spills do occur.

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Key elements of good practice that will be incorporated into the CEMP/CPP, and design details that are relevant to the protection of hydrology, will include, but not be limited to, the following:

There will be no construction in, or within 50 m of, surface watercourses. This “stand-off” distance will be finalised with SEPA before construction commences.

Pollution management measures will be implemented to prevent surface water and groundwater contamination by machinery pollutants, such as fuels, oils and lubricants during construction, operation and decommissioning activities. These measures will be informed by guidance provided in the relevant SEPA PPGs, which may include

PPG 1 General guide to the prevention of pollution;

PPG 2 Above ground oil storage;

PPG 5 Works and maintenance in or near water;

PPG 6 Working at construction and demolition sites;

PPG 8 Safe storage and disposal of used oils;

PPG13 Vehicle washing and cleaning;

PPG 21 Pollution incident response planning;

PPG 22 Incident response - dealing with spills; and

PPG 26 Safe storage - drums and intermediate bulk containers.

During construction, bund and drain features will be designed to intercept runoff and direct the water to settlement ponds before discharge back to ground downgradient of the Proposed Development within the same catchment. The CEMP/CPP will include processes for treating and discharging water that is intercepted and may contain contaminants from construction processes or vehicles should other control measures not avoid this. Treated water will be discharged back to ground downgradient of the Proposed Development within the same catchment.

Debris from construction, operation and/or decommissioning activities will be prevented from entering watercourses and removed immediately should this occur.

Topsoils will be stored for reuse. Where stored soil or exposed soils could wash into watercourses or wetland areas, temporary silt traps and/or fences will be used.

Any barriers to surface flow used during the construction period only will be removed and ground levels reinstated.

SEPA will be consulted to determine if the water management features and discharges required authorisation under the Water Environment (Controlled Activities) (Scotland) Regulations. If authorisation is required, the developers will make the relevant application(s).

As part of the design of the operational development, the following measures will be put in place:

Areas of hardstanding will be kept to a minimum and most of the proposed surfaces will comprise a compacted granular material that is inherently permeable. This will allow precipitation to infiltrate to ground rather than adding to runoff.

No buildings are proposed as part of the works.

Bunds or drains will be employed on the upstream end of the site boundary, in areas of relatively steep topography, to prevent surface waters from reaching the site. Runoff at the proposed substation extension will be attenuated by extensions to the existing SUDS, and discharges will be attenuated to greenfield runoff rates. Settlement and treatment (if required) will take place before discharge to the downstream catchment.

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During decommissioning, the above ground infrastructure and impermeable hardstanding will be removed. The site will then be reinstated to as close to pre-development conditions as possible. An Environment Management Plan will be prepared and adhered to for the decommissioning works.

7.4 Assessment of Initial Effects

This section considers the potential changes that could occur to the key receptors as a result of the Proposed Development. Each change is discussed and a magnitude assigned to it using the criteria in Table 7.2 before the significance of the effect is assigned using the matrix presented in Table 7.3.

The initial assessment of potential effects takes into account the design mitigation (i.e. the control measures and good practice in the CEMP/CPP, and the drainage strategy) as they will form part of the inherent design of the Proposed Development and the development would not occur without them being in place.

Where necessary, additional mitigation is recommended and an assessment of residual effects has been made. A summary of the changes considered and the associated effects is presented in Section 7.7.

7.4.1 Construction

The activities that are considered in this stage are as follows:

The construction and use of the proposed temporary compounds;

The construction of perimeter bunding;

The extension of the existing SUDS (including the addition of new culverts); and

The construction of the proposed substation extension (including earthworks, fencing, installation of the electrical equipment, and the construction of the surfaced internal access road).

In relation to the hydrological environment, the following changes are considered possible as a result of these activities:

Changes in quality of the runoff towards the Tay Burn – increased suspended solids or input of other pollutants (e.g. oils, lubricants and chemicals from machinery and construction activities) could disturb the river habitat by introducing silt and sediment and smothering gravel beds, changing erosion/deposition processes, increasing the suspended solids in the water column, and introducing pollution. The design mitigation includes silt traps, settlement ponds and pollution prevention measures. Taking these measure into account, the magnitude of change is predicted to be very low adverse. The associated effect on the very high sensitivity receptor is determined as ‘minor’ adverse, temporary and reversible.

