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Waverley Railway (Scotland)

An Assessment of the Effects to The River Tweed Special Area of Conservation VOLUME 1 November 2005 www.erm.com

Waverley Railway (Scotland): An Assessment of the Effects to The River Tweed Special Area of Conservation

November 2005

Reference 0000232

This report has been prepared by Environmental Resources Management the trading name of Environmental Resources Management Limited, with all reasonable skill, care and diligence within the terms of the Contract with the client, incorporating our General Terms and Conditions of Business and taking account of the resources devoted to it by agreement with the client. We disclaim any responsibility to the client and others in respect of any matters outside the scope of the above. This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party relies on the report at their own risk.

For and on behalf of Environmental Resources Management Approved by: Steve Purnell

Signed: Position: Partner Date: 28th November 2005

CONTENTS

VOLUME 1

1 INTRODUCTION 1-1

1.1 BACKGROUND AND AIM OF THE REPORT 1-1 1.2 APPROPRIATE ASSESSMENT PROCESS 1-1 1.3 REPORT STRUCTURE 1-5

2 RIVER TWEED SPECIAL AREA OF CONSERVATION 2-1

2.1 DESIGNATION AND FEATURES OF INTEREST 2-1 2.2 CONSERVATION OBJECTIVES 2-1 2.3 PUBLISHED INFORMATION 2-3 2.4 SURVEY REQUIREMENTS 2-4

3 THE PROPOSED SCHEME 3-1

3.1 OVERVIEW 3-1 3.2 ENGINEERING WORKS 3-2 3.3 OPERATION 3-22

4 BASELINE SURVEYS 4-1

4.1 SURVEY SCOPE 4-1 4.2 METHODOLOGY 4-1 4.3 SURVEY FINDINGS 4-10

5 IMPACT ASSESSMENT 5-1

5.1 INTRODUCTION 5-1 5.2 ASSESSMENT METHODOLOGY 5-1 5.3 POTENTIAL IMPACTS 5-2 5.4 SENSITIVITY ASSESSMENT 5-3 5.5 MITIGATION MEASURES 5-10 5.6 RESIDUAL IMPACTS 5-13

6 CONSIDERATION OF IN-COMBINATION EFFECTS 6-1

6.1 INTRODUCTION 6-1 6.2 OBJECTIVES OF THE STUDY 6-1 6.3 SCOPE OF STUDY 6-1 6.4 LIMITATIONS AND UNCERTAINTY 6-2

6.5 REVIEW OF PLANS AND PROGRAMMES 6-3 6.6 PLANNING APPLICATION REVIEW 6-6 6.7 DISCUSSION OF IN-COMBINATION EFFECTS 6-6

7 MONITORING 7-1

7.1 OVERVIEW AND OBJECTIVES 7-1 7.2 PRE-CONSTRUCTION MONITORING 7-1 7.3 CONSTRUCTION MONITORING 7-2 7.4 POST-CONSTRUCTION MONITORING 7-2 7.5 LONG TERM POST-CONSTRUCTION MONITORING 7-3

8. SUMMARY 8-1

ANNEX A RIVER TWEED SAC ANNEX B ENGINEERING PROCESSES ANNEX C SCOTT WILSON ENGINEERING REPORT ANNEX D HYDROLOGY AND WATER QUALITY REVIEW ANNEX E RIVER HABITAT SURVEY FORMS ANNEX F TERRESTRIAL VEGETATION BASELINE REPORT ANNEX G MACROPHYTE BASELINE REPORT

VOLUME 2

ANNEX H OTTER BASELINE REPORT ANNEX I SALMON BASELINE REPORT ANNEX J LAMPREY BASELINE REPORT ANNEX K ASSESSMENT PROFORMA ANNEX L IMPLICATIONS OF ENGINEERING WORK FOR LONG TERM HABITAT POTENTIAL ANNEX M CODE OF CONSTRUCTION PRACTICE ANNEX N IN-COMBINATION ASSESSMENT

ENVIRONMENTAL RESOURCES MANAGEMENT WAVERLEY RAILWAY PROJECT

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1 INTRODUCTION

1.1 BACKGROUND AND AIM OF THE REPORT

Scottish Borders Council ‘The Promoter’ proposes to redevelop the Waverley Railway line between Newcraighall on the outskirts of Edinburgh and Tweedbank near Galashiels in the Scottish Borders. The route is approximately 48 km in length (see Figure 1.1) and is located generally on the former Waverley Railway line. An Environmental Statement (ES) was submitted in September 2003 in support of the Waverley Railway (Scotland) Bill introduced in the Scottish Parliament in September 2003. The proposed railway line closely follows the route of the Gala Water (a tributary of the River Tweed) for approximately 30 km between Heriot and Galashiels (see Figure 1.2). The River Tweed (and its tributaries) is designated as a Special Area of Conservation (SAC) for habitats of European importance that it supports. SACs are part of the network of Natura 2000 sites set up under the EU Habitats Directive 1992 (1). In the UK, the Directive has been transposed into national law by means of the Conservation (Natural Habitats, & c.) Regulations 1994 (as amended); these are known as the Habitats Regulations. The key aim of this document is to provide sufficient information upon which a decision can be made with regard to impacts of the Waverley Railway (Scotland) Bill in the context of the Habitats Regulations. It therefore focuses on the potential for impacts to the qualifying species for which the River Tweed SAC has been designated, and reports the predicted impacts on them from the scheme and in-combination with other projects.

1.2 APPROPRIATE ASSESSMENT PROCESS

Under the Habitats Regulations, if a development is proposed within or in close proximity to a Natura 2000 site, the Competent Authority, in this case the Scottish Parliament, must undertake an assessment to satisfy themselves that there will be no impacts (following mitigation) that could adversely affect the integrity of the qualifying interests (2) for which the site is designated. This is known as an Appropriate Assessment. If the impacts are predicted to adversely affect the integrity of the qualifying interest, it must be demonstrated that there are special reasons why the development should be permitted to proceed.

(1) Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora. (2) A natural or semi-natural feature for which a European site has been selected. This includes any Habitats Directive

Annex i habitat or Annex II species and any population of a bird species for which the site has been selected under the Birds Directive.


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Figure 1.1 Location Plan – Proposed Waverley Railway between Edinburgh and Tweedbank near Galashiels


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Figure 1.2 The Proposed Waverley Railway and the Gala Water

The integrity of the site is defined as “the coherence of its structure and function, across its whole area, that enables it to sustain the habitat, complex of habitats and/or the levels of populations of the species for which it was classified” (1). An adverse effect on site integrity can be described as any effect that may reasonably be predicted as a consequence of a plan or project that may affect the

(1) Scottish Executive RAD 2000, Revised Guidance updating Scottish Office Circular 6/95


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conservation objectives (1) of the qualifying interests for which the site has been designated. Scottish Natural Heritage (SNH) guidance (2) records the fact that Appropriate Assessment is different from formal Environmental Impact Assessment (EIA). SNH’s role in the Appropriate Assessment process is to advise the competent authority in making this decision. The guidance indicates that the onus is on the competent authority to provide sufficient information to satisfy SNH’s concerns. The guidance describes a staged process for undertaking such assessments as follows: 1. define the proposal; 2. establish that it is not necessary to management of the site for nature

conservation purposes (in which case no further assessment would be required);

3. determine whether the proposal is likely to have a significant effect on

the site. This acts as a coarse sieve to remove from the process projects which are neutral, trivial, or very short term in their impacts on a site’s qualifying interests;

4. if it cannot be demonstrated that the effect is “trivial or inconsequential”,

assess the implications of the development for the site’s conservation objectives so as to answer the question “can it be demonstrated that the proposal will not adversely affect the integrity of the site?” This is referred to as the Appropriate Assessment; and

5. if the assessment indicates that no adverse effect will occur, consent may

be granted; if not, further steps are required to demonstrate that specific reasons why the development should be permitted apply, before consent may be granted.

The proposals included in the Waverley Railway (Scotland) Bill are within and in close proximity to the River Tweed SAC, are not necessary to the management of the site for nature conservation and, based on the assessment provided in the ES, it has been determined that the proposals could have a significant effect. An Appropriate Assessment (Step 4 of SNH guidance) is therefore required, confirmed by SNH in their letter of 28 April 2004 to the Promoter.

(1) A statement of the nature conservation aspirations for a site, expressed in terms of the favourable condition required for the habitats and/or species for which the site has been selected.

(2) Scottish Natural Heritage Guidance note Series 2000: Natura Casework Guidance: Consideration of Proposals affecting SPA and SAC.


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As such, an appropriate Scope of Work was developed and agreed (during a series of workshops) with SNH, which includes the following: • description of the River Tweed SAC and interest features for which the site

was designated; • information on the proposed project, highlighting elements that may affect

the designated features of the River Tweed SAC; • surveys to establish the status and location of the qualifying interests in

relation to the scheme proposals; • identification and evaluation of potential impacts on the ecology and

nature conservation value of the site; and • the potential for in-combination effects when considered along with

existing and proposed schemes will be assessed.

1.3 REPORT STRUCTURE

The remainder of the report is structured as follows: Section 2 – River Tweed Special Area of Conservation

• Designation and features of interest • Conservation objectives • Published information • Survey requirements (cross refer to Sections 3 and 4)

Section 3 – The Proposed Scheme

• Overview • Engineering works (permanent and temporary works) • Operation

Section 4 – Baseline Surveys

• Survey Scope • Methodology • Survey Findings

Section 5 – Impact Assessment

• Introduction • Assessment Methodology • Potential Impacts • Sensitivity Assessment • Mitigation Measures • Residual Impacts

o Introduction o Assessment o Operational impacts


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o Cumulative and in-combination impacts • Summary

Section 6 – Consideration of In-Combination Effects

• Introduction • Objectives of the Study • Scope of Study • Limitations and Uncertainty • Review of Plans and Programmes • Planning Application Review • Discussion of in-combination effects

Section 7 – Monitoring

• Overview and Objectives • Pre-Construction Monitoring • Construction Monitoring • Post Construction Monitoring • Long Term Post-Construction Monitoring

Section 8 - Summary The above report Sections are supports by the following Annexes: • Annex A: River Tweed SAC; • Annex B: Engineering Processes; • Annex C: Scott Wilson Engineering Report; • Annex D: Hydrology and Water Quality Review; • Annex E: River Habitat Survey Forms; • Annex F: Terrestrial Vegetation Baseline Report; • Annex G: Macrophyte Baseline Report; • Annex H: Otter Baseline Report; • Annex I: Salmon Baseline Report; • Annex J: Lamprey Baseline Report; • Annex K: Assessment Proforma; • Annex L: Implications of engineering work for long term habitat potential; • Annex M: Code of Construction Practice; and • Annex N: In-Combination Assessment.


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2 RIVER TWEED SPECIAL AREA OF CONSERVATION

2.1 DESIGNATION AND FEATURES OF INTEREST

The River Tweed SAC includes the River Tweed and its tributaries which together extend to 3,795.88 hectares (ha) within the Scottish Borders and Northumberland (see Annex A). The site is comprised of a number of mainly wetland habitats: • tidal rivers, estuaries, mud flats, sand flats, lagoons (including salt water

basins), approximately 1% of the site area; • inland water bodies (standing water running water), approximately 96%

of the site area; • bogs, marshes, water fringed vegetation and fens, approximately 2% of the

site area; and • broad-leaved deciduous woodland, approximately 1% of the site area. The primary reasons for selection of the site as an SAC include the following: • aquatic plant communities (Ranunculion fluitantis and Callitricho-Batrachion

(CB)), listed in Annex I of the Habitats Directive; • Atlantic salmon (Salmo salar), listed in Annex II of the Habitats Directive;

and • otter (Lutra lutra) listed in Annex II of the Habitats Directive. Sea, brook and river lamprey (Lampetra fluviatilis, L.planeri and Petromyzon marinus) are also a qualifying species present, though not the primary reason for the selection of the site. The full citation for the site is included as Annex A.

2.2 CONSERVATION OBJECTIVES

2.2.1 Overview

SNH have conservation objectives for all the Natura 2000 sites in Scotland. Conservation objectives are set to ensure that the obligations of the Habitats Directive are met, particularly to ensure that there should be no deterioration or significant disturbance of the qualifying features from their condition at the


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time the Natura status of the site was formally identified (1). The conservation objectives are also essential in determining whether a plan or project is likely to have a significant effect (2). The conservation objectives for the River Tweed SAC are summarised below.

2.2.2 Objectives for the River Tweed SAC

Annex 1 Habitats Conservation Objectives

To avoid deterioration of the qualifying habitat, water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation, thus ensuring that the integrity of the site is maintained and the site makes an appropriate contribution to achieving favourable conservation status (FCS) (3) for each of the qualifying features. To ensure for the qualifying habitat that the following are maintained in the long term: • extent of the habitat on site; • distribution of the habitat within site; • structure and function of the habitat; • processes supporting the habitat; • distribution of typical species of the habitat; • viability of typical species as components of the habitat; and • no significant disturbance of typical species of the habitat. Annex II Species Conservation Objectives

To avoid deterioration of the habitats of the qualifying species (Atlantic salmon, otter, sea, brook and river lamprey) or significant disturbance to the qualifying species, thus ensuring that the integrity of the site is maintained and the site makes an appropriate contribution to achieving FCS for each of the qualifying features. To ensure for the qualifying species that the following are maintained in the long term: • population of the species (including range of genetic types where relevant)

as a viable component of the site; • distribution of the species within site; • distribution and extent of habitats supporting the species; (1) Scottish Natural Heritage (2004) Guidance for Competent Authorities when dealing with proposals affecting SAC freshwater sites. October. (2) Article 6.2 of the Habitats Directive. (3) Defined in Article 1 of the Habitats Directive can be used as a term of reference to fix the limit of acceptable disturbance

and deterioration with respect to the objectives of the directive and to determine if the appropriate measures are properly implemented.


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• structure, function and supporting processes of habitats supporting the species;

• no significant disturbance of the species; • distribution and viability of the species’ host species (where relevant); and • structure, function and supporting processes of habitats supporting the

species' host species (where relevant). The predicted impacts described in Section 5 are assessed against the conservation objectives for the site to help determine whether the proposals will adversely affect the integrity of the site.

2.3 PUBLISHED INFORMATION

There is already a considerable amount of published survey information on the River Tweed and its tributaries, particularly on the qualifying habitats and species of the SAC site. This information was reviewed to help scope the necessary further surveys (see Section 2.4 and Section 4). Published information reviewed included the following: • The Tweed Foundation Tweed Fish Species Database salmon monitoring

sites data for the Gala Water; • Integrated Fishery Management Plan for the Tweed Fishery District.

Tweed Foundation (May 1990); • Report on the Elecro-fishing Monitoring of the Larger Channels of the Quair,

Leithen, Caddon & Gala Water Catchments & the Ellwyn & Bowden Burns, Tweed Foundation (Summer 1997);

• Report on the Electro-fishing Survey of the Smaller Burns of the Gala Water

Catchment, Tweed Foundation (Summer 1997); • Integrated Fishery Management Plan for the Tweed Fishery District, Tweed

Foundation (May 1990); • National Survey of Otter Lutra lutra Distribution in Scotland 2003-2004,

Scottish Natural Heritage (2005); • Assessment of Lamprey Distribution and Abundance in the River Tweed SAC,

SNH; • River Tweed Macrophyte Survey Northern Ecological Services for SNH

(1998);


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• The Assessment of Lamprey Distribution and Abundance in the River Tweed Candidate Special Area of Conservation / Site of Special Scientific Interest. Report Commissioned by SNH from The Tweed Foundation (unpublished). Campbell, R.N.B. and P. Corson, 2004; and

• Extension to the River Tweed cSAC update on Proposals and Progress. Scottish

Natural Heritage (Unpublished). Panter, A. 2003.

2.4 SURVEY REQUIREMENTS

Following review of available survey information and details of the proposals (see Section 3) it was agreed, in consultation with SNH, that the following surveys were required to inform the assessment: • River Habitat Survey – to establish the physical characteristics of the river

and to scope the requirement for any more detailed survey work; • Riparian and bankside vegetation – an extended Phase 1 Habitat Survey (1)

to establish the habitat type and diversity of the bankside vegetation; • Macrophyte survey – to determine the diversity and abundance of

macrophytes in the Gala Water, including the Ranunculion fluitantis and Callitricho-Batrachion communities for which the site is designated;

• Otter – to locate otter holts in proximity to the proposed work areas; and • Lamprey – to determine the abundance and quality of lamprey habitat in

proximity to the proposed work areas. For the purposes of the Appropriate Assessment, it has been assumed that that where suitable salmon spawning and juvenile habitat exists within the Gala Water, it will be readily utilised by Atlantic salmon and thus a confirmatory electro-fishing campaign was not considered necessary. Instead, suitable habitat in the Gala Water was mapped. This approach was based on advice from the Tweed Foundation and the existing evidence that the Gala Water is a very productive recruitment tributary, and was agreed with SNH. The survey methods and results are presented in Section 4.

(1) Joint Nature Conservation Committee (1993) Handbook for Phase 1 Habitat Survey – A Technique for Environmental Audit, JNCC, Peterborough.


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3 THE PROPOSED SCHEME

3.1 OVERVIEW

The route of the former Waverly railway runs close to the Gala Water and its tributaries, with existing bridge structures providing crossings in some 30 location (18 on Gala Water and 12 on tributaries). Approximately 30 km of the route lies within the Gala Water catchment. The major bridge structures are across the Gala Water. These structures generally consist of masonry piers and abutments with wrought iron bridge beams/trusses or masonry arch structures, and wrought iron girders or timber beams supporting the timber decking. At several locations the structures comprise multiple spans, with the main span(s) accommodating the river flow in dry weather, and the additional spans accommodating flows during flood conditions. Bridge structures on minor tributaries/drains tend to be culvert sections formed largely from masonry/brick/walls, steel rail beams and timber decking. Scour protection of the piers and abutments generally takes the form of riprap (loose rock), sheet piling and concrete aprons extending out from the piers/abutments. Where the railway is in close proximity to the Gala Water, riprap is also used for river bank protection (RBP), sheet piling and masonry retaining walls at some higher risk locations. Engineering surveys and structural assessments have been conducted along the route through the Gala Water catchment. These surveys have identified the remedial engineering works required at specific locations to ensure that the railway will meet Network Rail’s standards for operational safety. For impact assessment purposes the remedial engineering works have been typed into nine engineering processes: • temporary in-river diversion works; • major substructure repairs; • minor substructure repairs; • scour protection renewal; • superstructure repairs ; • superstructure replacement; • river diversion; • culvert replacement; and • river bank protection works. These processes are presented in detail within Annex B. Each process consists of a description of works, engineering design options (as applicable), a construction method, an assessment of potential impacts and identification of mitigation measures. Each of these processes is summarised within the following sections together with the locations to which they are applicable.


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Scott Wilson Railways (SWR) are responsible for scheme design. The full Scott Wilson engineering report is presented in Annex C.

