Corran Narrows
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Table of Contents 1.0 Executive Summary 5 Overview 5 Why commission this study now? 5 What is the scope of this study? 5 What can be learned from previous Scottish fixed links? 6 What are the key environmental, planning and construction considerations at Corran? 6 What route corridors and alignments have been considered? 7 Fixed Link Structure Options 9 What are the potential scale of benefits of a fixed link? 11 How might a fixed link impact on the economy and society of the area? 13 What are the key conclusions? 16 What are the next steps? 16 Corran 2.0 Introduction 19 2.1 Overview 19 Narrows: 2.2 Why Commission This Study Now? 19 2.3 Study Scope 20 2.4 Corran Ferry Stag Appraisal 20 Fixed Link Outline 2.5 Report Structure 20 Feasibility Study 3.0 Case Studies 23 3.1 Overview 23 3.2 The Case For Fixed Links 23 3.3 Recent Experience, Standards And Procurement 24 Prepared for The Highland Council, HITRANS 3.4 Case Studies – Outcomes & Impacts Of Fixed Links 29 & HIE Prepared by Stantec 4.0 Planning & Environmental Context 38 4.1 Overview 38 Date: March, 2020 4.2 Study Area 39 4.3 Environmental Considerations 40 4.4 Planning Considerations 43 4.5 Conclusion 45 5.0 Option Generation And Development 47 5.1 Overview 47 5.2 Key Characteristics Of The Corran Narrows 47 5.3 Route Corridor Identification 48 5.4 Route Corridors - Broad Alignments 55 5.5 Fixed Link Structural Options 59 5.6 Road Connections 77 6.0 High Level Economic Appraisal of a Fixed Link 83 6.1 Transport Economic Efficiency 83 6.2 Potential Wider Benefits of a Fixed Link 92 7.0 Conclusions And Next Steps 103 7.1 Conclusions 103 7.2 Next Steps 103 7.3 Recommended Next Steps 105 A. Model Assumptions 107 B. Model Parametres 108 2 Corran Narrows, Corran, Lochaber 1.0 Executive Summary Overview option, there is an affordability question, particularly within the context of limited local authority budgets. Recognising The Corran Narrows marks the dividing line between the upper this, the funding partners are seeking to potentially submit and lower section of Loch Linnhe, a circa 30-mile long sea loch the case for a fixed link into the ongoing STPR2, thus which runs along the Great Glen Fault. The loch separates progressing it into the national context. Nether Lochaber from Ardgour and the areas beyond, albeit it is possible to drive around the loch (with some restrictions for larger vehicles). As the name suggests, Loch Linnhe is at its What is the scope of this study? narrowest at Corran, circa 300 metres wide at its narrowest As alluded to above, this piece of work is a high-level feasibility point. study. The outcomes emerging from it will require further development, either within the context of STPR2 or as part of a The Corran Ferry service operates the short passenger and standalone business case comparing ferry and fixed link vehicle crossing of the Corran Narrows between Nether options. In terms of outcomes, this study: Lochaber and Ardgour. The service provides a lifeline connection linking the communities of Ardgour, Sunart, ‣ reviews case-study evidence on the cost, procurement and Ardnamurchan, Moidart, Morar, Morvern and, to a lesser socio-economic impact of equivalent fixed links; degree, the Isle of Mull to Lochaber. The ferry serves a wide variety of purposes including: providing access to employment ‣ identifies potential route corridors for a fixed link, within and other key services for residents; acting as a gateway for which alignments are developed; tourists visiting the peninsula; and meeting the supply-chain needs of the above communities. It is understood to be the ‣ considers the options in relation to the structural form of any busiest single-vessel ferry crossing in Europe. fixed link; Whilst the ferry has served communities on both sides of the ‣ provides a commentary on the required supporting road crossing for many years, there is a longstanding aspiration infrastructure and tie-ins to the existing network on both amongst peninsular communities for a fixed link across the sides of the crossing; Corran Narrows. Recognising the aspirations of these communities, a partnership of The Highland Council (THC), ‣ provides high-level capital and maintenance cost-banded Highlands and Islands Transport Partnership (HITRANS) and estimates for each fixed link option; Highlands and Islands Enterprise (HIE) commissioned Stantec to develop a high-level feasibility study for a fixed link across ‣ identifies the scale of potential Transport Economic the Corran Narrows. Efficiency (TEE) benefits of a generic fixed link, providing a quantified estimate of benefit ranges; Why commission this study ‣ compares the whole life costs of a fixed link with a now? continuing ferry service; and Whilst the desire for a fixed link at Corran has been a long-held aspiration, two factors have combined to create increased ‣ qualitatively explores the potential societal and economic urgency and need for this study: impacts of a fixed on both sides of the crossing. ‣ The future of the ferry