Changes in the quality of water infiltrating to groundwater – oils, lubricants and chemicals from machinery and construction activities could introduce pollution to water recharging to ground. The design mitigation includes pollution prevention measures and the CEMP/CPP will include details regarding how machinery will be inspected and maintained, and how to deal with accidental leaks/spills. Taking these measures into account, the magnitude of change is predicted to be very low adverse. The associated effect on the medium sensitivity receptor is determined as ‘slight’ adverse, temporary and reversible.

Changes to runoff quantity (specifically changes to runoff towards the Tay Burn) – increased areas of compacted ground could increase and the temporary features could divert flow away from its natural path. Runoff from proposed temporary compound areas will be captured using temporary features (and potentially the existing SUDS) that will then discharge to ground to the east of the Proposed Development where it will have the chance to infiltrate to ground or flow over ground and ultimately to the Tay Burn. Discharge of intercepted runoff will be manged to greenfield rates. Taking these measure into account, the magnitude of change is predicted to be negligible. The associated effect on the very high sensitivity receptor is determined as ‘none’.

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Changes in flood risk due to changes in runoff (Secondary effect) - increased runoff into the Tay Burn and changes in sediment deposition during construction could result in change in flood risk at the Tay Burn. Discharge of intercepted runoff will be manged to greenfield rates, so there will be no change to flood risk at the Tay Burn. There is currently no flood risk at the site and it is unlikely that such changes would alter that. Taking these findings and measures into account, the magnitude of change is predicted to be negligible. The associated effect on the very high sensitivity receptor is determined as ‘none’.

All of the above changes have been assessed as resulting in either slight or minor effects. Therefore, none of the above predicted construction effects are considered ‘significant’ in terms of this assessment.

7.4.2 Operation

The only activities that will take place during operation related to ongoing inspection and maintenance of the proposed substation. It is assumed for this stage that the proposed temporary compounds have been decommissioned as per Section 7.4.3.

In relation to the hydrological environment, the following changes are considered possible as a result of the operational activities:

Changes in recharge to groundwater – recharge to the groundwater aquifer could be reduced by an increase in hardstanding. The potential for this reduction will be limited by the deign incorporating a high proportion of permeable surfacing. Taking these measure into account, the magnitude of change is predicted to be negligible. The associated effect on the medium sensitivity receptor is determined as ‘none’.

Changes to surface water quantity (specifically changes to runoff towards the Tay Burn) – The drainage strategy will result in either diverting water from upgradient around the site before discharging it to the east, or managing precipitation falling within the development and subsequently discharging it to the east. There is no proposed consumptive intervening use of that water. Multiple points of discharge to land to east helps reduce the effect of a point discharge of water collected though the SUDS. Hardstanding is limited and most of the developed area will have a permeable surface to reduce the potential for increases in surface run-off. Discharge of intercepted runoff will be managed to greenfield rates. Taking these measure into account, the magnitude of change is predicted to be negligible. The associated effect on the very high sensitivity receptor is determined as ‘none’.

Changes to surface water quality due to accidental leaks/spills – operational management of the site will include regular inspection routines (to limit the potential for accidental releases from substation equipment and maintenance vehicles) and pollution prevention measures (to address any accidental releases that might occur). Such mitigation is predicted to result in a negligible change to surface water quality. The associated effect on the very high sensitivity receptor is determined as ‘none’.

Changes to groundwater quality due to accidental leaks/spills – operational management of the site will include regular inspection routines (to limit the potential for accidental releases from substation equipment and maintenance vehicles) and pollution prevention measures (to address any accidental releases that might occur). Such mitigation is predicted to result in a negligible change to groundwater quality. The associated effect on the medium sensitivity receptor is determined as ‘none’.