3.2 ENGINEERING WORKS

3.2.1 Temporary in-River Diversion Works

Temporary in-river diversion works will be required when the main engineering works are to take place below river level and require a dry, safe working environment within the river bed to be established prior to the in-river works commencing. Temporary diversion works are required at 17 of the bridgework sites (see list below) to allow apron repair and foundation/pier /abutment strengthening (see Section 3.2.2), where the river will be diverted under the new road at Heriot (see Section 3.2.3), and where bank protection works are required for the construction of concrete or gabion retaining walls (see Section 3.2.5). • Little Gala Underbridge (ID 10); • Crookstone Mill Underbridge (ID 13); • Hollowshank Underbridge (ID 14); • Bower Underbridge (ID 16); • Fountainhall Culvert Underbridge(ID 17); • Plenploth North Underbridge (ID 19); • Torquhan South Underbridge (ID 20); • Watherston Culvert Underbridge (ID 23); • Watherston Underbridge (ID 25); • Gala Bank Underbridge (ID 26); • Lugate Bridge Underbridge (ID 30); • Ferniehirst Water Underbridge (ID 31); • Whitlee Culvert Underbridge (ID 39); • Whin Water Underbridge (ID 40); • Torwoodlee Water Underbridge (ID 42); • Kilnknowe Underbridge (ID 46); and • Red Bridge Underbridge (ID 49). As the construction of cofferdams will create more in-river disturbance than bunding, especially more sediment generation, cofferdams will only be used at only two locations (Torwoodlee Water Underbridge (ID 42) and Red Bridge Underbridge (ID 49)) where they are integral to the design of concrete scour protection aprons, and form part of the permanent scour protection (see Section 3.2.5).


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Cofferdams and Bunds • Cofferdams are constructed by driving sheet piling into the river bed around the works

area using a piling rig in-river (for bridge works), or operating from the bank (for river bank protection works). There are minimum height requirements piling rigs and hence, in the case of bridgeworks, cofferdams can only be used for bridges with high clearance above the river bed.

• Bunds are formed by constructing a wall of sand/grout bags around abutments or piers to divert the river flow and will generally be placed by hand (see below).

• The cofferdam or bunds creates a safe zone around the work from which water is then pumped out. The remaining water flow in the river will be diverted around the temporary structure.

• The works will be constructed to form a 3-4m buffer around the bridge structure or bank and area directly affected during the installation and removal will be no more than 10m upstream and downstream of the cofferdam or bund.

Source: Scott Wilson General Solutions Report (Annex C)

3.2.2 Bridgeworks

Major Substructure Repairs

The main substructure works which are required include: • structural repairs and strengthening to substructure; and • foundation strengthening (sheet piling and grouting).


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Structural Repairs to Substructure • The works involve some levelling/excavation of river bed, cutting out affected areas of

masonry and replacing with sound material and re-pointing where necessary.

Source: Scott Wilson General Solutions Report (Annex C) Foundation Strengthening • This work involves excavations to level the bed in the vicinity of the pier/abutment area,

and construction of a sheet pile cofferdam around the foundation area. Grout is then pumped into the cofferdam to fill fractures in the existing foundations and the sheet piling is left in-situ.



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Major structural repairs to the substructure are required at the following 10 bridge locations (see also Figure 3.1): • Hollowshank Underbridge (ID 14); • Watherston Underbridge (ID 25); • Gala Bank Underbridge (ID 26); • Ferniehirst Water Underbridge (ID 31); • Whitelee Culvert Underbridge (ID 39); • Whin Water Underbridge (ID 40); • Torwoodlee Water Underbridge (ID 42); • Ryehaugh Water Underbridge (ID 45); • Kilnknowe Underbridge (ID 46); and • Red Bridge Underbridge (ID 49). Foundation strengthening is also required at Torwoodlee Water and Red Bridge. Temporary in-river diversion works are required at all of these locations except Ryehaugh Water, where the work required can be achieved using scaffolding placed on the existing concrete apron. Bunding will be the main type of diversion used, with cofferdams being used at only two locations in deeper water (Torwoodlee Water and Red Bridge). The area which will be directly affected by these works is that required for installation and removal of the bunds or cofferdams for the temporary works (see Section 3.2.1). All works will be undertaken within this area. At Ryehaugh there will be no disturbance of the in-river habitats. Major substructure works are expected to take up to nine weeks to complete in any one location allowing for: • 2 - 3 weeks for site establishment and preparation; • 4 - 6 weeks for engineering repair works; and • 1 - 2 week for removal of the equipment and tidying of the site.


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Figure 3.1 Locations of Proposed Engineering Works on the Gala Water (© Crown copyright. All rights reserved. Licence No. 100044822)

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Minor Substructure Repairs

Minor substructure repairs to some bridges to repair voids and cracks and re-point structures, and may include the removal of deteriorated masonry and replacement with new material. The re-pointing work will require removal of vegetation from the structures prior to the repair work commencing. Minor works are required to abutments, piers and wingwalls in all 28 bridge locations, although the extent of the work varies as follows (see also Figure 3.1): • crack/void repair and de-vegetation / re-pointing (9 locations):

• Little Gala Underbridge (ID 10); • Hollowshank Underbridge (ID 14); • Bower Underbridge (ID 16); • Watherston Culvert Underbridge (ID 25); • Bowshank North Underbridge (ID 33); • Bowshank South Underbridge (ID 34); • Harper’s Culvert Underbridge (ID 36); and • underbridges near Heriot (Location IDs 50 and 51).

• de-vegetation and re-pointing only (10 locations):

• Shoestanes Underbridge (Location ID 5); • Crookstone Mill Underbridge (ID 13); • Hollowshank Culvert Underbridge (ID 15); • Fountainhall Culvert Underbridge (ID 17); • Plenploth North Underbridge (ID 19); • Torquhan South Underbridge (ID 20); • Lugate Bridge Underbridge (ID 30); • Flood Relief Culvert Underbridge (ID 32); • Torwoodlee Flood Relief Culvert (ID 43); • Underbridge near Heriot (ID 52).

In-river diversion works are required at a number of these locations (see Section 3.2.1). The duration of the works will depend on their complexity. At a complex site where in-river diversion works are required to enable the work to be undertaken and there is also a need for scour protection (see section on Scour Protection Replacement), the work may take up to nine weeks as follows: • 1 - 2 weeks for site establishment and preparation; • 4 - 6 weeks for engineering repair works; and • 1 week for removal of the equipment and tidying of the site. Where scaffolding can be used and there is no requirement for scour protection, completion of the work is expected to be quicker, in the order of four to five weeks as follows:


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• 0.5 - 1 week for site establishment and preparation; • 2 - 3 weeks for engineering repair works; and • 0.5 week for removal of the equipment and tidying of the site. The minor substructure works are essentially to repair the existing structures and hence permanent landtake will be negligible. Temporary landtake will be required to allow the construction to proceed and it is anticipated that this will be restricted to the land required for in-river diversion works, scaffolding etc (see Section 3.2.1). Scour Protection Replacement

Scour protection is critical to protect the bridge substructures (ie abutments, piers and wingwalls) from the erosive forces of the river. Existing scour protection techniques used on structures in the Gala Water include both riprap placed upstream of the piers or abutments, and concrete ‘aprons’ installed around the bases of piers and abutments, which extend partially or fully across the bridge spans. All scour protection replacement works will require temporary in-river diversion works (see Section 3.2.1). Repairs to Existing Concrete Aprons and Riprap Replacement • Repairs to concrete scour aprons require some excavation of the river bed,

and cutting back of the existing concrete to ensure there is a suitable base for the new concrete. Grouting may also be undertaken to repair the face and underside of the concrete apron. Riprap is placed upstream of the apron to protect the leading edge from undercutting.


Riprap Placement • Riprap placement may be used as a scour protection method in isolation to

concrete aprons. The installation of riprap involves excavation of the river bed to a suitable depth, and placement of suitably graded rock (the riprap)


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in the area around the abutment/pier, followed by replacement of natural bed material as a surface layer.

Scott Wilson General Solutions Report (Annex C) Repairs to the existing concrete aprons and riprap are required at the following 10 locations: • Crookstone Mill Underbridge (Location ID 13); • Hollowshank Underbridge (ID 14); • Bower Underbridge (ID 16); • Fountainhall Culvert Underbridge (ID 17); • Plenploth North Underbridge (ID 19); • Torquhan South Underbridge (ID 20); • Lugate Bridge Underbridge (ID 30); • Whin Water Underbridge (ID 40); • Torwoodlee Water Underbridge (ID 42); and • Red Bridge Underbridge (ID 49). All of these locations require the installation of temporary in-river diversion works, predominantly in the form of bunds, with cofferdams at two locations (Torwoodlee Water (ID 42) and Red Bridge (ID 49)). Bunding may also be required during grouting activity. Riprap scour protection alone will be required at the following four bridge locations and at the river diversion near Heriot: • Little Gala Underbridge (Location ID 10); • Watherston Underbridge (ID 25); • Gala Bank Underbridge (ID 26); and • Whitelee Culvert Underbridge (ID 39).


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All of these locations will require temporary in-river diversion works, predominantly in the form of bunds (see Section 3.2.1). The existing scour protection at the remaining 13 locations has been assessed as structurally sound and hence no works are necessary. All the works proposed entail repairs to existing scour protection hence the permanent landtake for these works will be negligible. Areas affected by the construction works will largely be those required for the temporary in-river diversions (see Section 3.2.1). The duration of the works will depend on whether repair of the concrete apron is required. If so the work will take up to nine weeks as follows: • 1 - 2 weeks for site establishment and preparation; • 4 - 6 weeks for engineering repair works; and • 1 week for removal of the equipment and tidying of the site. If rip-rap alone is required the construction period will be shorter, approximately six weeks as follows: • 1 - 2 weeks for site establishment and preparation; • 2 - 3 weeks for engineering repair works; and • 1 week for removal of the equipment and tidying of the site. Superstructure Repairs and Replacement

Most of the bridge superstructures crossing the Gala Water consist of wrought iron girders and/or lattice trusses. Many of these structures require repairs as the structures have remained unused since the railway closed. These repairs generally include erection of scaffolding, sandblast cleaning operations, repainting, waterproofing or the replacement of the bridge deck. Most of the repair works to the superstructure can be conducted from the existing railway embankment and existing bridge structures, avoiding in-river access or works. In some cases, where scaffolding may be required it is possible that it could be founded in the river bed. Eighteen locations require repairs and ten locations require new superstructures. Two locations (ID 43 and 49) require only minor superstructure repairs. Partial repairs are required at the following 18 locations: • Little Gala Underbridge (ID 10); • Crookstone Mill Underbridge (Location ID 13); • Hollowshank Underbridge (ID 14); • Hollowshank Culvert Underbridge (ID 15); • Bower Underbridge (ID 16); • Fountainhall Culvert Underbridge (ID 17); • Plenploth North Underbridge (ID 19);


3-11

• Torquhan South Underbridge (ID 20); • Watherston Underbridge (ID 25); • Gala Bank Underbridge (ID 26); • Lugate Bridge Underbridge (ID 30); • Ferniehirst Water Underbridge (ID 31); • Bowshank North Underbridge (ID 33); • Bowshank South Underbridge (ID 34); • Harper’s Culvert Underbridge (ID36); and • Whin Water Underbridge (ID 40). New superstructures are required at the following 10 locations: • Shoestanes Underbridge (ID 5); • Watherston Culvert Underbridge (ID 23); • Flood Relief Culvert Underbridge (ID 32); • Whitelee Culvert Underbridge (ID 39); • Torwoodlee Water Underbridge (ID 42); • Ryehaugh Water Underbridge (ID 45); • Kilnknowe Underbridge (ID 46) and • 3 underbridges near Heriot (Location IDs 50-52). The replacement of an existing superstructure will require the use of cranes or similar lifting equipment located either on the existing railway embankment, or on a construction access track on the river bank. Hence, no lifting machinery would need to be located within the river environment. Three of the superstructure replacements (Torwoodlee Water Underbridge (ID 42), Ryehaugh Water Underbridge (ID 45) and Kilnknowe Underbridge (ID 46) will require medium to large scale lifting operations. Little or no in-river habitat will therefore, be affected by the proposals to repair superstructures. The creation of a new superstructure will require in-river work, although the construction areas are envisaged to be limited to 10 m upstream and downstream of the bridge location. The time taken to complete the works will vary according to the particular structure and location (see Table 3.1).

Table 3.1 Superstructure Repairs and Replacement - Duration of Construction

Phase Superstructure Repair Replacement of Superstructure Minor Span

(<3m) Major Span (>3m) Minor Span (<3m) Major Span (>3m)

Site Establishment 1 week 1 week 1 week 2 week Engineering Works 2-3 weeks 4-8 weeks 4 weeks 8 weeks Site Clearance 1 week 1 week 1 week 2 week


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3.2.3 River Diversion

The removal of the level-crossing at Heriot Station requires the realignment of the B709 over the Gala Water. The river at this location is a small meandering stream approximately 1 m wide (see Photograph 1). It is proposed that a 100 m section of the existing Gala Water be diverted from its current course, to a new parallel course to the south (approximately 70 m in length), and the existing course infilled. The river will be affected approximately 10 m upstream and downstream of the diversion points, hence the overall length affected will be approximately 120 m. The new alignment will comprise a 70 m stretch including a 30 m section of arch culvert under the new road alignment.

Photograph 1 Location of the Proposed River Diversion at Heriot (ID 6)

River Diversion • The works will include inlet / outlet works, backfilling over the culvert,

relocating the river bed material from the old water course to the new open channel section, and then infilling the current channel under the new road. Temporary bunding would be required at the upstream and downstream extremities of the new route during construction to control the movement of sediment.


3-13

Proposed River Diversion at Heriot (ID 6) (shown in red with culverted section dotted)

Cross Section of Culvert



3-14

The estimated duration of the river diversion works is seven weeks which comprises: • 1 - 2 weeks for site establishment and preparation; • 2 - 4 weeks for the engineering works; and • 1 week for removal of the equipment and tidying of the site.

3.2.4 Culvert Replacement

The proposed route passes over an existing small culvert (1.2 m span) at Shoestanes / Sandyknowe just downstream of the river diversion and approximately 50 m from the Gala Water (see Section 3.2.3). The culvert is on a minor flood drainage channel that drains nearby fields, although it was dry at the time of the surveys (see Photograph 2 and Chapter 4) and will have to be replaced.

Photograph 2 Location of Proposed Culvert Replacement at Shoestanes / Sandyknowe (ID 7)

Replacement of Concrete Culvert with Pipe Culvert • This will require the removal of the existing structure, excavation to prepare a suitable

foundation in the river bed, placement of a new pre-cast concrete culvert and inlet/outlet works and backfilling.

• The works are small scale along a length of 15 m with the areas affected likely to be approximately 5 m upstream and downstream of the culvert.


3-15


The estimated duration of the culvert replacement works is six weeks which comprises: • 1 week for site establishment and preparation; • 3 - 4 weeks for the engineering works; and • 1 week for removal of the equipment and tidying of the site.


3-16

3.2.5 Riverbank Protection

In areas where erosion is evident or predicted to be likely, especially where the river meets a bank at an acute angle, measures will be implemented to stabilise the river bank and help to ensure the structural integrity of the railway embankment. Existing bank protection works, especially riprap exist along the length of the existing railway route within the Gala Water catchment. The proposals as part of this scheme include repairs to existing protection works, for example by replacing riprap, or adding an additional layer of rock to existing areas, and by the construction of new protection works. All of the bank protection works will involve re-profiling of the bank slopes, providing a layer of armouring using riprap, concrete or gabions, and protecting the toe of the slope from scour by river flow. Three different methods of bank protection will be used depending on the location: • riprap; • concrete retaining walls; and • sheet piling. The areas directly affected by the construction of the works are estimated to cover an area 10 m upstream and downstream from the end of the structure/earthwork and up to 4 m into the river. The footprint of the structure/earthwork sections are envisaged to be the length of the bank to be protected which is specific to each location, up to 5 m up the banks and approximately 2-3 m into the river from the bank/water interface under mean flow conditions. Riprap • Riprap has been used extensively as a bank protection method along the Gala Water, and is

considered one of the most appropriate replacement / repair methods in situations where high levels of protection are required and sufficient space is available to accommodate the riprap. The works will involve re-profiling of the bank slope, some in-river excavations for the toe of the slope, installation of a geotextile/cloth liner followed by placement of rock (0.5 to 1 m diameter) from machinery located on the bank and creation of a wedge of riprap to support the toe. Temporary in-river diversion works are not usually required. The up slope portion of the riprap armouring can then be re-vegetated using native plant species typical of the local area.



3-17

Concrete Retaining Walls • Concrete retaining walls may be required in areas where there is a high risk of erosion, or

where the railway is in close proximity to the river, and there is insufficient space for other options. Construction works will require excavations to establish a base for a reinforced concrete foundation, the installation of temporary timber formwork into which the concrete is poured, and then placement of riprap or a sheet pile wall along the toe of the retaining wall to prevent scour. A sheet piled cofferdam will be required to ensure a temporary diversion of the river and dry working conditions.

Source: Scott Wilson General Solutions Report (Annex C) Sheet Piling with Riprap Berm • Sheet piling can be used to provide high levels of protection where space is limited. The

piles can be driven from machinery based on the bank to avoid in-river disturbance and no temporary in-river diversion works are required. A geotextile / filter cloth will be installed to prevent the leaching out of fine particulates, and covered with riprap, the surface of which can be covered with natural topsoil material and re-vegetated to create a riparian vegetation zone.


3-18




3-19

Riverbank protection works are required in 14 locations as follows: • riprap only (5):

• Pim House 1 (ID 22); • Craigs Wood (ID 24); • Mill Bank 2 (ID 28); • Bowshank South (ID 35); and • Bowland (ID 37).

• riprap with concrete retaining wall (2):

• Haltree (ID 11); and • Burnhouse (ID 18).

• sheet piling and riprap berm (2):

• Stagebank (ID 9); • Mill Bank 1 (ID 27);

• sheet piling and riprap berm and separate riprap (1):

• Lady’s Park (ID 29); • sheet piling with riprap installed remotely from the river bank (3):

• Gala Water / Shoestanes Burn interface (ID 4); • Whitelee House (ID 38); and • Buckholm North (ID 41).

• sheet piling with riprap installed remotely from the river bank and

separate riprap (1): • near Heriot Station (ID 8).

The estimated durations of the individual river bank works are shown in Table 3.2. • 1 week for site establishment and preparation; • 3 - 4 weeks for the engineering works; and • 1 week for removal of the equipment and tidying of the site.

Table 3.2 Riverbank Protection Works - Duration of Construction

Phase Estimated Time (Weeks) Riprap Concrete Retaining Wall Sheet Piling Site Establishment 1 1 1 Engineering Works 1 (per 10-20m) 4-6 (per 10m) 1 (per 10-20m) Site Clearance 1 1 1

3.2.6 Summary of Proposed Works

The following table provides a summary of the works required at each of the identified locations along the Gala Water where the proposed route interacts with the river.

In-river working conditions Superstructure

engineering works Substructure engineering works

Scour protection works

Riverbank Protection Works

Loca

tion

ID

Local Name Type

Tem

pora

ry in

-riv

er d

iver

sion

wor

ks

requ

ired

?