service: Significant investment in new At this stage, the study does not: vessels, infrastructure and human resource is required in the near future, prompting the question as to whether a ferry or ‣ firmly define a preferred option in terms of alignment or fixed a fixed link represents the best long-term value for money link structural form; when considered in the widest sense (i.e. social and economic in addition to financial outcomes). ‣ recommend whether a ferry or fixed link is the most appropriate long-term option for the Corran crossing; or ‣ Strategic Transport Projects Review 2 (STPR2): STPR2 is a Transport Scotland-led study which will inform transport ‣ engage with communities and stakeholders. investment in Scotland for the next 20 years, ensuring that such investment is in line with the vision, priorities and The study findings help to determine whether there is merit in outcomes of the National Transport Strategy 2 (NTS2). considering fixed link options for the Corran Narrows further, Whilst this study may identify a fixed link as a feasible either within the context of STPR2 or more generally. 4 5 What can be learned from What are the key ‣ The Corran Narrows has tidal characteristics which impact What route corridors and on the air draught requirement of vessels. There are also previous Scottish fixed links? environmental, planning and aspirations to develop tidal energy schemes at Corran and alignments have been Case study evidence from fixed links constructed in the construction considerations at thus any fixed link should not prevent the future realisation considered? Highlands & Islands between the late 1970s and early 2000s of these projects. Five route corridors within which a fixed link could be located has been considered and the following broad conclusions can Corran? have been identified, comprising of four bridge corridor options be drawn: ‣ The requirement to maintain an appropriate air draught for and one tunnel corridor option. These are shown in the figure the transit of vessels along Loch Linnhe, accounting for the Environmental considerations below: ‣ It is reasonable to conclude that a Corran Narrows fixed link tidal range at the Corran Narrows, will be an important will lead to significant traffic generation. This is likely to be consideration. These route corridors can be broadly categorised as follows: due to a combination of: (i) latent demand for journeys which ‣ The following environmental issues would need to be are currently suppressed by the limitations associated with considered further at detailed design stage: ‣ The ferry currently provides the main dangerous goods route ‣ RC1 would be broadly on the alignment of the current ferry the ferry service - this would include peninsular residents onto the peninsula (and currently Mull), including for the service making more frequent trips to Fort William and elsewhere to ‣ the high likelihood of coastal flooding, especially on the transport of e.g. fuel and heating oil, agricultural products access services; (ii) increased visitor numbers, particularly in eastern bank of Loch Linnhe between Nether Lochaber and etc. which is an important aspect in the context of Corran ‣ RC2-RC4 would be to the north or south of the existing ferry terms of ‘unplanned’ or spontaneous trips; and (iii) additional Inchree, which can influence design and construction of any and the subsequent identification of potential fixed link service journeys generated by 24-hour connectivity. fixed link. options (i.e. transport of dangerous / hazardous goods through a tunnel) ‣ RC5 would be potentially suitable for a tunnel option.. ‣ The evidence suggests that the provision of a fixed link ‣ statutory ecological designations, particularly, the Onich to across the Corran Narrows would make a positive Ballachulish Woods and Shore Special Area of Conservation contribution to population retention and growth, although and the Site of Special Scientific Interest south-west of any effects would be long-term in nature and difficult to Inchree; and attribute directly to the crossing given that many factors impact on population numbers and structure. ‣ landscape designations and heritage assets, particularly, the Ardgour Special Landscape Area along the west side of Loch ‣ A fixed link across the Corran Narrows would provide Linnhe. residents of the peninsula with improved access to employment (and vice versa, although the effect in the other ‣ The above considerations will contribute towards informing NORTHERN direction is likely to be weaker). There is a risk that it creates the potential alignments for a fixed link. CROSSING (RC2) a ‘dormitory’ effect with an increase in commuting to Fort William or elsewhere, but this would nonetheless bring a ‣ It is though important to note that no ‘showstopper’ issues range of benefits to the peninsula in terms of increased local have been identified here from an environmental perspective spending power and the potential in-migration of working- which would preclude the construction of a fixed link across age families.