Changes in flood risk due to changes in runoff (Secondary effect) - increased runoff into the Tay Burn and changes in sediment deposition due to the ongoing presence of the development and its drainage system could result in change in flood risk at the Tay Burn. Discharge of intercepted runoff will be manged to greenfield rates, so there should be no change to flood risk at the Tay Burn. There is currently no flood risk at the site and it is unlikely that such changes would alter that. Taking these findings and measures into account, the magnitude of change is predicted to be negligible. The associated effect on the very high sensitivity receptor is determined as ‘none’.

All of the above changes have been assessed as resulting in an effect significance categorised as none. Therefore, none of the above predicted construction effects are considered ‘significant’ in terms of this assessment.

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7.4.3 Decommissioning

It is assumed decommissioning will take place in phases as elements of the Proposed Development are progressively no longer required. There will be some decommissioning of the proposed temporary compounds after construction is complete. It is not known when decommissioning of the proposed substation will occur, but it is assumed it will take place at some time in the future.

In relation to the hydrological environment, the following changes are considered possible as a result of any of the decommissioning activities:

Changes in quality of the runoff towards the Tay Burn – increased suspended solids or input of other pollutants (e.g. oils, lubricants and chemicals from machinery and construction activities) during decommissioning activities could (as with construction) disturb the river habitat by introducing silt and sediment and smothering gravel beds, changing erosion/deposition processes, increasing the suspended solids in the water column, and introducing pollution. The mitigation included in the decommissioning plan will be similar to those adopted during construction (e.g. silt traps, settlement ponds and pollution prevention measures). Taking these measure into account, the magnitude of change is predicted to be very low adverse. The associated effect on the very high sensitivity receptor is determined as ‘minor’ adverse, temporary and reversible.

Changes in the quality of water infiltrating to groundwater – as with construction activities, there is the potential that oils, lubricants and chemicals from machinery and decommissioning activities could introduce pollution to water recharging to ground. The mitigation included in the decommissioning plan will be similar to those adopted during construction (e.g. pollution prevention measures, details regarding how machinery will be inspected and maintained, and how to deal with accidental leaks/spills). Taking these measures into account, the magnitude of change is predicted to be very low adverse. The associated effect on the medium sensitivity receptor is determined as ‘slight’ adverse, temporary and reversible.

Changes to surface water quantity (specifically changes to runoff towards the Tay Burn) – during decommissioning, the above ground infrastructure, impermeable hardstanding and drainage systems will be removed. The area will then be reinstated to as close to pre-development conditions as possible. Therefore, the intention is that runoff will return to near natural conditions and the changes are, therefore, classified as negligible when compared to baseline conditions. The associated effect on the very high sensitivity receptor is determined as ‘none’.

Changes in recharge to groundwater – during decommissioning, the above ground infrastructure and impermeable hardstanding will be removed. The area will then be reinstated to as close to pre-development conditions as possible. Therefore, the intention is that recharge rates will return to near natural conditions and the changes are, therefore, classified as negligible when compared to baseline conditions. The associated effect on the medium sensitivity receptor is determined as ‘none’.

Changes in flood risk due to changes in runoff (Secondary effect) – changes in runoff into the Tay Burn and changes in sediment deposition due to decommissioning activities could result in change in flood risk at the Tay Burn. During decommissioning, the above ground infrastructure, impermeable hardstanding and drainage systems will be removed. The area will then be reinstated to as close to pre-development conditions as possible. There is currently no flood risk at the site and it is unlikely that such changes would alter that. Therefore, the intention is that runoff will return to near natural conditions. Therefore, the change is classified as negligible when compared to baseline conditions. The associated effect on the very high sensitivity receptor is determined as ‘none’.

All of the above changes have been assessed as resulting in an effect significance categorised as none, slight or minor. Therefore, none of the above predicted construction effects are considered ‘significant’ in terms of this assessment.