Dry

in-r

iver

env

iron

men

t

Sca

ffol

ding

req

uire

d

Bun

ding

req

uire

d

Cof

ferd

am r

equi

red

New

sup

erst

ruct

ure

(incl

udin

g de

ck)

Rep

air

supe

rstr

uctu

re (s

andb

last

, pai

nt,

wat

erpr

oof,

new

dec

k)

Rep

oint

ing

(incl

udin

g lo

calis

ed d

e-ve

geta

tion)

Min

or r

epai

rs (a

butm

ents

, pie

rs,

win

gwal

ls) (

Min

or B

H5)

Str

uctu

ral r

epai

rs to

sub

stru

ctur

e (B

H5)

Foun

datio

n re

pair

s by

she

et p

ile a

nd

grou

t (B

H2)

Oth

er

Sco

ur p

rote

ctio

n w

orks

req

uire

d?

Con

cret

e ap

ron

repa

ir a

nd r

ipra

p (B

H6)

Ren

ew s

cour

pro

tect

ion

(rip

rap)

(BS

1)

Cul

vert

rep

lace

men

t

Riv

er d

iver

sion

via

new

cul

vert

Tota

l len

gth

of e

xist

ing

RB

P (m

)

Tota

l len

gth

of p

ropo

sed

RB

P (m

)

SOLUTION

50 UB 45 - Nr Heriot Culvert Bridgeworks NO Y Y Y Y NO 51 UB 47 - Nr Heriot Bridgeworks NO Y Y Y Y NO 52 UB 48 - Nr Heriot Bridgeworks NO Y Y Y NO 4 Gala Water/Shoestanes Burn

interface RBP 55 240 EH3A (remote) (240m)

5 UB 49 - Shoestanes Bridgeworks NO Y Y Y NO 6 UB 49-2 Heriot / New road

alignment Diversion YES Y [1] Y Y

7 Un-Named Culvert at Shoestanes

Culvert replacement NO Y Y [2] Y

8 UB 48 - UB 49 Near Heriot Station

RBP 25 150 EH3A (remote) (75m) and ES1 (75m)

9 OB 50 - UB 51 Stagebank RBP 105 230 EH3 (230m) 10 UB 52 - Little Gala Bridgeworks YES Y Y Y Y Y 11 UB 52 - UB 53 Haltree RBP 190 160 ES1 (140m) and EH1 (20m) 13 UB 53 - Crookstone Mill Bridgeworks YES Y Y Y Y 14 UB 54 - Hollowshank Bridgeworks YES Y Y Y Y Y Y 15 UB 55 - Hollowshank Culvert Bridgeworks NO Y Y Y NO 16 UB 56 - Bower Bridgeworks YES Y Y Y Y Y 17 UB 58 - Fountainhall Culvert Bridgeworks YES Y Y Y [3] Y 18 UB 58 - OB 59 Burnhouse RBP 40 110 ES1 (70m) and EH1 (40m) 19 UB 60 - Plenploth North, Water Bridgeworks YES Y Y Y Y 20 UB 61 - Torquhan South Bridgeworks YES Y Y Y Y 22 UB 62 - UB 63 Pirn House 1 RBP 45 70 ES1 (70m) 23 UB 64 – Watherston Culvert Bridgeworks YES Y Y Y Y NO 24 UB 64 - UB 65 Craigs Wood RBP 20 115 ES1 (115m) 25 UB 65 - Watherston Bridgeworks YES Y Y Y Y Y 26 UB 67 - Gala Bank Bridgeworks YES Y Y Y Y Y 27 UB 67 - OB 68 Mill Bank 1,

Stow RBP 200 230 EH3 (230m)

In-river working conditions Superstructure

engineering works Substructure engineering works Scour protection

works Riverbank Protection Works

Loca

tion

ID

Local Name Type

Tem

pora

ry in

-riv

er d

iver

sion

wor

ks

requ

ired

?

Dry

in-r

iver

env

iron

men

t

Sca

ffol

ding

req

uire

d

Bun

ding

req

uire

d

Cof

ferd

am r

equi

red

New

sup

erst

ruct

ure

(incl

udin

g de

ck)

Rep

air

supe

rstr

uctu

re (s

andb

last

, pai

nt,

wat

erpr

oof,

new

dec

k)

Rep

oint

ing

(incl

udin

g lo

calis

ed d

e-ve

geta

tion)

Min

or r

epai

rs (a

butm

ents

, pie

rs,

win

gwal

ls) (

Min

or B

H5)

Str

uctu

ral r

epai

rs to

sub

stru

ctur

e (B

H5)

Foun

datio

n re

pair

s by

she

et p

ile a

nd

grou

t (B

H2)

Oth

er

Sco

ur p

rote

ctio

n w

orks

req

uire

d?

Con

cret

e ap

ron

repa

ir a

nd r

ipra

p (B

H6)

Ren

ew s

cour

pro

tect

ion

(rip

rap)

(BS

1)

Cul

vert

rep

lace

men

t

Riv

er d

iver

sion

via

new

cul

vert

Tota

l len

gth

of e

xist

ing

RB

P (m

)

Tota

l len

gth

of p

ropo

sed

RB

P (m

)

SOLUTION

28 UB 67 - OB 68 Mill Bank 2, Stow

RBP 140 150 ES1 (150m)

29 OB 68 - UB 69 Lady's Park, Stow

RBP 275 400 EH3 (300m) and ES1 (100m)

30 UB 70 - Lugate Bridge Bridgeworks YES Y Y Y Y 31 UB 72 - Ferniehirst Water Bridgeworks YES Y Y Y Y NO 32 UB 73B - Flood Relief Culvert Bridgeworks NO Y Y Y NO 33 UB 74 - Bowshank North Bridgeworks NO Y Y Y Y NO 34 UB 77 - Bowshank South Bridgeworks NO Y Y Y Y NO 36 UB 78 - Harper's Culvert Bridgeworks NO Y Y Y Y NO 35 UB78 - Bowshank South RBP 45 100 ES1 (100m) 37 UB 80 - OB 81Bowland RBP 410 600 ES1 (600m) 38 OB 81 - UB 82 Whitelee House RBP 130 130 EH3A (remote) (130m) 39 UB 82 - Whitelee Culvert Bridgeworks YES Y Y Y Y Y 40 UB 84 - Whin Water Bridgeworks YES Y Y Y Y Y 41 UB 84 - UB 85 Buckholm,

North RBP 10 250 EH3A (remote) (250m)

42 UB 87 - Torwoodlee Water Bridgeworks YES Y Y Y Y Y [4] Y 43 UB 87B - Torwoodlee Flood

Relief Culvert Bridgeworks NO Y Y[5] Y NO

45 UB 92 - Ryehaugh Water Bridgeworks NO Y Y Y Y NO 46 UB 95 - Kilnknowe Bridgeworks YES Y Y Y Y Y 49 UB 104 - Red Bridge Bridgeworks YES Y Y[5] Y Y Y Y


3-22

3.3 OPERATION

3.3.1 Overview

Once operational, the railway will have no direct impacts on the Gala Water. Indirect effects may result from discharges from the operating trains, drainage from the track especially where old track is reused and regular maintenance activities to keep the track free of ice and leaves. Each of these is considered below.

3.3.2 Train Movements

A total of 4 trains per hour will operate between Newcraighall and Tweedbank, during the period 05:30 and 23:30. The trains will all be passenger trains (Diesel Class 158), and there are currently no proposals to use freight trains.

3.3.3 Train Discharges

Regular maintenance of trains ensures that all trains operate at an optimum performance level. As part of train maintenance, it is necessary to replace items including oils, filters, anti-freeze and batteries. These activities take place within the workshops and therefore there is no effect to the tracks or possible effect to water systems. Discharges from the operating trains can still occur, however, and may include oils, coolants, brake fluids and grease which can drain to trackside ditches and can enter watercourses or drain through the foundation of the tracks. Leaks of these substances are only likely to be of significance in sidings where contamination can accumulate over time and runoff may contain a range of contaminants. Biodegradable greases are also available and their use may reduce the potential for drainage water pollution. The trains will discharge effluent from the toilets which will contain detergents as well as faecal bacteria, and are left to decompose naturally on the track. New toilet systems are currently being introduced, and may be operational once this route is opened.

3.3.4 Track Maintenance

Track maintenance is dependant on track activities such as type of track laid, type of trains using the track and line speed. Special Areas of Conservation (SAC) are marked on the sleepers in areas of concern. Plates are put in place with areas of demarcation. Network Rail takes all environmental issues into account and ensures that maintenance workers will not disturb any sites containing an SAC. Special permission is applied for from SEPA with details of site and works planned and a permit is issued before any work can commence. A risk assessment is carried out for


3-23

any renewal works planned and for species of conservation, for example badgers, the necessary mitigation put in place such as badger crossings. The following information has been provided by Network Rail for the associated maintenance of their rail tracks. Structures

Network Rail examines all structures within the Network Rail Standard GC/RT 5100 ‘Safe Management of Structures’. The examination and timeframe of each inspection undertaken per structure is: • Flood protection: every year; • Earthworks/embankments: dependant on the conditions associated with

the area. Initial assessment between every 1-10 years; and • Bridges:

o visual assessment every year; o detailed examination every six years.

De-icing

De-icing is a process that is not adopted by Network Rail. Alternative management of tracks with non-de-icing chemicals includes running trains during the night to keep tracks clear. Currently Network Rail ensures ice does not form on the Switch and Cross Points by installing heating devices (pers comm. 24/10/05). Leaf Mulch

Leaf mulch can accumulates on the tracks and acts in a similar manner as black ice on roads, causing trains to slip and slide resulting in delays and possible damage to trains and tracks. Network Rail uses ‘water-jetting’ trains which emit water at an equivalent pressure of 1,000/bar, and ‘leaf-busting’ teams using scrubbers, sand sticks and Natrusolve, a product that dissolves the leaf mulch, hence the tracks should remain relatively clear at most times (Network Rail Press Release, 18th October 2005).

3.3.5 Weed Control

Management of the railway corridor must take place to ensure safe and continual use of the railway. This will include the management and control of the spread of Japanese Knotweed and Giant Hogweed along the edges of railway tracks and railway owned land. Both species commonly occur along watercourses. Currently Network Rail employs two methods of controlling vegetation and weed species. The use of a Glyphosphate based herbicide has been approved for use near waterways by SEPA and is effective against controlling grass and


3-24

weed species within the railway corridor. The table below provides affective herbicides used by Network Rail and their appropriateness for use near water environments.

Table 3.3 Possible Herbicide Species

Herbicide Affects grasses? Approved for use in or near water?

Persistency

Glyphosate Yes Yes Non-persistent 2,4-D Amine No Yes 1 month Triclopyr No No 6 weeks Imazapyr Yes No 9 months Picloram No No 2 years

3.3.6 Pest / Feral Animal Control

Network Rail does not use any form of pesticide within the rail corridor. Problems with rabbits are dealt with in a humane manner by a specialist contractor.


4-1

4 BASELINE SURVEYS

4.1 SURVEY SCOPE

As described in Section 2.4, the required surveys were determined through review of existing survey information and in consultation with SNH. The survey areas were concentrated around the 45 work sites (as described in Section 3), extending 100 m upstream and 400 m downstream of the proposed engineering works, to cover more than the area predicted to be affected by the works. In the case of point features, such as bridges, the survey length is 500 m and in the case of linear features such as river bank protection works, the survey length includes the length of the works plus 500 m. If the defined survey lengths for different engineering features overlap, the survey reaches were amalgamated into one continuous survey reach. There were 34 survey reaches in total. The locations of the survey reaches are presented within Figure 4.1. Access was obtained for the majority of survey reaches. However, as can be seen from the table, reaches 16 and 33 extended only to 244 m and 355 m respectively due to access restrictions. Other reaches shorter than 500 m, either overlapped with other survey reaches or were located on tributaries (reaches 17, 30 and 39). The surveys included: • hydrology and water quality; • river habitat survey; • riparian and bankside vegetation; • macrophyte survey; • otter; • Atlantic salmon; and • lamprey. The methodology for each survey type is described in Section 4.2 and the survey results are presented in Section 4.3.

4.2 METHODOLOGY

4.2.1 Hydrology and Water Quality

The objectives of the hydrological survey work was to: • Develop an understanding of the hydrological regime of the catchment;

and • Place the survey period within a hydrological context.


4-2

Figure 4.1 Ecological Survey Reaches and Corresponding Engineering Proposals (© Crown copyright. All rights reserved. Licence No. 100044822)

The detailed works at specific locations are shown in Annex K.

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9

87 6

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484746

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3635 34

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30

29

2827

2625

24232221

20

19

1817

161514 13

12 1110

52 5150

River Diversion

River Bank Protection

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Culvert Renewal

Surveyed Reaches



4-3

• Evaluate whether the outcomes of the baseline ecology surveys may have been influenced by extreme flow events within the recent hydrological past.

• Review SEPA’s historical water chemistry data and gain an overview

understanding of the sediment dynamics of the catchment. The analyses conducted to meet these objectives are presented in full within Annex D. The analysis has primarily used the historical daily gauged data for the Gala Water (gauge number 21013) provided by the Scottish Environmental Protection Agency (SEPA) for the post 1986 period and reconciled with the longer flow record held on the National River Flow Archive (held by the Centre for Ecology and Hydrology (CEH)). Once differences were reconciled this provided a flow time series extending from October 1964 to October 2005. SEPA also provided routinely monitored water chemistry data for the monitoring site at Gala Foot. The CEH/WHS Low Flows 2000 software was used to assess the hydrological homogeneity of the catchment and confirm that the measure flow record at Galashiels is representative of the whole catchment. The methodology utilised flow duration curve analyses, flood frequency analysis and time series analyses. The full methodology is presented within Annex D.

4.2.2 River Habitat Survey

A river habitat survey was conducted using the standard recognised methods outlined in the Environment Agency’s River Habitat Survey (RHS) Guidance Manual: 2003 Version to establish the range of physical habitat types within the Gala Water. It was conducted between July and September 2005 by Northern Ecological Surveyors. The survey was undertaken along the length of the Gala Water where it runs parallel to the scheme and at its confluence with the River Tweed in Galashiels along 500 m survey reaches repeated at 2 km increments (see Figure 4.1). The survey recorded physical habitat features both in-river and bankside in the areas that may be affected by the works. Bank and channel substrates and flow type were recorded which helped to identify suitable habitat for the qualifying fish species. The survey also recorded the presence or absence of the qualifying aquatic plant communities. The RHS Survey forms are presented in Annex E.

4.2.3 Riparian Vegetation

A Phase 1 Habitat Survey (1) was undertaken in September 2005 using standard methodology (JNCC 1993) (2) but extended for use in Environmental Impact Assessment (3). The extent of the survey varied depending on the

(1) A standardised system developed by the former Nature Conservancy Council to allow identification of areas of habitat of nature conservation interest relatively rapidly over a wide area. (2) Joint Nature Conservation Committee (1993) Handbook for Phase 1 Habitat Survey - A Technique for Environmental Audit, Joint Nature Conservation Committee, Peterborough. (3) Institute of Environmental Assessment (1995) Guidelines for Baseline Ecological Assessment, Spon, London.


4-4

nature and extent of the proposed engineering works. Thus for a crossing point (under bridge or culvert), a circle of at least 50 m radius was mapped around the intersection of river and railway. In the case of river protection works, the entire strip of land between the watercourse and the railway mapped ie for the length of the proposed engineering works. Where two locations lay closely adjacent (eg survey locations 35 and 36), a composite map was drawn covering both the locations. This practice was most important for the cluster of locations south from Heriot station (survey locations 52 and 4-8, including the river diversion works), where a corridor at least 50 m on both sides of the railway was mapped. The objectives of this survey were: • to construct terrestrial habitat maps at 1:1000 scale for each survey site; • to characterise the habitats in terms of their dominant species and where

possible to relate the vegetation types to the National Vegetation Classification (NVC) (1) communities; and

• to identify any habitats of nature conservation value particularly where

railway construction might have damaging effects that would need to be mitigated.

The full report is presented in Annex F.

4.2.4 Macrophytes

The survey was conducted between July and September 2005 using standard Joint Nature Conservation Committee (JNCC) macrophyte survey method (2) (Holmes et al. 1999) to record river vegetation in the survey reaches. The survey recorded the variety and extent of aquatic and bank vegetation in the area of the proposed work plus 100 m upstream and 400 m downstream. The macrophyte data recorded were then used to categorise the sites into river types and to gauge their conservation status according to the occurrence of certain key species. Separate records were made of aquatic macrophytes that are more or less permanently submerged and bank records for species typically subject to alternate inundation and exposure with variations in river levels. A 3-point scale was used to indicate the percentage area covered by each species as follows: 1 = < 0.1% 2 = 0.1-5% 3 = >5%

(1) Rodwell J S (1991-2000) British Plant Communities (Five vols), Cambridge: Cambridge University Press. (2) Holmes N T H, Boon P, Rowell T (1999) Vegetation Communities of British Rivers: A Revised Classification. JNCC Production.


4-5

Relative plant cover was also recorded, to provide information on the abundance of one species in comparison with the other species present. The units used were: 1 = Rare 2 = Occasional or Frequent 3 = Abundant The JNCC checklist of taxa was used. Additional taxa not on the list were recorded separately to provide comprehensive data for the species list of each site. The full report is presented in Annex G.

4.2.5 Otter

An otter survey was undertaken in 2002 by Heritage Environmental Consultancy for ERM as part of the survey work undertaken to inform the EIA. A further survey was undertaken to specifically inform the Appropriate Assessment. This was undertaken by Capreolus Wildlife Consultancy for ERM in September 2005 using standard methodology outlined in The New Rivers & Wildlife Handbook (1). With the exception of localised areas of impenetrable scrub or inaccessible parts of urban Galashiels, the entire length of the Gala Water was walked from Heriot in the north to the confluence with the River Tweed at Galashiels in the south. Both banks of the Gala Water were walked and, where safe to do so, the river was waded in order to investigate otherwise inaccessible bank features. Tributaries were walked for a minimum distance of 100 m upstream. In the vicinity of proposed riparian or in-river engineering works the survey area was extended to include an area of search of 100 m radius. Within the areas walked the following species-specific methods were used to establish the contemporary distribution of animals on the site. The surveyed areas were systematically searched for evidence of use by otters in the form of: • Spraints: otters mark their home ranges by depositing highly characteristic

spraints (faeces) on prominent features such as boulders, grass tussocks and tree bases;

• Otter shelters: comprising holts (underground) or couches (above ground).

Couches are frequently located in dense vegetation cover or natural cavities formed by bank side trees. Holts may be excavated or located in enlarged rabbit holes or rock piles;

• Footprints; and

(1) Ward D, Holmes N, Jose P (1994) New Rivers and Wildlife Handbook.


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• Sightings. The full report is presented in Annex H.

4.2.6 Atlantic Salmon

The Gala Water is a productive salmon recruitment tributary and is well populated by both early and late grilse (1) and in 1995 the Tweed Foundation recorded juvenile salmon from 24 out of 28 key juvenile salmonid locations in the Upper Tweed (2). As discussed in Section 2.4, based on information provided by the Tweed Foundation and discussions with SNH, it has been assumed that that where suitable salmon spawning and juvenile habitat exists within the Gala Water, it will be readily utilised by Atlantic salmon and thus a confirmatory electro-fishing campaign was not considered necessary. As for the other surveys, at least a 500 m stretch around the engineering work locations was surveyed. The surveys were based on an extension of the River Habitat Survey (3) (see Section 4.2.2). The dominant meso-habitats extents were mapped (see Annex I), with the average channel cross-section and dominant and sub-dominant substrate noted (see Table 4.2). These were quantified together with artificial and natural erosion/deposition features (see Table 4.3) and significant riparian overhanging vegetation.