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7.5 Additional Mitigation Measures

The initial assessment of potential changes indicates that the initial effects are not classified as significant. No additional mitigation is advised to reduce these effects further. The following additional details in relation to the mitigation are recommended to support the results of the initial assessment, but do not change the findings:

Methods for appropriate storage and reuse of soils should be agreed in advance with SNH – this may include covering stockpiles to limit erosion.

Appropriate long-term maintenance arrangements and plans should be put in place to make sure the SUDS and drainage systems at the development are managed in a way that means the interception and discharge of run-off and precipitation occurs in the intended way.

Methods for the reinstatement of near-original ground conditions should be discussed and agreed with the appropriate statutory body (e.g. SNH, SEPA) as part of the preparation of decommissioning plans.

7.6 Assessment of Residual Effects

No additional mitigation is required to reduce the initial effects, so no further assessment has been made. The results of the assessment of initial effects remain valid.

7.7 Summary of Effects

Table 7.5 presents a summary of the changes considered in this assessment, the inherent design mitigation and additional mitigation, and the residual effect significance.

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Table 7.5: Summary of Effects

Project Phase

Receptor Sensitivity Description of Change (Pre-mitigation)

Level of Effect (Pre-mitigation)

Mitigation Measures Magnitude of Change (Post-mitigation)

Residual Effect Significance

Nature of Effect

Beneficial/

Adverse

Permanent/

Temporary

Reversible/

Irreversible

Con

stru

ctio

n

Tay Burn (Quality) Very High

Changes in quality of the runoff due to increased suspended solids or input of other pollutants

Minor

Methods for appropriate storage and reuse of soils should be agreed in advance with SNH.

Very Low Minor Adverse Temporary Reversible

Groundwater (Gala Group) Medium

Changes in quality of recharge due to pollutants from machinery and construction activities

Slight No additional measures Very Low Slight Adverse Temporary Reversible

Tay Burn (Flows) Very High

Changes to runoff quantity due to changes in the drainage regime

None No additional measures Negligible None n/a n/a n/a

Tay Burn (Flood Risk) Very High Changes in flood risk due to

changes in runoff None No additional measures Negligible None n/a n/a n/a

Ope

ratio

n

Groundwater (Gala Group) Medium Changes in recharge rates due

to increased hardstanding None No additional measures Negligible None n/a n/a n/a

Tay Burn (Flows) Very High

Changes to runoff quantity due to changes in the drainage regime

None Long-term maintenance of drainage systems Negligible None n/a n/a n/a

Tay Burn (Quality) Very High

Changes to surface water quality due to accidental leaks/spills

None No additional measures Negligible None n/a n/a n/a

Groundwater (Gala Group) Medium Changes to water quality due

to accidental leaks/spills None No additional measures Negligible None n/a n/a n/a

Tay Burn (Flood Risk) Very High Changes in flood risk due to

changes in runoff None Long-term maintenance of drainage systems Negligible None n/a n/a n/a

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Project Phase

Receptor Sensitivity Description of Change (Pre-mitigation)

Level of Effect (Pre-mitigation)

Mitigation Measures Magnitude of Change (Post-mitigation)

Residual Effect Significance

Nature of Effect

Beneficial/

Adverse

Permanent/

Temporary

Reversible/

Irreversible

Dec

omm

issi

onin

g

Tay Burn (Quality) Very High

Changes in quality of the runoff due to increased suspended solids or input of other pollutants

Minor No additional measures Very Low Minor Adverse Temporary Reversible

Groundwater (Gala Group) Medium

Changes in quality of recharge due to pollutants from machinery and construction activities

Slight No additional measures Very Low Slight Adverse Temporary Reversible

Tay Burn (Flows) Very High

Changes in runoff rates due to changes in hardstanding and drainage arrangements

None

Methods for reinstatement of ground conditions agreed as part of the preparation of decommissioning plans

Negligible None n/a n/a n/a

Groundwater (Gala Group) Medium Changes in recharge rates due

to changes in hardstanding None

Methods for reinstatement of ground conditions agreed as part of the preparation of decommissioning plans

Negligible None n/a n/a n/a

Tay Burn (Flood Risk) Very High Changes in flood risk due to

changes in runoff None

Methods for reinstatement of ground conditions agreed as part of the preparation of decommissioning plans

Negligible None n/a n/a n/a

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7.8 Cumulative Effects

No assessment of cumulative effects was undertaken in relation to hydrology in the 2013 assessment. Through design, good practice construction methods and appropriate mitigation, all of the potential effects as a result of the Proposed Development have been assessed as not being significant. Therefore, no assessment of cumulative effects has been included within this assessment.