Table 4.1 Physical Descriptions of Meso-Habitat Types as Presented in Maddock (1999) (4) and RHS Field Survey Guidance (2003) (5)

Meso-habitat Symbol Physical Description Riffle* RF Shallow rapids, high current velocity, disturbed surface,

partially submerged obstructions Run† RN Area of swiftly flowing water without surface agitation or

surface waves Pool* P Discrete area between faster reaches, velocity reduced,

depth variable Glide† G Slow moving shallow run with calm water and little or no

surface turbulence Cascade* C Swift current, exposed rocks and boulders, considerable

turbulence, consisting of a stepped series of drops Broken standing wave‡

BSW White water tumbling waves

* Mesohabitat defined in Maddock (1999), identified by Brooker (1981) (6) † Mesohabitat defined in Maddock (1999), identified by Kershner and Snider (1992) (7) ‡ Flow type defined in RHS Field Survey guidance (2003)

(1) Spawning stage of the salmon lifecycle. (2) Panter, A. 2003. Extension to the River Tweed cSAC update on Proposals and Progress. Scottish Natural Heritage (Unpublished). (3) RHS, 2003. River Habitat Survey in Britain and Ireland: Field Survey Guidance Manual (2003 Version). (4) Maddock, I.P., 1999. The Importance of Physical Habitat Assessment for Evaluating River Health, Freshwater Biology,

41, p373-391. (5) RHS, 2003. River Habitat Survey in Britain and Ireland: Field Survey Guidance Manual (2003 Version). (6) Brooker, M.P., 1981. the impact of impoundments on the downstream fisheries and general ecology of rivers. Advances in Applied Ecology, Volume 6. Acedemic Press, New York. (7) Kershner, J.L. and W.M. Snider, 1992. importance of a habitat-level classification system to design in-stream flow studies. River Conservation and Management. Wiley, Chichester.


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Table 4.2 Definition of Substrate Sizes as Presented in RHS Field Survey Guidance (2003)

Substrate Symbol Physical Description Artificial A Obviously non-natural bed material (eg concrete, bricks) Bedrock BR Underlying solid rock Boulder B Large rocks > 256 mm Cobble C Loose material 64 – 256 mm Large Gravel LG Loose material 16 – 64 mm Small Gravel SG Loose material 2 – 16 mm Sand SD Particle size < 2 mm, but > 0.06 mm Silt ST Very fine particles

Table 4.3 Description of Natural and Artificial Features

Feature Symbol Physical Description Artificial Rip Rap RR Boulders purposely tipped or laid along the bank face to

protect it from erosion Sheet Piling SP Vertical, interlocking, steel sheets protecting the bank face Wood piling WP Wooden poles, or horizontal/vertical planks protecting the

bank face Gabion GA Stones in wire baskets, installed to protect the bank from

erosion Brick/laid stone ST Cemented wall or un-cemented laid stones Concrete C Cemented bank face reinforcement that forms a solid

revetment Tipped debris TD Discarded material from, for example, farming and

building works Poached PO Bank significantly trampled or puddle by livestock Weir Permanent in-channel structure installed to control river

flows/levels Ford FD Permanent, shallow fording place Inlet/Outlet IL/OL Water intake or outlet Natural Eroding cliff EC Bank face profile is vertical or near vertical with a clean

face Undercut cliff UC Bank face profile is undercut Point bar PB A distinctive depositional feature of unconsolidated river

bed material located on the inside of a distinct meander bend

Side bar SB A distinctive depositional feature of unconsolidated river bed material located along the margins of the river

Mid bar MB A distinctive, in-channel, depositional feature of unconsolidated river bed material

For each meso-habitat mapped, the suitability for salmon spawning and juvenile habitats was assessed on the average channel depth, dominant and sub-dominant substrates, and presence of overhanging riparian vegetation. For each life stage, the depth and substrate was assigned a score of optimal, sub-optional or marginal based upon information published in the literature for life stage suitability (see Annex I for details). The scores for depth and substrate were combined with the presence of overhanging vegetation, to give an overall score of optimal, sub-optional, marginal and unsuitable for each meso-habitat. This was then presented as a percentage for each score per


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surveyed reach. In addition, due to spawning occurring in the transitional period between pools and riffles, the number of transitions between meso-habitats for each survey reach was calculated per unit length as a measure of the channel diversity, which equates to a transition density. For example, a (run, pool, riffle, run, pool, riffle) meso-habitat sequence over a reach length of 50 metres would have a transition density of 0.1 m-1. Full details are presented within Annex I for the mapping of the habitat indices to measures of habitat suitability.

4.2.7 Lamprey

Habitat Suitability

An assessment of the presence and utilisation of spawning and juvenile habitats was undertaken, in addition to identifying any obstacles to upstream migration within the Gala Water. These surveys were divided into one for spawning and migration habitats and one for juvenile habitats. The spawning and migration habitats were assessed based on a survey of potential habitat suitability using the habitat survey data collected for the assessment of habitat suitability for Atlantic salmon (see Section 4.2.6). The juvenile habitat survey was based upon a mapping of all potential juvenile survey habitats. The mapping of habitat survey data to habitat suitability for lamprey spawning is discussed in detail within Annex J. The assessment of habitat suitability was carried out in the same way it was for salmon, with the scores for depth and substrate being combined with the presence of overhanging vegetation, to give an overall score of optimal, sub-optional, marginal and unsuitable for each meso-habitat, presented as a percentage for each score for each surveyed reach. Barriers to migration were assessed on the basis of the results of the migration barrier survey conducted for Atlantic salmon. Electro-fishing surveys

The habitat suitability details along with photographs were studied by the Tweed Foundation and ranked in order of suitability for lamprey on a scale of 1 to 10, with 10 being optimal. All areas scoring four and above were listed for electro-fishing surveys, as were two extents ranked less than four for control purposes. The permanence of the silt beds (ie likelihood of being washed out in winter spates) was also considered as this will contribute to evaluating whether the potential loss of a habitat will significantly affect the integrity of the lamprey population within the Gala Water. The likely reasons for the occurrence of the silt beds were divided into six categories. This indicates that few of these habitats are permanent features and therefore could be lost through scour during winter spates. The full list of sites, the ranks given and those chosen for survey are given in Annex J. The sampling methodology for electro-fishing was based on the semi-quantitative method recommended for use on ‘sub-optimal’ lamprey habitat


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in SAC rivers presented in Harvey and Cowyx (1). This methodology involves electro-fishing against the flow, moving a Pulsed DC current slowly over areas of sediment, and catching the lamprey larvae as they attempted to escape from their burrows. The time taken to cover an area, the length of bank fished and the average width of the area fished were all recorded, allowing data to be presented in four ways: • total catch; • numbers per m2; • numbers per minute; and • numbers per metre length of bank. River and Brook Larvae can be distinctly differentiated from Sea larvae but are not so readily distinguishable from each other. Larger Brook lamprey can be differentiated on the basis of size otherwise field identification is on the basis of physical differences between macropthalmia (late larvae stage). River lamprey can only be positively identified as present if their macropthalmia are found. However, brook larvae are identified on the basis of not identifying macropthalmia as River lamprey. The identification of lamprey is discussed fully within Annex J together with issues regarding sampling efficiency and the approach to habitat ranking. The abundances of lamprey in SAC rivers are classified using two measures as follows: • a density estimate based on optimal habitat; and • a density based on a catchment-wide survey that includes a diversity of

habitats. The attributes for compliance with favourable status are defined within Harvey and Cowyx (2) as: Optimal habitat

• Population density river/brook lamprey ammocoetes - > 10 /m2 • Population density river/brook lamprey ammocoetes (chalk streams) -

> 5 /m2 • Population density sea lamprey ammocoetes - 0.2 /m2

Catchment perspective

• Population density river/brook lamprey ammocoetes - > 2 /m2 • Population density sea lamprey ammocoetes - 0.1 /m2

The above classification was used as a guide, where optimal defines those habitats with densities greater than 10 /m2, sub-optimal for those habitats

(1) Harvey J P, Cowyx I G (2003) Monitoring the River, Brook and Sea lamprey: Conserving Natura 2000. Rivers Ecology

series No 7. English nature, Peterborough. (2) Ibid.


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within the range of 2 – 10 /m2 and marginal for those with densities less than < 2 /m2. In the assessment of lamprey distribution and abundance in the River Tweed SAC / SSSI in 2004 (1), survey locations were chosen to give maximum geographical coverage, and three sampling sites within 100 m of the bank were selected at each location. This approach is an unbiased sampling approach that is not biased towards preferentially sampling areas of good or even suitable habitat. The electro-fishing survey approach used was biased to survey silt beds with potentially suitable physical habitat present.

4.3 SURVEY FINDINGS

4.3.1 Hydrology and Water Quality

The Gala Water is confluent with the Tweed at Galashiels. The river drains from the Moorfoot hills and predominantly has a natural flow regime with very little water use within the catchment. The catchment contains sedimentary rocks from the Ordovician and Silurian period, mainly shales, mudstones, slates, and greywackes. Within the valley of the Gala Water, there are significant deposits of glacial debris. The soils are generally clay/loam across the catchment. The catchment has an average annual rainfall of 930 mm and a contributing catchment area of 207 km2 at Galashiels. The river flow within the catchment has been continuously gauged at Galashiels (National River Flow Gauging Station number 21013) since 1964. The Gala Water catchment is very dynamic as evidenced by the baseline surveys which have demonstrated that the river bed substrate is very mobile and the river channel is strongly influenced by erosion and deposition processes. These characteristics are thought to strongly influence the habitat within the catchment for the qualifying interests. To place the baseline surveys within context, it is essential to understand the catchement hydrology of the recent past, to evaluate how representative the baseline surveys are of the long term. For example, if the recent hydrological past contains a greater incidence of very high flow than might be expected by chance, this would probably have a deleterious impact on the instream macrophyte communities. If this is the case, the surveys might not be representative of the long-term potential communities within the Gala Water. The physical habitat mapping surveys represent a snapshot of the system; it is therefore necessary to evaluate the hydrological context in which those surveys were conducted. The analyses have confirmed that the Gala Water is a highly dynamic, flashy catchment with significant erosion potential. The period of survey (beginning of July to the end of September 2005) was a period of lower flows within the

(1) Campbell, R.N.B. and P. Corson, 2004. The Assessment of Lamprey Distribution and Abundance in the River Tweed Candidate Special Area of Conservation / Site of Special Scientific Interest. Report Commissioned by SNH from The Tweed Foundation

(unpublished)


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catchment but fairly typical for the time of year. The average exceedence percentile was 80%, that it could be expected that the river flows at the survey locations would be lower than the flows during the survey period for 74 days within a year, on average. An analysis of the hydrology of recent years has shown that the last significant floods within the catchment were in late 2002. This gap is approximately equal to the average recurrence interval for the mean annual flood within the catchment and thus the results of the surveys are unlikely to be biased as a consequence of recent flood events resulting in unusual scour of the river channel. Water chemistry data provided by SEPA demonstrate that water quality of Gala Water is excellent, lying within the A1 class of SEPA’s river classification. The water chemistry data does show that the suspended sediment concentrations within river flows greater than the Q10 flow (the flow that is equalled or exceeded for 10% of the time on average) are high. Considering the temporal occurrence of Q10 flows demonstrates that fine sediment deposition during construction is likely to be re-entrained relatively quickly. The results are discussed further in Annex D.

4.3.2 River Habitat Survey

The River Habitat Survey recording forms are included in Annex E.

4.3.3 Riparian Vegetation

CEH hold historical botanical records for the Waverley Railway from 1970 (1). The 2005 survey included old track bed, verges and railway engineering features (cuttings, embankments, bridges etc) which was compared with the 1970 data. For much of the length of the railway, there are few terrestrial habitats of interest that need further assessment given the mitigation measures proposed and provided construction works are confined to within 50-60 m of the present track. Most of the common habitat types are of low nature conservation value or would not be damaged unduly by the proposed engineering works. However, there are several sites where habitats immediately adjacent to the railway have significant importance (see Annex F for associated target notes): • semi-natural broadleaved woodland (A1.1.1) in the Torwoodlee and

Ryehaugh area Engineering locations 38 – 46 (inclusive);

(1) Beattie, E.P. (1972). The botanical survey of the railway line between Gorebridge and Galashiels. Scottish Wildlife Trust (Lothian Branch)


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• marshy grassland (B5) at Hollowshank (engineering location 13 and 14), from Hangingshaw north-westward (engineering locations 50-52 and 4-8) and to a lesser extent at Plenploth (engineering location 19; and

• tall-herb floodplain fen (E3.3) immediately upstream of Heriot

(Engineering location 51). In addition, several railway cuttings held unimproved neutral grassland (B2.1) that was considerably more species-rich than any other grassland observed locally, either in the mapping exercise or in travelling between sites. These cuttings are mostly outwith the area targeted for terrestrial survey, since the topography makes it unlikely that such habitats will occur within close proximity to the Gala Water. Nonetheless, it is important to register the presence of such vegetation, and should construction of the railway go ahead, special care should be taken to protect these grasslands, notably within deeper cuttings with shallow soils and exposed rocks. It is also worth noting that the railway ballast and river-shingle provided some interesting records of uncommon hybrids (within the genera Rumex and Salix), as well as populations of several uncommon neophytes that may be spreading in the Lothians and Borders on this type of open and/or disturbed habitat where competition is reduced. These records, together with any previously unknown sites for the more local native species, will be notified to the relevant BSBI (1) recorders. Copies of the field maps are presented included in Annex F together with the accompanying map sheet and target note records. The full lists of the habitats that were recorded during the survey are presented within Section 3.2 of Annex F together with their distribution along the railway and the typical composition of the vegetation. An indication of the extent of each habitat is given, as a rough percentage estimate of the total surveyed area.

4.3.4 Macrophytes

Ranunculus vegetation is usually associated with relatively unpolluted waters and is found in a variety of river types. A range of Ranunculus species may dominate this habitat type, including Ranunculus trichophyllus, Ranunculus fluitans, Ranunculus peltatus, Ranunculus penicillatus ssp. penicillatus, Ranunculus penicillatus ssp. pseudofluitans and Ranunculus aquatilis. In the Tweed, the gradual change in nutrient status from oligotrophy in its upstream reaches, to eutrophy in the downstream reaches is reflected in a gradual shift in dominance amongst the floating Ranunculus species. The main river and its tributaries support R. penicillatus ssp. pseudofluitans in its most northerly location, R. fluitans, R. aquatilis, R. peltatus and a wide variety of interbreeding hybrids. As such, the Tweed system is unusual in its representation of several of Ranunculus communities recognised in Britain within this habitat type. An aquatic plant survey of the Tweed and its

(1) Botanical Society of the British Isles.


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tributaries in 1997 found that Ranunculus vegetation was recorded from 35 of the 42 x 500 m survey stretches along the main river, as well as eight of the 14 stretches in the River Teviot. In addition, a survey of the Whiteadder and the Blackadder in 1990 showed that Ranunculus was present in the upper reaches of these tributaries as well, with the latter supporting R. circinatus. The range of species and hybrids that occur on the Tweed, together with their extensive distribution throughout the main stem of the river, thus sets the Tweed apart as the best example of this Annex I habitat type in Scotland. Observations in the field suggest there are three main types of instream habitat used by macrophytes and four marginal types. All are defined by substrate type and are recognisable hydromorphological features. They are often associated with modifications to the channel or banks and provide an insight into potential impacts associated with alterations to channel morphology. The habitat types and their occurrence in the Gala Water is summarised below: Instream

• Cobble/pebble shallow glides, runs and riffles. This was by far the most common habitat type and supported aquatic plants of interest. The bed rarely felt armoured under foot suggesting it is highly mobile. Diatoms and filamentous algae were common on this substrate type. Water crowfoots (Batrachion Ranunculus spp.) and occasionally curled pondweed (Potamogeton crispus) were found on the cobble/pebble mix. They were almost always positioned near the edge of the channel in slower flowing water. The few plants that were found in the centre of the channel were small and are, most likely, subject to winter washout. The site on the River Tweed (Site 49) was the only location where large stands of water crowfoot developed and these were located toward the centre of the channel on cobble substrate.

• Boulders and Bedrock. Mosses and occasionally liverworts were found on

submerged or partially submerged bedrock and boulders. Submerged and collapsed riprap and bridge supports acted as an artificial substitute for naturally occurring boulders and bedrock. Hence many of the sites with old rail bank protection supported mosses. Boulders were an occasional rather than a common component of most survey reaches. Aquatic mosses (Fontinalis spp. & Rhynchostegium riparioides) occurred exclusively on this group of substrates.

• Slow water with silty deposits. Habitat of this type occurred where

tributaries entered the main river. Often pools are present at the mouth of the tributaries where the water slowed and silt deposited. Immediately upstream of the inflow, a zone of shallow slack water often occurred and silt was also deposited here. Similar conditions occurred where culverted streams running under the railway entered the Gala Water or where the river appeared over-deepened at re-aligned sections of channel. Canadian waterweed (Elodea canadensis) and lesser pondweed (Potamogeton pusillus)


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occurred exclusively in the silty areas. The conditions also favoured branched burr reed (Sparganium erectum), curled pondweed (P. crispus) and the water crowfoots that produce laminar, floating leaves, eg pond water crowfoot (R. peltatus).

Marginal

• Gravel side/point bars. These were a common feature of many sites and they supported a flora with species uncommon in other marginal habitats. Water-cress (Rorripa nasturtium-aquaticum/ microphyllum), bog stitchwort (Stellaria uliginosa), redshank (Persicaria maculosa), procumbent pearlwort (Sagina procumbens), knotgrass (Polygonum aviculare) and the invasive monkey flower (Mimulus agg.) were all commonly encountered.

• Eroding earth cliffs (sensu RHS). Bare earth cliffs were a poor habitat

supporting mainly horsetails (Equisteum spp.). The moss Pohlia wahlenbergii was also found in this habitat.

• Wooded earth banks. Under the shade of the trees, liverworts grew among

tree roots where the water had begun to expose bare earth. Concephalum conicum, Pellia species and Lunularia cruciata were all common. In the gaps between the trees, wood club rush (Scirpus sylvaticus) often flourished.

• Unshaded earth bank. This was the most common marginal habitat.

Throughout the entire catchment reed canary-grass (Phalaris arundinacea) dominated the margins. Water forget-me-not (Myosotis scorpioides) was also frequently encountered. Juncus species were most frequent in the upper part of the catchment. At a number of sites butterbur (Petasites hybridus) formed extensive stands.