8.0 REFERENCES

British Geological Survey (BGS) Geology Mapping. http://mapapps2.bgs.ac.uk/geoindex/home.html, accessed 17 February 2017.

Scottish Environment Protection Agency (SEPA) Flood Risk Management Strategy: Tweed Local Plan District, version 1.1 dated February 2016.

Scottish Environment Protection Agency (SEPA) Flood Risk Mapping. http://map.sepa.org.uk/floodmap/map.htm, accessed 16 February 2017.

Scottish Environment Protection Agency (SEPA) River Basin Management Plan Mapping. http://gis.sepa.org.uk/rbmp/, accessed 17 February 2017.

Scottish Natural Heritage. Designated Site Mapping. http://gateway.snh.gov.uk/sitelink/searchmap.jsp, accessed 17 February 2017.

Scottish Power Transmission, 2013: Crystal Rig Substation Extension Environmental Report, prepared by MWH UK Ltd on behalf of Scottish Power Transmission. Version 02 dated 11 September 2013.

Scottish Power Energy Networks, 2016: Crystal Rig Substation Extension Environmental Report Addendum, prepared by Environmental Designworks for Scottish Power Energy Networks. Final Version dated April 2016.

Scotland’s Soils. 1:250,000 National Soil Map of Scotland. http://www.soils-scotland.gov.uk/data/soil-survey, accessed 17 February 2017.

9.0 GLOSSARY

Attenuation – to reduce the effect of something.

Aquifer - a body rock that contains or transmits groundwater and releases it in sufficient quantities for use.

Baseflow - the portion of flow in a surface watercourse that comes from the input from deep subsurface flow and delayed shallow subsurface flow.

Bedrock – Bedrock Geology (formally known as solid geology) is the solid rock that is either exposed at the surface or located beneath superficial material such as soils and gravels.

Bund - an embankment typically constructed from earth or stone.

Catchment – the area of land, usually delineated by topography, over which all precipitation that falls ends up in specific waterbody. Also referred to as a drainage basin.

CEMP (Construction Environment Management Plan) – document that defines how a project will be managed to meet environmental objectives. Details the targets, objectives and procedures that will be adopted.

CPP (Construction Phase Plan) – see CEMP.

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Gley – widespread throughout Scotland, a gley is a sticky soil that developed under conditions of intermittent or permanent waterlogging. They tend to be greyish or bluey-grey in colour with orange mottling. The colour is a result of the low levels of oxygen present during their formation.

Greenfield - denoting the state prior to development.

Precipitation - rain, snow, sleet, or hail that falls to or condenses on the ground.

Receptor - something that could be adversely affected by a change to its environment.

Settlement Pond – also commonly referred to as a settling basin. An open feature used to manage pollution and runoff from earth works. Used to allow settlement of suspended solids before slowly releasing discharge at the desired rate.

Silt Fence - a temporary sediment management device made of a porous fabric attached to posts in the ground and used on construction sites to protect water quality in nearby watercourses/waterbodies.

Soakaway - a pit, typically filled with permeable material, into which waste water is piped so that it drains slowly out into the surrounding soil.

SUDS (Sustainable Urban Drainage System) - provide a natural approach to managing drainage in and around developments and aim to prevent water pollution and flooding. Techniques include green roofs, permeable surfaces, infiltration trenches, swales, wetlands and water detention basins.