The full detail of the survey results are presented within Annex D. The principle results and conclusions from the survey are summarised below: • the water quality is good enough to sustain a CB community. The Gala

Water contains aquatic plant communities of conservation interest throughout most of the catchment and they require protection. Sites at the top of the catchment have less diverse aquatic plant communities than those lower down;

• aquatic vegetation was sparse at all the sites, apparently due to the mobile

nature of the substrates. This is common within the Tweed system; • the river supports a diverse plant community with significant water

crowfoots (Batrachion Ranunculus), liverworts and mosses (Bryophytes); • marginal vegetation accounted for the majority of species recorded. The

bank vegetation was dominated by reed canary-grass (Phalaris arundinacea) throughout the catchment;


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• the water crowfoot (Batrachion Ranunculus) community in the Gala Water as a whole is diverse. Batrachion Ranunculus species were recorded in low numbers at 20 of the 38 sites surveyed. Ranunculus fluitans x aquatilis, Ranunculus peltatus, Ranunculus penicillatus ssp. pseudofluitans and Ranunculus hederaceus were recorded;

• bryophytes of interest occurred at most sites. Instream aquatic mosses

(Fontinalis spp., Rhynchostegium riparioides and Brachythecium rivulare) were limited to sites with suitable habitat. R. riparioides was often the most dominant instream macrophyte;

• many of the sites on the Gala Water have communities which are very

similar to the CB4 community type. Comparison with other surveys on tributaries of the Tweed suggest that Batrachion Ranunculus and Potamogeton species are more widespread on the Gala Water than on the nearby Ettrick Water and Yarrow Water;

• the majority of sites were classified as JNCC group B - Meso-eutrophic

rivers flowing predominantly over sandstone and hard limestone; • the river is modified in many places by the old rail line. This has altered

the plant community locally, mainly at site with bank protection, where bryophytes now dominate on old rip-rap. Immediately downstream of bridges mid-channel bars have developed which sustain a flora equivalent to that on natural side bars; and

• the Batrachion Ranunculus community is especially sensitive to disturbance

at sites upstream of site 37 where assemblages contain only one or two plants.

4.3.5 Otter

The 2002 survey recorded over 30 sprainting sites and two lying up sites on the River Tweed, Gala Water, River North Esk and Cakemuir Burn. In 2005, evidence for the presence of otters was widespread throughout the Gala Water and its tributaries (see Annex G). The survey data are presented in Annex G.

Table 4.4 Summary Results of Otter Surveys

Otter Signs Number of sites Otter spraints 96 Otter couches 7 Otter holts 5 Otter footprints 5

Figure 4.1 identifies those sites where engineering work is proposed within 50 m of otter couches or holts. This includes survey data from 2002.


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Table 4.5 Sites of Proposed Engineering Work Which Are Located Within 50 m of Otter Resting Places

Engineering Site Reference Holt or Couch Object ID (See Annex G) Site 27 Holt 3 (holt spreadsheet) Site 39 Couch 3 (couch spreadsheet) Site 41 Couch 5 (couch spreadsheet) Site 42 & 43 Holt 5 (holt spreadsheet) Site 42 & 43 Couch 6 (couch spreadsheet) Site 35 & 36 Couch? Data from 2002

Thus, six otter resting sites are potentially at risk from destruction, damage, or disturbance.

4.3.6 Atlantic Salmon

Overview

The River Tweed has been selected as an SAC as it supports a high quality salmon population in a river which drains a large catchment on the east coast of the UK, with sub-catchments in both Scotland and England. The Tweed is the best example in Britain of a large river showing a strong nutrient gradient along its length with oligotrophic conditions in its headwaters, and nutrient rich lowland conditions just before it enters the sea at Berwick. The high proportion of the River Tweed accessible to salmon, and the variety of habitat conditions in the river has resulted in the river supporting the full range of life history types found in Scotland, with sub-populations of spring, summer salmon and grilse all being present. The extensive drainage network accessible to salmon has also resulted in the river supporting a significant proportion of the Scottish salmon resource. The salmon catch in the River Tweed is the highest in Scotland, with just over 15% of all salmon caught in Scotland coming from the Tweed. Historically the river suffered from water quality, and access problems for salmon, but work by SEPA (and previously the Tweed RPB), and the River Tweed Foundation has reversed many of these problems by tackling pollution from sheep dip, and easing the passage of salmon passed man made barriers in the river. In addition there is a long history of salmon management on the river being underpinned by monitoring and research. These salmon based projects have been complimented by a series of catchment initiatives, which are also aimed at improving conditions in the river. Habitat Types

In total six habitat types were noted in the Gala Water catchment, which were run; riffle; pool; glide; chute; and broken standing wave. The dominant meso-habitat within the Gala Water is a run representing an average of 46% of the surveyed habitat type extents. Riffles and pools respectively represented 31 % and 10 % of the surveyed habitat type extents. The trends seen throughout the catchment are that runs and riffles decrease; and pools, glides,


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chutes and broken standing waves increases as the catchment area and hence channel size increases. The survey results from the tributaries show that the proportion of riffles is much higher in the tributaries than that observed within the main channel, with a maximum of 67% observed within reach 30. This is consistent with the trends observed in the main channel. Overhanging vegetation was recorded throughout the catchment, with a general increasing downstream trend. Substrates

In total eight substrate types were recorded along the Gala Water catchment, which were silt; sand; small and large gravel; cobbles; boulders; bedrock and artificial. Dominant and sub-dominant substrates were analysed separately. The percentage dominant and subdominant substrates for each surveyed reach are presented in detail within Annex I. The majority of the surveyed catchment substrate is dominated by cobble (51%), and large gravel (27%). The major subdominant substrate recorded was large gravel, which was recorded at 44% of habitats, with cobbles and small gravel recorded as the subdominant substrate at 18% and 15% of habitats respectively. An artificial substrate (ie concrete) was recorded for 2% of the reaches, which corresponds to a bridge apron within reach 46 and the artificial channel downstream of the cauld in Galashiels (reach 47). The downstream trends observed within the catchment were as expected within the dominant substrates; the extents of cobbles and boulder increase as the catchment size increases and the extents of small and large gravels decrease. The trends observed in the sub-dominant substrate were also as expected with substrate extents of large gravels, cobbles and boulders increasing and the extents of small gravels decreasing. Sand and silt were only present in small amounts and were only found within localised areas of the catchment, predominantly in the upper reaches. Natural erosion/deposition and engineered/anthropogenic features

For the purposes of this assessment, natural and engineered features were analysed separately. Within the main channel of the Gala Water, 24 % of the surveyed reaches had evidence of erosion on one of the banks, and 21 % had deposition along either the bank or within channel. The artificial features recorded within the catchment were a combination of river bank protection measures (ie sheet and wood pilling, gabions, rip-rap, concrete, laid stone and tipped debris) and others such as fords and poached banks. A total of 3.4 km of river bank had some form of bank protection which constitutes 20% of the surveyed reaches. The highest recorded protection type was rip-rip which extended along almost 2 km of the surveyed reaches. The remaining protection works consisted of laid stone (700 m), concrete (300 m) and wood protection (200 m) respectively. Poached river banks represented 500 m of the total reach length surveyed (16.6 km) and 10 fords were recorded (covering more than 50 m).


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Habitat Suitability for Salmon Lifestages

The calculation of the percentage lengths of optimal, sub-optimal and marginal salmon spawning habitat for each survey reach is presented in detail within Annex I. The extents of suitable salmon spawning habitats are distributed sporadically throughout the Gala Water catchment but with the majority of the survey reach containing some suitable spawning habitat. Reaches containing optimal spawning habitat are generally located towards the top of the catchment, and then occur less frequently within the downstream reaches although there is a particular concentration around Stow (located between reaches 28 and 29). The number of transitions between meso-habitats per 100 m is also presented in Annex I. This shows the catchment wide variance between channel diversity, as represented by the transition density between meso-habitat types is low within the main channel downstream of the confluence with the Heriot Water (from reach 11). The transition density is higher within the tributaries and upstream of reach 11, which is a consequence of the smaller channels within these parts of the catchment. Juvenile Habitat. The calculation of the percentage lengths of optimal, sub-optimal and marginal salmon juvenile habitat for each survey reach is also presented in detail within Annex I. The analysis demonstrate that the majority of the catchment offers suitable habitat for salmon juveniles, with the proportion of optimal habitats increasing downstream. The channel diversity with respect to juvenile habitat is again low within the main channel downstream of the confluence with the Heriot Water. Barriers to Migration. None of the weirs, bridges and other features recorded in the catchment currently act as a barrier to salmon migration, therefore it can be assumed that all of the Gala Water catchment is accessible to Atlantic salmon. Summary

The baseline surveys for potential habitat within the catchment have demonstrated that: • Potential Atlantic salmon spawning habitat is distributed in small extents

throughout the catchment, with optimal habitat found at only 15 of the 36 surveyed reaches towards the top of the catchment, and generally comprising of less than 40% of the reach. It is important that these habitats are protected where possible.

• Potential Atlantic salmon juvenile habitat is widespread throughout the

catchment (at 25 of the 36 surveyed reaches) with the proportion of optimal habitat increasing downstream.


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• None of the surveyed potential barriers to migration (including bridges and culverts) would impede on the distribution of Atlantic salmon, therefore it is assumed that the whole of the Gala Water is accessible.

4.3.7 Lamprey

Spawning Habitats and Migration

Suitable spawning habitat is distributed in small extents throughout the catchment, with many of the survey reaches not containing any suitable spawning habitat. For all but one of the reaches containing optimal habitat, the habitat constituted less than 20% of the total reach. Based on the density of transitions between suitable meso-habitats, channel diversity is low within the main channel downstream of the confluence with the Heriot Water (from reach 11) but higher on the tributaries and upstream of reach 11 as expected due to the smaller channels within these parts of the catchment. The main potential barriers to migration observed within the catchment are the presence of weirs and other artificial structures: • three weirs were observed within the survey reaches;

• two small weirs within reaches 41 and 46; and

• the cauld at Galashiels which has a fish ladder.

A fourth possible migratory barrier was present just downstream of engineering location 25, where a supporting structure for a ford blocks the channel during low flows. Brook lamprey have been found throughout the Gala Water catchment, therefore any current barriers to migration do not appear to impede the movement of brook lamprey through the catchment above the Cauld. The absence of river lamprey within the Gala Water and their presence within the Tweed suggests that the weir in Galashiels does act as a migratory barrier to river lamprey. Juvenile Habitat

The habitat mapping identified 47 possible habitats of which 9 were on the River Tweed. In total, 34 sites were electric-fished. Considering the permanence of the silt beds 16 habitats were associated with the presence of vegetation (either aquatic or riparian); 16 habitats occurred in the margins (due to an slack region of flow); six occurred in a poached bank; six formed part of a collapsed bank; one was in a side channel; and two were associated with the presence of an artificial structure (collapsed walls or riprap). This indicates that few of these habitats are permanent features and therefore could be lost in winter spates. The results of the electro-fishing surveys demonstrated that that the majority of the potential habitats sampled produced only a few lamprey larvae. River Lamprey were identified within one of the habitats on the Tweed, whereas all


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lamprey juveniles within the Gala Water were Brook Lamprey. Based on the abundance classes: • 25 of the habitats were classed as marginal, of which 15 produced less than

1 /m2; • six sub-optimal habitats were identified (half of which produced less than

5 /m2); and • three habitats were identified as optimal, with a maximum of 16.6 /m2

recorded at the highest abundance habitat. When assessing the impact of the engineering works, it will also be important to consider the actual size of each habitat in addition to the measure of abundance, as a large area of poor habitat with low densities can actually hold more larvae than a small area of high density. Considering the actual extent of the habitats all bar one of the habitats with larval densities greater than 5 /m2 were found in habitats of bank length greater than 5 m. On the basis of this analysis, the habitats of importance are within engineering locations 21 (Pirn House); 28 (Killochyet); 35 (Bowshank) and 45 (Balnakeil). Location 14 (Hazelbank) should also be noted but is of lesser importance.

4.3.8 Summary

• Brook lamprey were identified within the Gala Water, River lamprey were identified within one of the habitats on the Tweed but there is no evidence that River Lamprey are present within the Gala Water;

• Potential lamprey spawning habitat occurs in small extents throughout the

catchment, with optimal habitat found at only 15 of the surveyed reaches, and generally comprising less than 20% of the reach extent;

• Almost all the juvenile habitats sampled had a few larvae but only a few

habitats had them in abundance, a pattern matching the outcomes of the previous survey within the Tweed catchment;

• Two of the surveyed habitats on the Tweed produced samples with

greater than one larvae per m2, these are of little significance in the context of the middle Tweed. There are known to be much more productive sites both upstream and downstream, and a great deal of habitat similar to the area around the bridge;

• At the few habitats with high abundances, habitat loss or damage could be

significant at the scale of the Gala Water. It is possible that the high quality habitat sampled during the survey may be a very high proportion (or even all) of such habitat on this river. Key areas in terms of impacts on lamprey populations on the Gala Water would therefore appear to be Locations 21 (Pirn House); 28 (Killochyet); 35 (Bowshank) and 45


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(Balnakeil) based on both abundance and amount of habitat (site bank length). Location 14 (Hazelbank) is of note but is of lesser importance; and

• The populations on the Gala Water appear to be of the non-migratory

brook lamprey and hence loss of high-quality habitat could damage locally restricted populations. However, it is thought that brook lamprey do migrate locally to spawn which would reduce their dependence on any one area.


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5 IMPACT ASSESSMENT

5.1 INTRODUCTION

As discussed within Sections 1 and 2, the Appropriate Assessment determines whether the proposals will result in any impacts that will adversely affect the integrity of the qualifying interests for the site and, if so, that there are special reasons why the development should be permitted to proceed. In this context the integrity of the site is defined as “the coherence of its structure and function, across its whole area, that enables it to sustain the habitat, complex of habitats and/or the levels of populations of the species for which it was classified” (1). This section of the report describes the impacts on the qualifying interests of the River Tweed SAC that are predicted to result from the proposals. This will inform the competent authority when determining whether the scheme will adversely affect the integrity of the qualifying interests of the site.

5.2 ASSESSMENT METHODOLOGY

5.2.1 Overview of Methods

The assessment was undertaken in a number of stages, as follows: • the nature and extent of the required engineering works at a location was

established as a set of the generic engineering processes and associated mitigation (see Annex B);

• the changes (or impacts) that qualifying species would be sensitive to, and

which could result from the engineering works proposed were identified; • baseline surveys were undertaken to establish the status of each qualifying

species at each location; • the areas of the river which would be directly affected (referred to in the

annexes as the local zone) and the surrounding areas (referred to in the annexes as the outwith zone) were identified at each location, and compared with the findings of the baseline surveys to gauge the level of interest of the qualifying interest species in these areas;

• the sensitivity of the qualifying interests to the potential impacts was

established, building on the baseline assessment for each habitat or species;

(1) European Communities (2000) Managing Natura 2000 Sites - The Provisions of Article 6 of the 'Habitats' Directive 92/43/CEE. EC


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• the initial mitigation measures (see above) were reviewed and additional location specific mitigation was identified to reduce impacts to a necessary minimum;

• the expected residual impacts after mitigation were determined in the

areas directly affected by the development footprint (ie the local zone) and in the surrounding area (ie the outwith zone) (see also Annex K);

• the significance of the impacts on the qualifying species and on the

integrity of the site was reported; and • the in-combination impacts expected to occur as a result of all the works

on the Gala Water taken together were reported. The nature and extent of the works are described in Section 3. The status of the qualifying species at each of the engineering work areas is reported in Section 4. The assessment is presented in Section 5.6. The remainder of this section follows these stages and presents the results of the impact assessment. The in-combination assessment is presented in Section 6. The full impacts assessment methodology is presented within Annex K.

5.2.2 Evaluation Criteria

The significance of effects on the qualifying interest was assessed according to the following primary criteria: • the magnitude of the residual impacts, as determined by their intensity

and extent in space and time. This takes into account the vulnerability / sensitivity of the habitat or species to the change caused by the development and its ability to recover; and

• the value, in nature conservation and ecological contexts, of affected

receptors including the qualifying species, their populations, communities and habitats.

Significance is determined by the interaction of these primary criteria, being high for large effects on receptors of high value, and lower or insignificant for smaller effects on receptors of lower value (see also Section 5.2). Further details are contained in Annex K.

5.3 POTENTIAL IMPACTS

The engineering works described in Section 3 have the potential to result in a variety of impacts (referred to as environmental changes in Annex K) to the Gala Water and the SAC qualifying interests it supports. These could include: • loss of species (instream or riparian zone);


5-3

• loss/degradation of channel diversity; • disturbance of river bed substrate; • loss of habitat including bankside, riparian or submerged habitat; • loss or damage to otter shelters in the form of underground holts and

above ground couches (1); • disturbance associated with movements of vehicles, operation of

machinery and people and a consequent disruption to normal animal behaviour;

• changes in flow regime (local or wider scale); • barriers to movement or migration of fish (physical and flow velocity) and

movement of otters; • increased suspended solids (sediment); • pollution (hydrocarbons, metals, paints); and • risk of casualties if animals attempt to cross the operating railway and are

hit by a train.

5.4 SENSITIVITY ASSESSMENT

5.4.1 Qualifying Interests

Overview

The qualifying habitats and species are sensitive to the potential impacts described in Section 5.3 to varying degrees. This section describes the sensitivity of each feature to these impacts. CB Communities

The sensitivity of Batrachion: Ranunculus is summarised in Table 5.1. The different contributing macrophyte species are sensitive to different impacts and some species/groups have populations which are inherently more stable than others in the Gala Water. Their sensitivity will also differ with location, for example, above Site 37 few plants occur and would not be easily replaced if lost, whilst at downstream sites there are significantly more plants at sites and the population could rapidly recover from the temporary loss of a few plants. The sensitivity of macrophytes to impacts from the scheme proposals is discussed in more details within Annex G. Otter

It is assumed that the Gala Water provides good otter foraging habitat along its entire length, based on the information on fish populations (see Section 2). Under the Habitats Regulations a licence is required to undertake any works that could disturb otter within 30 m of their places of shelter (holts and couches). A more precautionary approach has been taken in this assessment assuming that all holts or couches that lie within 50 m of proposed engineering works are considered sensitive.


5-4

Atlantic Salmon

The sensitivity of salmon to possible impacts of the scheme is discussed in Annex I in detail and are summarised within Table 5.1. The impacts are considered for all freshwater life stages, but salmon are most vulnerable to disturbance during spawning and hatching, which occurs between November and May (1).

Lamprey

The sensitivity of lamprey to possible impacts of the scheme is discussed in Annex J in detail and are summarised within Table 5.1. Lampreys are susceptible to disturbance at any stage during their life cycle. They are most sensitive to disturbance during spawning and hatching, which occurs between April and June (SNH, 2004). However, lamprey juveniles reside within marginal silt beds for up to seven years and hence the direct disturbance of the juvenile habitats may have a very significant impact on the integrity of the Lamprey populations within the Gala Water.

Table 5.1 Sensitivity of CB Communities and Qualifying Fish Species

CB Community overall sensitivity

Atlantic Salmon Spawning

Atlantic Salmon Juveniles

Atlantic Salmon Migration

Lamprey Spawning

Lamprey Juveniles

Lamprey Migration

Local removal of species Instream disturbance

high high high medium high medium medium

Distrubance of banks

medium low low low low medium low

Physical disturbance of habitats Loss / degradation of channel diversity

high high high high high high high

Disruption of river bed substrate

high high high low high high low

Loss of wetted perimeter

high medium medium medium medium high medium

Loss of riparian vegetation (food source, cover and shade)

high medium medium medium medium medium medium

Loss of submerged vegetation medium medium medium medium medium medium Changes in flow regime (large scale)

high high high high high high high

Changes in high medium medium medium medium medium medium

(1) SNH, 2004. Guidance for Competent Authorities when dealing with proposals affecting SAC freshwater sites. Scottish Natural Heritage.