Superficial Deposits - Superficial deposits (formerly known as 'drift') are the youngest geological deposits formed during the most recent period of geological time (the Quaternary). Most superficial deposits are unconsolidated (loose, not cemented) sediments such as gravel, sand, silt and clay.

Swale – a shallow drainage channels in the ground where water running off a site can be channelled to another location or collect and soak away.

Topsoil – the top layer of soil; commonly fertile and dark coloured surface soil where plants root themselves.

Wacke – an impure sandstone comprising poorly sorted mineral and rock fragments in a finer silt and clay matrix.

Water assets - Scottish Water’s assets, including pipelines, treatment works and reservoirs.

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Report Signature Page

GOLDER ASSOCIATES (UK) LTD

Anna Goodwin Matt Goode Project Manager Reviewer

AG/MG/kc

Company Registered in England No.1125149. At Attenborough House, Browns Lane Business Park, Stanton-on-the-Wolds, Nottinghamshire NG12 5BL VAT No. 209 0084 92 Golder, Golder Associates and the GA globe design are trademarks of Golder Associates Corporation.

FLOOD RISK STATEMENT, DRAINAGE STRATEGY AND CATCHMENT HYDROLOGY ASSESSMENT

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PROJECTCRYSTAL RIG SUB-STATION EXTENSION - FLOOD RISKSTATEMENT, DRAINAGE STRATEGY AND CATCHMENTTITLEHYDROLOGY AND AUTHORISED LOCATIONS

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APPENDIX A 2013 Crystal Rig Substation Extension Environmental Report - Figure 10.4 Proposed Drainage Arrangements

Crystal Rig Substation Extension ScottishPower TransmissionEnvironmental Report

Figure 10.4 Proposed Drainage Arrangements

MWH UK LTD Page 116 of 140 RR-ED-2178.0241520391 September 2013

Golder Associates (UK) Ltd

Sirius Building, The Clocktower

South Gyle Crescent

Edinburgh

EH12 9LB

UK

T: [+44] (0) 131 314 5900

Caption Text

T e c h n i c a l A p p e n d i x 7 . 0 : D r a f t M i t i g a t i o n M e a s u r e s This Appendix identifies a preliminary draft of actions that SPEN shall implement to reduce, offset, prevent or compensate for identified potential adverse effects on the environment that may otherwise result as a consequence of proposed development of the Crystal Rig Substation Extension. Draft Schedule of Mitigation Measures No. Draft Schedule of Mitigation Measures General 1 Construction

Environmental Management Plan & Pollution Prevention Plan

All mitigation measures as outlined in this Environmental Report and any planning consent conditions will be detailed and implemented by a Construction Environmental Management Plan (CEMP) and Pollution Prevention Plan (PPG) prepared specifically for the proposed Crystal Rig Substation Extension. These documents shall control and guide the working practices of the Contractor for the duration of the construction works and shall reflect current best practice and guidance in protecting the environment.

2 SWMP A Site Waste Management Plan shall detail the requirements for management of any waste in accordance with statutory and licencing requirements, accepted good practice and to ensure that wherever possible materials are reduced, reused or recycled in preference to disposal. This will include toilet facilities, soils/ stone/ peat from excavations, concrete from washout areas, municipal type wastes etc

Agricultural Land 3 CEMP On Site Construction Works. Reinstatement agreed with landowner and works

undertaken in accordance with CEMP.

Air Quality 4 CEMP/PPG Control measures shall be put in place in accordance with the CEMP and PPG.

Noise and Vibration 5 CEMP/PPG Control measures shall be put in place in accordance with the CEMP and PPG.

Socio Economic & Community Effects 6 CEMP Control measures shall be put in place in accordance with the CEMP and PPG.

Traffic and Transport 7 Traffic

Management Plan

A Traffic Management Plan shall be prepared and include all information as requested by the Council and indicate agreed transport route, management measures and programme for restoration etc. In accordance with the current planning permission conditions a Dilapidation Survey and Road Repairs and Swept Path Analysis shall be undertaken in accordance with the Council requirements. In addition any planning consent conditions required by the Council shall be undertaken.