5-5

CB Community overall sensitivity

Atlantic Salmon Spawning

Atlantic Salmon Juveniles

Atlantic Salmon Migration

Lamprey Spawning

Lamprey Juveniles

Lamprey Migration

flow regime (local) Barriers to migration (physical and flow velocity) n/a n/a n/a high n/a n/a high Over deepening of channel (oxygen depletion)

high high medium Low high medium Low

Sediment pollution Deposition of fines

high high medium N/A high medium N/A

Increased suspended solids

high high medium medium high medium medium

Reduced aq. water quality Acute - hydrocarbons

medium / low

high medium medium high medium medium

Acute - metals

high / medium

high medium medium high medium medium

Chronic - herbicides

high high medium high high medium high

Chronic - organic (nutrient enrichment, DO depletion)

high high medium high high medium high

5.4.2 Site Sensitivity

The risk of effects on the integrity of the SAC occurring at specific locations are greatest at locations where significant residual impacts could occur on qualifying interests of high value. The highest sensitivities were identified in areas directly affected by the proposals (ie the local zone). These are summarised in Table 5.2 and on Figures 5.1 to 5.4. Sensitivities relating to the areas surrounding the directly affected areas are set out in Annex K.

Table 5.2 Engineering Locations where Local Zone Impacts may Contribute to an Impact on the Site Integrity of the SAC.

Loc. Local Zone CB community Otter

salmon habitat sensitivity

lamprey habitat sensitivity

No Extent (m) sensitivity sensitivity Spawn. Juv. final Spawn. Juv. final 6 90 l o h l h h o h 8 170 m o h l h h o h 9 250 o o h l h h o h 10 30 l o h o h h o h 11 180 l o h m h h o h 13 30 l o h h h h o h 14 30 l o h m h h o h 16 30 m o l h h o o o


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17 30 l o o o o o o o 18 130 l o m h h m o m 19 30 o o m h h o o o 20 30 m o h m h h o h 22 90 l o h m h h o h 23 30 m o o o o o o o 24 135 l o m m m o o o 25 30 l o m h h m o m 26 30 m o m h h o o o 27 250 m o h h h h o h 28 170 m o h h h h m h 29 420 l o h h h h o h 30 30 l o o m m o o o 31 30 l o h m h h o h 35 120 l h m h h o l l 36 n/a m h n/a n/a n/a n/a n/a n/a 37 620 l o l h h o m m 38 n/a m h n/a n/a n/a n/a n/a n/a 39 30 m o m m m o o o 40 30 l h m h h o o o 41 n/a o h n/a n/a n/a n/a n/a n/a 42 30 l h m h h o l l 46 30 m o l h h o o o 49 30 l o o o o o l l


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Figure 5.1 Sensitivity of the Engineering Locations, with respect to the CB Community, based on the Local Zone Residual Impacts

Note n/a is applied to engineering locations where either the works are outside the natural Gala Water catchment or there are no in-stream works. (© Crown copyright. All rights reserved. Licence No. 100044822)

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Figure 5.2 Sensitivity of the Engineering Locations, with respect to Otters, Based on the Local Zone Residual Impacts


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Figure 5.3 Sensitivity of the Engineering Locations, With Respect To Atlantic Salmon, Based on the Local Zone Residual Impacts


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Figure 5.4 Sensitivity of the Engineering Locations, with respect to Lamprey, based on the Local Zone Residual Impacts


5.5 MITIGATION MEASURES

To help avoid or reduce the effects of the development proposals which may affect the Gala Water river corridor on qualifying interest species of the SAC, a range of mitigation measures have been incorporated into the scheme design. These are listed below. Further details on measures at specific locations are contained in Annex L and Part II of the CoCP:

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• replacing like with like wherever possible to reduce the area of new habitat loss, especially in-stream including minimising the extent of new river bank protection works;

• minimise the area of habitat permanently lost, or to be affected by

construction works, diversions, compounds etc along the bank-side, in the riparian zone and in-river;

• the existing dimensions of in-river structures (below mean river level) will

be retained to reduce the loss of channel diversity, minimise barriers to fish passage and changes to flow regimes;

• minimise the duration of all construction works which may affect the in-

stream parts of the river including construction compounds, laydown areas and access roads, and restrict the in-stream works to the period between July and October to avoid impacts to SAC qualifying interest fish species;

• construction vehicles will use existing access roads wherever possible to

minimise the effects on habitats and species. Where access has to occur, measures will be taken to ensure the stability of the river banks and the riparian zone,

• the use of heavy machinery in-river, and on the river/bank interface will

be minimised by working from the upper parts of the river banks and from railway embankments, for example by using concrete pumps and cranes to deliver materials, and scaffolding hung from the bridge deck for masonry repairs;

• where in-river diversions are used, they will be designed to prevent the

generation of upstream or downstream scouring, • the design of the new culvert will follow guidance from the Scottish

Executive to ensure the free passage of fish; • hydraulic resting places for fish shall be included in and downstream of

any culvert sections; • areas of habitat adjacent to the proposed works will be fenced off to

prevent incursion into them by construction vehicles and/or personnel, and reduce the risk of loss or disturbance;

• important areas for flora and fauna species will be marked prior to

construction commencing to avoid incursion into these areas. Other measures will be implemented to reduce the risk of impacts on habitats or species including awareness training for contractors;

• all the construction workforce will attend a training session prior to work

commencing so that they are aware of the nature conservation importance of the SAC and its qualifying interest species;

• all machinery working in the vicinity of the river will use biodegradable

lubricants;


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• all machinery operated on site will comply with the relevant noise control regulations and standards, which will assist in reducing the risk of effects on wildlife;

• prior to commencing work all appropriate pollution prevention measures,

including sediment and erosion control, will be installed in line with relevant SEPA’s Pollution Prevention Guidelines (PPGs);

• where de-watering is required from cofferdams or bunded areas, and

subject to an appropriate discharge consent from SEPA, a holding tank will be located on the river bank to ensure settling of sediment before discharge back into the river;

• screening will be used at locations where sandblasting is to occur to

prevent pollution of the river; • where any stockpiling of excavated material is required measures will be

implemented to prevent sediment and run-off from the stockpiles entering the river;

• develop an emergency plan for managing spillages to prevent pollution of

river environment; • the area within the bunded diversions or cofferdams will be cleared and

cleaned of all debris and potential pollution sources prior to them being dismantled, to avoid downstream pollution upon reinstating the river flow;

• disturbed areas will be re-vegetated as soon as practical to reduce the risk

of erosion, and non-vegetative soil stabilisation methods will be used where re-vegetation is not possible;

• where a stretch of river bed is to be re-instated (eg for river diversion and

culvert replacement) locally won material shall be used, for example that excavated from the new channel dug for the river diversion;

• the final surface of rip-rap river bank protection will use local river bed

material and replicate the current diversity of rock sizes present; • SNH and SEPA will be consulted during the detailed design stages of all

proposed engineering works associated with the river environment; and • habitat will be enhanced wherever possible at the sites where river bank

protection works will occur to improve the habitat availability for qualifying species in the longer term.

Further details of mitigation measures are contained the local level impact assessment in Annex K and in the CoCP in Annex M, and further details on the habitat enhancement opportunities at the river bank protection sites are contained in Annex L.


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5.6 RESIDUAL IMPACTS

5.6.1 Introduction

The following sections assess the significance of the impacts of the development proposals along the Gala Water on the qualifying interest species of the River Tweed SAC, using the approach described in Section 5.2 and set out in more detail in Annex K. As the integrity of the SAC is to be considered in its entirety, this assessment considers the overall impact along the Gala Water. Further details of the impacts at specific locations are provided in Annex K. The sensitivities of the species and the locations have been assessed in Section 5.4, and the assessment is based on the scheme including the mitigation measures listed in Section 5.5. The impact magnitude is greatest on the qualifying interests within the local zone, as full mitigation is not always possible, and both permanent and temporary effects will result to qualifying interest species where in-river working takes place (ie in 29 out of the 49 proposed development locations along the Gala Water). The other 20 locations are either not directly located on the Gala Water or a tributary (10 locations), or have no requirement for instream working (10 locations) (see also Section 3). Whilst the magnitude of the impacts in the areas surrounding the development sites (ie in the outwith zone) in any location may be smaller than in the areas directly affected, the value of the species in the surrounding area may be significantly higher. Hence the greatest impacts may occur in the areas surrounding the works sites, for example to the CB community species and the habitat supporting juvenile lamprey, both of which occur infrequently in discrete areas.

5.6.2 Assessment

Annex I: CB Community Habitats

The Gala Water supports a diverse macrophyte community and both the diversity and abundance towards the lower reaches of the river (see Chapter 4). The main impacts on CB habitats will be from the bank protection works and to lesser extent the bridgeworks. No important CB communities were identified in the areas to be affected by the river diversion proposals near Heriot, and the culvert also near Heriot is a dry channel designed to provide flood relief and hence does not support CB communities. Whilst potentially the greatest source of impact two factors help to reduce the likely effects: • approximately 720m (ie 25%) of the bank protection works will be set back

from the river bank which is the best option for protecting the CB communities, and has been adopted wherever possible, as it does not involve any direct in-stream disturbance;


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• bank protection works will only occur at locations which currently contain some existing bank protection works which:

• reduces the scale of the works required; • reduces the areas of previously undisturbed habitat affected; and

• apart from the old riprap (where a lack of soil has prevented successful

colonisation) artificial banks have already been colonised by a range of common plant species of a composition similar to that of the natural banks, which do not contribute substantially to the overall CB communities (see Section 4 and Annex G), and are likely to recover relatively easily following completion of the works.

On the assumption that all plants will be lost within a area extending 3 m into the river within the area directly impacted by the river bank protection works (ie the local zone), the loss of Ranunculus plants is predicted at only two of the 14 locations (Whitelee House (ID Location 38) and Buckholm North (ID41)). This reflects the sparse and patchy nature of Ranunculus distribution in the Gala Water, and at these locations only a single plant will be lost from Whitelee House and the vast majority of Ranunculus plants at Buckholm North occur downstream of the works. Both locations are also in the lower reaches of the catchment where the instream flora is characterised by a greater number of plants compared with the upstream locations. The loss of these plants will not significantly alter the Ranunculus community at these two locations, nor will it affect the distribution, extent or viability of the CB community in the Gala Water as a whole. Other higher plants and bryophytes found within the areas to be directly affected are all common throughout the catchment and/or of lower nature conservation value, and no significant impacts to species or communities are not predicted. The bank protection works have the potential to introduce sediment into the river which may affect plant communities in the waters surrounding the works, although mitigation measures will be implemented to control sediment dispersion (see Section 5.5). The Gala Water is a dynamic watercourse, and it is likely that any sediment generated that does find its way into the surrounding water will be removed rapidly by natural flushing, except possibly during periods of low summer lows. Ranunculus is not normally particularly sensitive to this form of siltation because it tends to inhabit fast flowing areas. However, in the Gala Water it is often found toward the edge of the channel in slower flowing water, and may be more susceptible to siltation than normal. Instream macrophyte populations of particular importance occur in areas adjacent to the river protection works at the following locations: • riprap and concrete retaining wall at Haltree (ID 11);


5-15

• sheet piling and rip-rap at Mill Bank 1 (ID 27); • rip rap at Mill Bank 2 (ID 28); • riprap at Bowshank South (ID 35); • riprap at Bowland (ID 37); • sheet piling and riprap berm (remotely installed) at Whitelee House (ID

38); and • sheet piling and riprap berm (remotely installed) at Buckholm North (ID

41). The following mitigation measures will be implemented to reduce the risk of impacts to the macophyte communities in these areas (see also Location Specific Mitigation Measures in Part II of the Code of Construction Practice (CoCP) in Annex M): • the locations and extent of the communities will be marked on all

construction drawings, and contractors will be made aware of the locations during their awareness training;

• temporary in-river sediment fences (geotextile type material) and/or

bunding will be installed to protect plant communities downstream of the proposed works, and both the plants and fences will be monitored by an appropriate specialist at a frequency agreed with SNH to ensure the plants remain healthy and that the fences are cleaned;

• monitoring of plant communities upstream of the works during the

construction period by an appropriate specialist at a frequency agreed with SNH;

• install bunding/cofferdams where significant in-river works are required

and/or where the works are in close proximity to a significant CB community (1) ; and

• where rip-rap is required the design includes for re-vegetation of the

surface (above the low flow water level) by infilling areas with topsoil (including measures to ensure release into the river is minimised) and seeding with local seeds and/or planting with local riparian vegetation has been included within the design.

Specific location options for bank protection are described within the relevant impact proformas (see Annex K). There are 28 existing bridges and one culvert which will undergo remedial repairs. The culvert is to be renewed but is offline, on a flood relief channel that was dry at the time of the survey and contained only terrestrial vegetation. Pre- and post scheme dimensions of the footprints of the bridges

(1) The option for bunding all river bank protection works to create a dry working environment at each was considered but the impact of construction of the bunds together with the unknown influences of the temporary changes in hydraulic

regime were thought to outweigh the benefits.


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and the culvert will not be greatly affected by the development proposals; hence the impacts to the CB communities will be restricted to the areas associated with the temporary construction works including any in-river diversion works required. The areas directly affected by the bridge works contain only single plants of Ranunculus penicillatus pseudofluitans at the following locations: • Ferniehirst Water Underbridge (ID 31); and • Torwoodlee Water Underbridge (ID 42). The CB community can withstand the loss of these plants assuming the rest of the Ranunculus at these locations is unaffected. The other plants which occur most often within the areas to be directly affected by the bridgeworks are Fontinalis antipyretica and Rhynchostegium riparoides, both of which are ubiquitous species. The loss of these plants from within the works areas will have a negligible effect on their populations within the Gala Water. De-vegetation of the bridges will be required to allow re-pointing. However, this will only require localised removal of plant species. So whilst considerable loss of bryophytes will occur, the de-vegetation will not affect any CB communities and hence not affect any qualifying interest species of the SAC. Macrophytes communities, which make a significant contribution to the overall CB community of the SAC, are present in the waters surrounding bridges at the following locations (especially IDs 10 and 33): • Little Gala Underbridge (ID 10) which has an isolated but very healthy

Callitriche population which is larger than Callitriche populations at other locations, and is probably the most important source of Callitriche seeds and fragment propagules in the Gala Water;

• Watherston Underbridge (ID 25); • Gala bank Underbridge (ID 26); • Lugate Bridge Underbridge (ID 30); • Ferniehirst Water Underbridge (ID 31); • Bowshank North Underbridge (ID 33) where Ranunculus plants occur both

upstream and downstream of the bridge location; • Bowshank South Underbridge (ID 34); • Harper’s Culvert Underbridge (ID 36); • Whin Water Underbridge (ID 40); • Torwoodlee Water Underbridge (ID 42); • Ryehaugh Water Underbridge (ID 45); • Kilnknowe Underbridge (ID 46); and • Red Bridge Underbridge (ID 49).


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In-river works are not required at the Bowshank underbridges, Harper’s Culvert and Ryehaugh Water and hence CB communities will not be affected. At the remaining sites the relevant mitigation measures set out in Section 5.5 and in the CoCP (see Annex M), will be implemented to ensure that impacts to the CB communities are negligible. Other plant species of nature conservation interest found at the bridge locations include a number of bryophyte species: Brachythecium rivulare, Amblystegium fluviatile, Chiloscyphus polyanthos and Fontinalis squamosa. With the exception of F. squamosa at Red Bridge (ID 49), all are found outwith the areas to be directly affected and their populations should not be damaged significantly. The work at Red Bridge is very minor and the patch of F. squamosa should not be affected as it is not close to the bridge supports. The plants which occur most often within the defined local zones of impact for the bridges are Fontinalis antipyretica and Rhynchostegium riparioides. Both are effectively ubiquitous. The loss of these plants within the works area will have a negligible impact on their populations within the Gala Water. Annex II Species: Otters

The British stronghold of otter is in Scotland. The National Survey of Otter Distribution in Scotland (2003 – 2004) (1) included the River Tweed SAC, which was surveyed between September and November 2003. Sites were randomly selected from the River Tweed and its main tributaries including the Gala Water. In total 187 sites in the SAC were visited. The survey findings confirmed that otter had expanded and consolidated its range within the Tweed catchment and had occupied a number of previously peripheral sites. The findings also confirmed that the River Tweed SAC had maintained favourable status for otter as a feature of the catchment and that there is an abundance of fish prey in the catchment which supports the otter population, the fish biomass is particularly good within the lower reaches. Overall the national survey concluded that otter has continued to increase its population and range throughout Scotland. The baseline surveys for the Waverley project conducted in 2005 found that otters continue to be widespread throughout the Gala Water and its tributaries (see Section 4.3.5 and Annex G). The surveys (including those from 2002) recorded six otter sites within 50m of the proposed work areas (see Table 5.3).

Table 5.3 Sites of Proposed Engineering Work Which Are Located Within 50 m of Otter (2005 and 2002 surveys)

Engineering Site Holt or Couch Object ID (see Annex G)

Mill Bank 1 RBP (ID 27) Holt 3 (holt spreadsheet)

(1) National Survey of Otter Lutra lutra Distribution in Scotland 2003-2004. SNH 2005.


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Whitelee House RBP (ID 38) Couch 3 (couch spreadsheet)

Buckholm North RBP (ID 41) Couch 5 (couch spreadsheet)

Torwoodlee Water Underbridge and Torwoodlee Flood relief Culvert Underbridge (IDs 42 and 43)

Holt 5 (holt spreadsheet)

Torwoodlee Water Underbridge and Torwoodlee Flood relief Culvert Underbridge (IDs 42 and 43)

Couch 6 (couch spreadsheet)

Bowshank South RBP (ID 35) and Harper’s Culvert Underbridge (ID 36)

Couch? Data from 2002 survey

All of the shelter sites in Table 5.3 except the holt at Mill Bank 1 (ID 27) lie within the areas to be directly affected, and it is assumed that they will be lost to the proposals. The holt at Mill Bank 1 lies approximately 50 m from the works and will not be significantly affected. This loss of one holt and up to four couch sites will require an application to be made to the Scottish Executive for a relevant licence at an appropriate time. Where the holt is to be lost at Torwoodlee, two artificial holts will be constructed in suitable locations nearby in locations which will not be subject to disturbance from the proposals. Subject to a licence approval these artificial holts will constructed at least 6 months prior to the loss of the existing holt, to allow the animals time to adjust to them. Otters are known to occur at low population densities in freshwater habitats and have home ranges which cover great distances (ie in the order of 20-30 km). As a result they often travel large distance to feed in any one night (ie 16 km or more). Given the development works occurring along the Gala Water it is possible that some disruption to their foraging paths could occur. However, in freshwater habitats otters are largely nocturnal and hence it is likely that much of the animals’ activity will occur at times when there is little or no construction work taking place as work will cease at dusk (see Annex M). Some disruption is likely to otter passage near Heriot (ID 6) where the river diversion works will occur. However, given the diversion requires the creation of a new channel to the west of the current alignment, and work on this can take place without much effect on otters. The main impacts are likely during the joining of the new river section and closure and infilling of the existing section, all of which will be of short term duration and are likely to occur during daylight hours. Hence significant impacts to otters are not predicted. The project design will incorporate measures to help maintain the passage of otters along the river, by minimising the impacts to established paths, and including otter ledges along the bridges to enable movement to continue during periods of high water flow. During the construction works any pipes used will be capped to prevent otter gaining access to them when contractors are off-site, and any the length of open trenches will be restricted with a series of parallel planks used to facilitate crossing if required. Planks will also be placed at a 45° angle to allow animals to escape should they enter the trenches.


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Measures to protect the Gala Water from pollution during the construction and operation of the railway have been set out in Section 5.3 and the CoCP (see Annex M). The implementation of these measures will serve to protect otters from pollution and also its fish prey species. In summary the development proposals will affect otters along the Gala Water. However, the mitigation measures will be implemented to provide new holts to replace those lost, to help maintain as much existing habitat and the passage of otters, and to avoid pollution of the watercourse. As otters are a highly mobile species a further survey will be undertaken prior to works commencing to check for any changes in their status and distribution and continued consultation with occur with SNH. Annex II Species: Salmon

The majority of the Gala Water and the tributaries are productive salmon recruitment grounds (see Section 4.3.6 and Annex I). The timing of the works between July and October inclusive will ensure main effects on salmon will be a temporary loss of habitat due to physical disturbance during the construction period. By virtue of their extent these impacts will be most significant in the vicinity of the river bank protection works. Based on the Centre for Ecology and Hydrology’s (CEH) digital rivers data (1), the total length of the main channel and all tributaries within the Gala Water is 291 km, of which the baseline studies surveyed 16.92km (2) . Analysis of the temporary loss of habitat within the areas directly affected has been assessed in the context of the potential spawning and juvenile habitat within the whole catchment and was found to be low within all habitat value classes (see Table 5.1). This analysis assumed that only 50% of the total channel length within the catchment provides suitable habitat for salmon of the quality identified within the survey reaches. Hence the physical disturbance within the areas directly affected is very unlikely to adversely affect the integrity of the Gala Water with respect to salmon.

(1) Derived from the 1:50 000 Ordnance Survey map data. (2) Based on the Centre for Ecology and Hydrology’s digital rivers (derived from 1:50,000 Ordnance Survey (OS) map data).


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Table 5.1 Analysis of Habitat Loss for Atlantic Salmon Habitat Class

Optimal Sub-optimal Marginal Unsuitable Missing Data (1)

Salmon Spawning

surveyed extent (m) 1148 3834 2559 8643 743

Habitat density (m/km) 68 226 151 511 0

total productive habitat (m) 9870 32956 21995 74296 0

extent in local zone (m) 369 731 472 5 0

loss of productive length (%) 4 2 2 0 0

Salmon Juvenile

surveyed extent (m) 3195 6653 824 5512 743

Habitat density (m/km) (2) 189 393 49 326 44

total productive habitat (m) (3) 27467 57189 7082 47380 0


loss of productive length (%) 2 3 2 0 0

The length of water in the areas surrounding the directly affected areas totalled 18.5 km (ie the total outwith zone stream length), which is a factor of 5.9 greater than the total extent of the local impact zone. However, mitigation measures, including timing of the works (see below), will be implemented to ensure that the effects on spawning and juvenile habitats in the surrounding areas will be low, and are not likely to adversely affect the integrity of the Atlantic Salmon populations within the catchment. The construction works in any one year will be restricted to the months of July to October inclusive. This will avoid the migration period and hence the works will not provide any temporary barriers to migration. As the construction period will extend over a number of years the disturbance at locations will also be staggered over the construction period, reducing the overall impact along the river at any one time. The seasonal restrictions will mean that only salmon juveniles will be in the catchment while construction work is occurring, and whilst they will be sensitive to excess suspended sediment and other residual impacts in the surrounding waters, juveniles are mobile and will not be unduly compromised by the works. Mitigation measures will also be implemented to help control sediment dispersal (see Section 5.5 and Annexes K and M), and any deposited sediment is likely to be quickly mobilised during higher autumn flows before the adults return to spawn. The majority of the existing bridges have wide open spans and do not appear to represent a barrier to migration, as demonstrated by the presence of salmon

(1) Parts of the surveyed reaches that were too deep to survey safely (Red Bridge on Tweed at Location 49 and within the lower reaches of the Gala Water at Kilnknowe (ID 46). (2) Based on dividing the total class lengths surveyed by the total length of survey. (3) Based on re-scaling the habitat densities by 50% total stream length for the Gala Water catchment to represent potentially lower habitat suitability within the very small headwater catchments of the tributaries.


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within the upper catchment reported in previous studies (see Section 2) and Annex I. As the in-river dimensions for bridges will not change as a result of the proposals no change in this situation is predicted. The river diversion works within the headwaters near Heriot (ID 6) require the diversion and culverting of a significant stream length, and are expected to impact on the full width of the river. However, the baseline surveys have demonstrated that the habitat within the vicinity of these locations is of relatively poor quality and significant impacts on salmon are not predicted. The scheme has the potential for construction-related noise and vibration impacts to fish in the Gala Water. The main potential impact would be from driving of piles in the river which has been recorded as generating high levels of underwater noise (1). In-river piling will be required in two locations in the Gala Water (see Section 3). A study assessing the potential effects of pile driving activities on the behaviour and distribution of schools of juvenile pink (Onchorynchus gorbushca) and chum (O. keta) salmon in Puget Sound, Northwest United States (2) observed a number of impacts which are summarised below. • within the range of salmonids hearing, the sound field generated by pile

driving activities had a radius of at least 600 m; • nearly twice as many fish shoals were found on the construction side of

the site on non-pile driving days compared to driving days; • fish shoal distances from shore did not change significantly as a result of

pile driving; and • stomach content analysis indicated that most fish were feeding. A further study documents monitoring measurements of waterborne noise resulting from impact piling and vibropiling at Town Quay, Southampton, during construction operations. At the same time, the reactions of caged farmed brown trout (Salmo trutta) was observed on CCTV equipment to determine whether there was any observable effect of the piling on the their behaviour. The caged trout monitoring revealed: • no evidence that trout reacted to impact piling at a range of 400 m; • no evidence that trout reacted to vibropiling at even a close range of less

than 50 m; and • no evidence of gross physical injury to trout at the monitoring range of

400m. In respect of the vibropiling, noise levels from this activity were not audible at the monitoring site, which was 417 m from the works.

(1) Abbott & Bing-Sawyer (2002) cited in Nedwell J., Turnpenny A., Langworthy J and Edwards B. (2003). Measurements of underwater noise during piling at the Red Funnel Terminal, Southampton and observation of its caged fish. Subacoustech Report Ref 558 R 0207. (2) Feist, Anderson & Miyamoto (1992). Potential Impacts of Pile Driving on Juvenile Pink and Chum Salmon Behavior and Distribution. University of Washington, School of Fisheries.


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The studies referenced above suggest that salmon species may exhibit “startle” and general avoidance behaviour in response to construction noise and vibration sources such as piling within 400m. No evidence however, of gross physical injury to fish at a monitoring range of 400m was observed in the above studies, and although internal injury may be possible to a fish in close range to an operating pile-driver, the general avoidance behaviour observed would indicate that shoals would move away from the construction area, thus avoiding physical harm. The area of disturbance of any potential noise impacts is unlikely to extend beyond 600m up and downstream from any noise and vibration source (construction site) and the resulting potential habitat loss (resulting from avoidance behaviour) during operations is considered minimal. In view of the transient and localised nature of the operations residual impacts are not expected to be significant. The only expected residual impact is temporary avoidance of feeding areas and restriction in up/downstream movement during periods of peak construction activity ie piling operations. The works will however be undertaken outside periods of spawning and migration. Annex II species: Brook Lamprey

The timing of the works between July and October inclusive will ensure that the main effects on lamprey will be a temporary loss of habitat due to physical disturbance during the construction period. By virtue of their extent these impacts will be most significant in the vicinity of the river bank protection works. In the areas directly affected two impacts need to be considered: • the temporary disturbance of spawning habitat; and • the permanent loss of abundant juvenile habitat. Analysis of the temporary loss of spawning habitat for lamprey has been assessed using the same approach used in the assessment of impacts on salmon (ie in the context of the potential spawning habitat within the whole catchment), and was found to be low within all habitat value classes (see Table 5.2). Hence the physical disturbance within the areas directly affected is very unlikely to adversely affect the integrity of the Gala Water with respect to lamprey spawning habitat .

Table 5.2 Analysis of Spawning Habitat Loss for Lamprey

Spawning Habitat Class

Optimal Sub-optimal Marginal Unsuitable Missing data

Surveyed extent (m) 986 1700 39 13460 743

habitat density (m/km) 58 100 2 795

total productive habitat (m) 8472 14614 334 115697


loss of productive length (%) 3 2 6 0


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The impacts on juvenile habitat require a different approach, as the juveniles live within silt beds in the margins and close to well oxygenated flow (see Section 4 and Annex J). These silt beds are very sensitive to physical disturbance and are likely to be lost if they occur within the areas directly affected. Juvenile habitat will be lost from the following areas: • Mill Bank 2 (ID 28) - an area of 12.2m2 of sub-optimal habitat; • 81 Bowland (ID 37) – an area of 2 m2 of sub-optimal habitat; and • 81 Bowland (ID 37), Torwoodlee Water Underbridge (ID 42) and Red

Bridge Underbridge (ID 49) – a total area of 93.4 m2 of marginal habitat. There is no loss of optimal juvenile habitat and the loss of these sub-optimal and marginal habitats is small and not likely to affect the integrity of the lamprey population within the catchment. In contrast there is a significant amount of optimal and sub-optimal juvenile habitat in areas surrounding those directly affected as follows: • Hollowshank Underbridge (ID 14) - 4.7 m2 of optimal habitat; • Mill Bank 2 RBP (ID 28) - 9.8 m2 of optimal habitat; • Plenploth North Underbridge (ID 19) – 25.1 m2 of sub-optimal habitat; • Mill Bank 1 RBP (ID 27) - 2.8 m2 of sub-optimal habitat; • Whitelee House RBP (ID 38) - 62.5 m2 of sub-optimal habitat; • Ryehaugh Water Underbridge (ID 45) – 29.4 m2 of sub-optimal habitat;

and • Red Bridge Underbridge (ID 49) - 10.5 m2 of sub-optimal habitat. Of these only the juvenile lamprey habitats at Mill Bank 2 RBP (ID 28) are within close proximity of the works, but are upstream. Mill Bank 1 RBP (ID 27) and Whitelee House RBP (ID 38) are on the opposite bank to the works and the remaining habitats were not in close proximity to the works. The significance of any impacts to the optimal and sub-optimal habitats in the surrounding waters is predicted to be low, given the generic and location specific mitigation which will be implemented (see Section 5.5 and Annexes K and M). Given the sparse nature of optimal habitat within the catchment these areas are particularly important to the integrity of the Lamprey population in the Gala Water and the SAC and, therefore, an appropriate specialist will monitor the impact of construction on these habitats. The construction works in any one year will be restricted to the months of July to October inclusive. This will avoid the sensitive adult and ammocoetes (1) migration and spawning periods and hence the works will not provide any temporary barriers to migration. As the construction period will extend over a number of years the disturbance at locations will also be staggered over the

(1) Larval and juvenile lamprey.


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construction period, reducing the overall impact along the river at any one time.

5.6.3 Operational Impacts

The trains that will be used on the tracks are Diesel Class 158 or 170 which will begin service at 0530 hours and finish at 2330 hours each day, with four train movements an hour (two in each direction). Currently, it is envisaged that no freight trains will use the rail line. The operational railway will have no direct impact on the Gala Water. Indirect effects may result from discharges from the operating trains, drainage from the track especially where old track is reused and regular maintenance activities to keep the track free of ice and leaves. Management of these issues to avoid impacts to the river have been discussed further in see Section 3.3 and are also contained in the CoCP (see Annex M). Under normal working conditions no significant impacts to the river are predicted and response plans will be developed prior to work commencing to control any pollution which might occur in case of an emergency situation. Any noise impacts from the operational railway are not expected to have a significant effect on otter shelters. Of the two holts identified within 50m, one will remain at approximately 50m from the operating line, and the other will be replaced with two artificial holts which will be located appropriately in agreement with SNH, to reduce the risk of significant noise impacts. The project design will incorporate measures to help maintain the passage of otters along the Gala Water, and keep them off the operating railway track (see Section 5.6.2). Underwater noise impacts associated with operational rail networks and pre-operation construction activities, other than pile driving, are not well documented, however, it is considered unlikely that noise levels would be sufficient to trigger a behavioural or avoidance response in fish species. In the event that low levels of noise attenuate (1) from the track to the Gala Water, research indicates that fish may become “conditioned” to the frequent (trains operational for 18h day-1) background noise. Furthermore, any noise levels associated with a passing train will rise and fall as the train approaches and passes, thus further reducing the “startle” reaction potential. Impacts resulting from the operational phase are not considered to be significant. The Promoter has adopted a Noise and Vibration policy which requires that wheel and rail surfaces are maintained to minimise noise impacts. A noise and vibration monitoring scheme will also be in place which will be used to inform maintenance programmes so that any increase in noise and vibration is minimised.

(1) A number of variables including local geology, distance from water body and speed of train will alter the degree of noise attenuation.


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The river bank protection works proposed are designed to protect the existing railway embankments, by ensuring that the erosive forces of the river do not further undermine/scour, firstly the river bank and then the railway embankment to an extent that affects the structural stability of the embankment. The works are generally applied on the river bank itself, apart from a few locations where the option of installing sheet piling remote from the river bank has been adopted, to reduce the impacts on the aquatic environment (eg Gala Water / Shoestanes Burn (ID 4), near Heriot Station (ID 8)(in part), Whitelee House (ID 38) and Buckholm North (ID 41)). At all site the proposed works are to repair/replace existing protection. At some locations there is a minor extension of works proposed but this has been kept to a minimum. These RBP works will reduce the erosion of the river banks, over the sections where they are applied, in two main ways. • preventing direct, frequent scour of bank material causing mass failure -

through dissipation of the potential scour energy of the river by the armouring layer (riprap, sheet piling or concrete retaining wall) and re-profiling of the slope to a more stable angle.

• prevention of erosion of individual soil particles from surface flows over

the bank area and flows parallel to the bank – by promoting re-vegetation on exposed bank surfaces that otherwise may be kept bare by continual scouring by river flows. Where riprap is adopted, re-vegetation will occur over the entire bank surface. The area available for vegetation growth would be restricted to above concrete retaining walls or sheet piling.

Further details on mitigation of potential downstream erosion are contained in Annex M.


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6 CONSIDERATION OF IN-COMBINATION EFFECTS

6.1 INTRODUCTION

Appropriate Assessment is a process required under Article 6(3) of the Habitats Directive (1) for a plan or project which: either alone or in combination with other plans or projects would be likely to have a significant effect on a European Site. Impacts on the ecology and nature conservation of the Gala Water and River Tweed SAC arising from the proposals (including construction) are evaluated in the main body of the report. The in-combination effects of the current development proposals and other proposed projects and plans are considered in this section of the report.

6.2 OBJECTIVES OF THE STUDY

The key objectives of the In-Combination assessment are to: • to identify all plans and projects with the potential to result in significant

impacts on the Gala Water / Tweed SAC in combination with the proposed Waverley line;

• to assess the significance of potential impacts on the Gala Water / Tweed

SAC of the proposed Waverley line in combination with other plans and projects; and

• to determine a course of action in relation to the decision, consent or

authorisation; to affirm, modify or revoke.

6.3 SCOPE OF STUDY

6.3.1 Technical Scope

The Habitat Regulations limit the in combination test to “other plans and projects”. These should include (2): • approved but as yet uncompleted plans or projects; • plans and projects for which an application has been made and which are

currently under consideration but not yet approved by competent authorities; and

(1) Implemented through Regulation 48 of the Conservation (Natural Habitats &c) Regulations 1994. (2) English Nature (2001) Habitats Regulations Guidance Note 4, May.


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• permitted ongoing activities such as discharge consents.

6.3.2 Spatial and Temporal

In view of the above requirements, this assessment has broken the scope into three separate areas, these together with the spatial and temporal scope agreed with Scottish Natural Heritage (SNH) are summarised in Table 1.1.

Table 6.1 Scope of the Assessment

Technical Spatial Temporal Plans, including the local development framework.

5 km buffer along length of affected Gala Water

Lifetime of proposed plan or programme.

Projects, specifically planning applications.

1 km buffer around the Gala Water.

Planning applications received in last 5 years.

Consents and discharges (1) 1 km buffer around the Gala Water.

Current and known likely future consents/discharges

No detailed information regarding present or future discharge consents has been processed. However, the impact of existing discharges on instream water quality has essentially been captured within the baseline water quality information used in the assessment. This has demonstrated that the Gala Water is in A1 status (Chapter 2). Discharges from proposed projects which are in the planning system have been taken into consideration in the assessment.

6.4 LIMITATIONS AND UNCERTAINTY

There are a number of limitations and uncertainties associated with the data that has been collected as follows: • implementation of the plans is not guaranteed – ie proposals in the

development plan may not materialise; and • planning applications – a Completion Certificate issued for building

warrants has been taken as a proxy indictor for completion of project. Searches have identified where a completion certificate has been issued to the same geographical location and extent as the original application, however this only relates to building projects.

(1) Envirocheck from Landmark to determine existing consents and discharges within a 500m buffer along the Gala Water between the river near Middleton Moor in the north and Tweedbank in the south.


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6.5 REVIEW OF PLANS AND PROGRAMMES

6.5.1 Introduction

Table 2.1 provides a summary of local and, where appropriate regional plans that are approved but as yet uncompleted (ie still being implemented) and that may interact with the proposed Waverley rail project. An initial review concluded that the majority of plans encompassing potentially significant works such as mineral workings, waste, transport, renewable energy are primarily strategy focussed, and of little relevance in predicting potential cumulative impacts in conjunction the proposed Waverley Line. Of greatest relevance and significance is therefore the Scottish Border Local Plan. Although presently at the Consultative Draft stage, the plan is a material consideration in determining planning applications. As it approaches adoption the plan gains increased weight in the decision-making process. In view of this, only this plan has been considered in detail.

6.5.2 Scottish Border Local Plan, Consultative Draft, 2005

The Local Plan takes the overall land requirement set out in the Scottish Borders Structure Plan and translates into site specific locations. It also contains the Council’s policies and proposals to guide development in the Scottish Borders until 2011. The current Local Plan is presently at the Consultative Draft Stage, the first stage of consultation is complete, with a second stage of consultation underway between 4th July and 12th August 2005. Observations on the Consultative Draft Plan will be taken into consideration in drawing up the Finalised Local Plan. For the purpose of this review, the development plan allocations proposed in the Draft Local Plan are assumed to be completed in the period to 2011. Annex A provides a review of the Local Plan opportunities / allocations that are considered to be of relevance when considered cumulatively with the proposed Waverley Railway and the potential for effects on the River Tweed SAC.

Table 6.2 Plans and Programmes

Plan or Programme

Objectives or Requirements Potential Impact

Scottish Borders Structure Plan (2001 – 2011)

Structure plan provides the long-term strategic policy framework setting out an overview of development needs in the Scottish Borders, principally for housing and development. Principle S3 sets out the Scottish Borders Development Strategy, aspects of relevance are provided below. • Development to be guided to existing town and villages or to planned locations where readily

accessible to the principal public transport corridors. • The principal focus for development is the primary hub (Central Borders). • Substantial new development within the structure plan period is to be supported in principle in the

following location: east of Galashiels within the Galashiels/Melrose/St Boswells corridor. • Longer term substantial development to be supported in principle in the following locations: 1) the

Newtown St Boswells/St Boswells area, the Galashiels-Selkirk axis, the Peebles/Innerleithen/Central Borders axis dependant on progress on the railway.

• Upgrading and improvement of major road corridors, in particular the A7 and A68. Economic Development • Development of opportunities for timber processing will be encouraged, the location to the guided

by the following principles … accessibility to the strategic road and rail network with preference given to the line of the former Waverley line and the Kielder Branch Line.

General policies within the Structure Plan are non-specific, setting out the need for Local Plan to designate site specific policies and proposals.

Scottish Borders Local Plan, Consultative Draft to 2011

The Scottish Borders Local Plan sets out the Council’s approach to the development and use of land, it is written in compliance with the Scottish Borders Development Strategy. Central Borders Area Strategy noted as area that will see greatest change in the Galashiels/Melrose/St Boswells corridor where land for substantial development to meet the housing land requirement has been identified. Also the area where the possibility of a new settlement has been suggested. Details on allocations for development within the Local Plan are discussed in Section 3. Until the Consultative Draft Plan is adopted a draft interim housing policy guidance (February 2005) has been produced

Plan or Programme

Objectives or Requirements Potential Impact

Scottish Border Woodland Strategy (SBWS) 2005

The Scottish Borders Woodland Strategy sets out policies and proposals for the future of trees, woodlands and forests in the Scottish Borders. The Gala Water is identified along with all other tributaries of the Tweed as a preferred are for woodland expansion. Preferred areas are those classified by the Border Landscape Character Assessment as Lowland River Valley and for native riparian woodland. Areas around Stow and Galashiels are also identified for urban fringe woodland expansion.

Scottish Border Biodiversity Action Plan (BAP)

Local BAP defines objectives and targets for species and management of habitats, Rivers and Burns are identified. Principal aim of the Scottish Border LBAP is for the integrated management of the Tweed catchment to conserve and enhance the natural and economic resources for the communities of the Scottish Borders.

Tweed Catchment Management Plan, November 2003

Seven strategic aims of the Tweed Catchment Management Plan: • Maintain and enhance the water quality of the Tweed Catchment. • Ensure that there is water available for abstraction while protecting the needs of the natural

environment. • Maintain and enhance the status and distribution of riverine, riparian and wetland species, and

habitats of conservation concern. • Ensure all riverworks respect the physical, ecological and aesthetic integrity of the river system. • Adopt a catchment based approach to flood management which helps to protect the people,

property and prosperity of the Tweed Catchment. • Promote the sustainable development of river-related tourism and recreational activities to

accommodate a variety of interests. • Ensure the delivery and development of the Tweed Catchment Management Plan.


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6.6 PLANNING APPLICATION REVIEW

6.6.1 Introduction

In order to determine projects approved, but as yet uncompleted or under consideration by the planning authority, a planning application review was undertaken. This included all planning applications received in the last five years within a 1 km buffer of the Gala Water. A scoping exercise to determine those categories and applications of no relevance to the cumulative impact assessment (conservatories, windows, lighting etc) was undertaken. A list of all categories removed from the search is provided in Annex B. The review identifies all relevant planning applications made to Scottish Borders Council over the last five years (ie approved but as yet uncompleted projects) – from 31st December 2000 to 31st July 2005. Annex C records, the Scottish Borders Council application reference, site location, proposed development description, approval date of application (if approved) and potential for cumulative impacts to the Gala Water and River Tweed. Figures C1 to 4 show the locations and extent of the proposals. It should be noted that the issuing of a completion certificate relates to the building warrant required for all building works. Not all applications require a building warrant, therefore there is not actually a direct link between the issuing of a completion certificate (CCI) and the application actually being constructed. Instead this acts as a crude indicator for completion as it identifies those applications where a CCI has been issued to the same geographical extent as the original application.

6.7 DISCUSSION OF IN-COMBINATION EFFECTS

6.7.1 Overview

The review of in combination effects has been based on the information available from registered planning applications. The planning applications identified by the search criteria are listed within Annex C. The Annex lists the following information: • the application reference number; • a description of the site location; • details of the proposed development; • the date of application approval; and • whether a completion certificate has been issued. The assessment of in combination effects has been based on the types of planning application and the likelihood of impact upon the Gala Water.


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6.7.2 Review of Planning Applications By Type

Prior to conducting a detailed review, applications with completion certificates have been identified and removed as these are already captured in the existing baseline conditions. The remaining 50 applications have been considered in this assessment (see Annex N). These applications have then been classed by type of development as presented in Table 6.3 and only the potential long term impacts which may result listed, as it has been assumed that the approved construction code of practice for each development will contain the necessary mitigation measures required to manage construction impacts.

Table 6.3 Number of Planning Applications By Type

Type Number Causes of Potential Impacts Wind farm 4 Some very localised changes to

ground water may occur and minor enhancement of surface runoff from trackways and hard standing, sediment pollution from trackway erosion, accidental spillage of lubricants and other maintenance material

Housing developments 14 Water supply (if from within the catchment) and effluent treatment, surface water runoff, enhanced car usage and associated heavy metal and hydrocarbon contaminants, increased contact between humans and the river.

Individual dwellings 6 As for housing development but to a lesser degree, potential for septic tank treatment of effluent causing localised pollution.

Light industrial, retail and change of commercial use

11 Pollution arising from commercial activities, increased car activity , quantity and quality of surface water runoff from car parks, potential noise pollution if in proximity to water courses.

Recreational 1 Increased car activity within the vicinity of the development, runoff from car parking.

Quarrying 2 Direct and indirect wash off of sediment into adjacent water courses (physical impact and, potentially, quality impacts), noise pollution,


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Type Number Causes of Potential Impacts Landfill 4 Contaminated leachate and

contaminated runoff from site, debris entering neighbouring water courses, vermin, pollution associated with traffic.

Agricultural 5 Animal waste, leachate from silage, soil disturbance in the vicinity of building, enhanced risk of agrochemical pollution.

Road construction

1 Noise pollution if in vicinity of stream, contaminated road runoff, increased access to riparian zone.

Instream river bank protection works

2 As per river bank protection work discussed for the current scheme.

Potential Impacts

In practice, the potential impacts from small developments are likely to be negligible. Those from the larger should have been considered as part of the environmental impact assessments (EIAs) and design procedures, for example defining appropriate drainage and treatment of road runoff. Housing Developments

Thirteen of the 14 housing development proposals comprise a total of 457 housing units. The 14th proposal is for an outline development and does not specify the number of proposed housing units. These developments represent, potentially the largest impacts within the catchment, but with appropriate mitigation measures and drainage provision these impacts should be mitigated to such an extent that the developments will not adversely affect the qualifying interests. Quarrying

The two proposed quarrying activities are relatively minor in scale and one (01/01172/MIN), lies outside of the Tweed catchment to the north. The second (01/01172/MIN), is a resumption of minor quarrying at the location of a police firing range. Appropriate Assessment for Other Planning Applications

The planning search identified two applications for which an appropriate assessment was requested: • 02/01468/SBC Landfill site, Easter Langlee, Galashiels. This

approved application relates to the extension of a landfill site in proximity to the Allan Water (a tributary of the Tweed confluent downstream of the confluence of the Gala Water with the Tweed). Of the four applications classified as landfill, three relate to this landfill site. The fourth, relates to a


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cemetery extension in close proximity to the landfill site. These applications have been approved and it has , therefore, been assumed that the proposals would not affect the integrity of the SAC.

• 02/00554/FUL Boleside Fishings, Boleside, Galashiels. The

application is for two lengths of riprap river bank protection in the Tweed upstream of Galashiels where erosion issues are thought to be associated with existing river bank protection works. The planning authority has confirmed that this application has not been progressed and hence it has not been considered further in this assessment.

River Bank Protection Works

As well as the river bank protection works previously mentioned upstream of Galashiels, there is a second river bank protection works application. This is the re-issue of a time limited planning application that covers two existing croyes on the Tweed upstream of Boleside and Galashiels.

6.7.3 Distribution of Planning Applications In The Catchment

Overview

The locations and spatial extents of the planning applications listed within Annex C are shown on Figures C1 to C4. These figures include all applications and hence include both ones that lie outside of the catchment of the Gala Water and applications for which completion notices have been served. With the exception of the landfill application, all the other applications lie broadly into two areas: • within the Galashiels area; and • upstream of the Galashiels area. Proposed Development in Galashiels

Of the proposed developments in Galashiels, there are two which relate to major retail developments (03/00347/FUL and 03/00976/FUL). Both proposals are located on the banks of the Gala Water within Galashiels: • the construction of a new road bridge across the Gala Water at Cauld in

the vicinity of an existing pedestrian bridge; • a development which includes an 83 unit housing development

(04/00706/FUL) located adjacent to the Tweed upstream of the confluence with the Gala Water. It appears from the information available that there is buffer zone between this development site and the Tweed and hence impacts on the SAC are considered unlikely.

Galashiels is a significant population centre and, given the age of the town, it is likely to be served by a mixture of surface water drains and a combined sewer system. It is anticipated that the daily impacts of a town the size of


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Galashiels, with a combined sewer system is to generate more sediment than the remaining developments proposed within the vicinity of Galashiels. Upper Catchment

Applications that lie in the topographic catchment boundary upstream of Galashiels are summarised in Table 6.4. Within the very rural upper catchment, the residual impacts of developments may be more significant. With appropriate mitigation measures in place, there is little justification for expecting these developments to have an adverse impact on the integrity of the SAC.

Table 6.4 Planning Applications within the Gala Water Upstream of Galashiels

Application Type Location 04/02420/FUL Wind farm Lies across two small

tributaries to the Gala Water.

04/01744/FUL. Wind farm Appears to lie predominately within a sub catchment of the Leader Water to the east.

04/00317/FUL Wind farm Approx. 50% of the site lies within the Halk Burn sub catchment and access is proposed form the A7.

02/00937/FUL Agricultural building (not located near to stream).

04/01516/FUL Agricultural building (not located near to stream).

04/01714/FUL

Housing development 25 houses away from water courses.

02/01947/FUL Housing development House conversion. 01/01499/OUT Housing development Located on the other side of

the railway line form the Gala Water but localised flooding possible.

03/01152/FUL

Housing development 10 houses near stream.

02/02075/FUL Agricultural building Located away from tributary to the Gala Water.

04/01245/FUL Agricultural building Cattery located within the village of Stow.

04/01245/FUL Private dwelling Construction of house within the village of Stow.

04/00351/FUL Housing development 28 houses located on the opposite side of the railway line to the Gala Water but potentially within the floodplain.


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6.7.4 Summary

Planning permissions have been approved for a number of other projects within the catchment which vary in size. It has been assumed that many of these projects have been constructed and therefore, that any impacts on the Gala Water and the SAC have been considered as part of the approval process and found to be acceptable. Two projects have required Appropriate Assessments as they were considered to have the potential to significantly affect the SAC. However, one of these has been approved, and the other at Boleside near Galashiels appears unlikely to proceed. A number of the applications are within the Galashiels area and are unlikely to result in significant impacts to the SAC. The other applications within the upper catchment are either small proposals, located away from the river , replacement of existing structures, or types of development that with appropriate mitigation are unlikely to result in significant impacts to the river. The assessment presented in Section 5 of this report concludes that, with the implementation of the mitigation set out in this document, the Waverley project on its own should not have significant impacts on the Gala Water and hence is unlikely to result in significant in=combination effects.


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7 MONITORING

7.1 OVERVIEW AND OBJECTIVES

The baseline habitat conditions of the Gala Water were established through the baseline surveys undertaken for the assessment. A monitoring strategy has been developed in order to: • confirm site specific baseline conditions prior to construction to ensure

that appropriate construction mitigation measures have been adopted and form part of the CoCP;

• ensure that the mitigation measures proposed in the CoCP will adequately

protect the key habitats and species during construction; • ensure that the mitigation measures proposed in this report, the

Environmental Statement and the CoCP will adequately protect key habitats and species against permanent change as a result of the presence of the new engineering structures; and

• identify any post construction changes to key habitats and species and the

likely causes. The monitoring measures proposed fall into four categories as follows: • pre-construction monitoring; • construction monitoring; • post-construction monitoring; and • long term post-construction monitoring. These are discussed in the following sections. The detailed scope of the monitoring will be agreed with SNH and/or SEPA prior to construction.

7.2 PRE-CONSTRUCTION MONITORING

7.2.1 Confirming the Presence of Qualifying Interests

The assessment of effects on the Gala Water has identified a number of locations where site specific mitigation measures are required as a result of a potential interaction between the presence of a key habitat or species (ie lamprey juvenile habitats, Annex I CB community species and otter shelters) and potential indirect impacts from proposed engineering works. Where there is the potential for such indirect impacts, pre-construction monitoring to reconfirm the presence of the habitats and species is proposed. The exact locations of the qualifying interests will be incorporated onto


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construction drawings and awareness training will be undertaken to ensure that all contractors are aware of the areas that need to be treated with care.

7.3 CONSTRUCTION MONITORING

7.3.1 Suspended Solids

It is noted that there is the potential for indirect impacts to the Annex 1 CB communities at some locations (downstream of construction works) as a result of increased suspended solids during construction. Mitigation measures have been proposed to ensure that the release of suspended solids is minimised; it is proposed that an appropriate specialist is present to install sediment fences and plant washing facilities sediment as appropriate. In order to monitor the effectiveness of the suspended solid mitigation measures, monitoring is proposed on a regular basis throughout the construction period. In doing this, it is important to take into consideration that there is a degree of natural variation in the catchment. High sediment levels may occur as a result of construction activities or may naturally occur as a result of flood events resulting in significant disruption to the river channel. It is proposed that SEPA’s suspended solids concentration data (collected at the Gala Foot) is analysed to both detect and attribute abnormal suspended solids concentrations. It is proposed that SEPA is consulted and an approach is adopted to ensure that any water quality issues are detected and addressed as they are detected.

7.4 POST-CONSTRUCTION MONITORING

7.4.1 Monitoring to Check the Effectiveness of Construction Mitigation

Post-construction monitoring is proposed to determine the effectiveness of the mitigation measures during construction. Upon completion of construction, the identified habitats will be assessed by an appropriate specialist to determine if any detrimental impacts have occurred during construction; the assessment will be made against the criteria used in the impact assessment. The findings of the surveys will be communicated to SNH.

7.4.2 Monitoring to Establish Medium Term Mitigation Measures

In addition to the above monitoring, and before the long term monitoring after two years, the extent of the stabilisation of the banks through re-vegetation will be assessed. Monitoring for evidence of erosion of the banks, ie identifying bare surfaces, will be undertaken and SNH and SEPA will be consulted on whether medium term mitigation is required until revegetation is completed. The medium term mitigation option will consider the protection of bare surfaces using appropriate geotextiles covers, the maintenance of


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sediment fencing and routine site visits to monitor the level of instream sedimentation resulting from the sustained erosion.

7.5 LONG TERM POST-CONSTRUCTION MONITORING

7.5.1 Comparison of the Qualifying Interests, Pre-and Post-Construction

It is proposed that repeat surveys for the qualifying interests are carried out two years after scheme completion, or at a time deemed appropriate in consultation with SNH. The scope and extent of these repeat surveys will be agreed with SNH. The results from these repeat surveys will be compared with the results from the original baseline surveys to assess whether the habitat potential for Annex II species is significantly different at the catchment scale and whether the diversity and abundance of the Annex I CB communities has been significantly altered. The findings will be reported to SNH. The CB communities and reaches of lamprey juvenile habitat are very susceptible to physical disturbance associated with extreme high flow events. Furthermore, extreme drought is also likely to result in adverse impact. It is important to determine whether any changes are attributable to the engineering works or extreme hydrological events. A direct comparison of the original baseline surveys and post construction surveys will only be possible if there have been no extreme hydrological events (eg high flow or drought) between the original baseline surveys and the proposed repeat construction surveys. Catchment hydrology will be analysed immediately prior to any proposed repeat surveys and water flow records from SEPA’s gauging station at Galashiels will be analysed by an appropriate specialist to evaluate the severity of any flood or drought events experienced within the catchment since the baseline surveys were undertaken. If one or a number of extreme events have been recorded within this period, (particularly towards the end of the period), then the repeat surveys may not differentiate between the long term consequences of the scheme and short term degradation of habitats associated with the extreme events and it may be appropriate to defer the surveys. Consultation is proposed with SNH accordingly.

7.5.2 Scour

Engineering surveys will be carried out at any river bank protection site where scour is evident as a result of the works. This will be undertaken routinely by Network Rail as part of their maintenance procedures. Any remedial work required will actioned by Network Rail in consultation with SNH.


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8. SUMMARY

The Gala Water is part of the River Tweed SAC, which is designated because of the international importance of its CB communities, otter, Atlantic salmon, and lamprey. These are known as the qualifying interests. The route of the Waverley Line affects the Gala Water in 49 locations along its length and the Competent Authority is required to undertake an Appropriate Assessment under the Habitats Regulations. This is to assess the effects of the proposed development on the integrity of the SAC by considering the impacts of the proposals on the qualifying interest against the conservation objectives for the site. The direct impacts on the Gala Water arise from river bank protection works, bridgeworks and scour protection where in-river diversions are required during construction, and a diversion of a stretch of the Gala Water. The main impacts are from the river bank protection and river diversion as the footprints of the majority of the bridge structures will be similar to that which exists. Few plants from the important CB communities will be directly affected and mitigation will be implemented to help protect the more important areas adjacent to the proposed development sites, thus not adversely affecting the communities. The proposals will not have significant effects on the spawning or juvenile habitat of salmon or lamprey, nor will the works result in a barrier to their migration. Mitigation measures will be implemented to control sediment dispersal. Disturbance to otters will occur in five locations, from the loss of one holt and four couches (resting places) and a licence will be required from The Scottish Executive to undertake work in these areas. Subject to this licence, the loss of the holt will be mitigated by the installation of two artificial holts in suitable locations which will not be subject to disturbance from the operating railway. Measures will also be taken to reduce the risk of pollution, maintain the paths of otters whilst foraging and to reduce the risks of animals crossing the tracks once the trains are operating. Once operational the railway will have no direct impact on the river and mitigation measures will be implemented to reduce the risk of pollution from run-off, spillages etc. The river bank protection work is largely to replace or repair existing structures. The current design will incorporate measures to reduce the risk of erosion to the river banks down stream. These will be refined further during the detailed design stages in agreement with SNH. The Waverley project is not predicted to have significant in-combination effects with other developments in the vicinity of the Gala Water.

waverley railway (scotland) · 2011. 12. 20. · environmental resources management waverley...

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