A816 Ardfern Permanent Repair Solution Update
Argyll and Bute Council · 11 September 2025
Back to Environment, Development and Infrastructure Committee — 11 September 2025 and its agenda
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ARGYLL AND BUTE COUNCIL ENVIRONMENT, DEVELOPMENT AND INFRASTRUCTURE COMMITTEE ROADS AND INFRASTRUCTURE 11 SEPTEMBER 2025 A816 ARDFERN PERMANENT REPAIR SOLUTION UPDATE 1.0 EXECUTIVE SUMMARY 1.1 This report provides an update on progress towards a permanent repair of the A816 at Ardfern which was damaged during the severe weather event in October 2023. RECOMMENDATIONS It is recommended that Members of the Environment, Development and Infrastructure Committee:- a) Agree that the existing budget allocation of £1.1m be used to progress the next phase of detailed business case development required to provide a recommended option with a further and more highly developed budget estimate and outline delivery programme. b) Note the difference in the current cost estimate and that originally produced and reported to Members in February 2024 and the reasons for this set out in the body of the report.
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ARGYLL AND BUTE COUNCIL ENVIRONMENT, DEVELOPMENT AND INFRASTRUCTURE COMMITTEE ROADS AND INFRASTRUCTURE 11 SEPTEMBER 2025 A816 ARDFERN PERMANENT REPAIR SOLUTION UPDATE 2.0 INTRODUCTION 2.1 This report provides an update on progress towards a permanent repair of the A816 at Ardfern which was damaged during the severe weather event in October 2023. 2.2 This report sets out the findings of an options assessment commissioned by the Council and undertaken by specialist consultants. The options assessment provides a number of potential options for a re-constructed road which have been further reviewed by Council officers to create a shortlist of preferred options that it is now proposed are subjected to further more detailed review in order to arrive at a single option which can be recommended to be taken forward. 3.0 RECOMMENDATIONS 3.1 It is recommended that Members of the Environment, Development and Infrastructure Committee:- a) Agree that the existing budget allocation of £1.1m be used to progress the next phase of detailed business case development required to provide a recommended option with a further and more highly developed budget estimate and outline delivery programme. b) Note the difference in the current cost estimate and that originally produced and reported to Members in February 2024 and the reasons for this set out in the body of the report. 4.0 DETAIL 4.1 The A816 through Bealach Mor is a main ‘A’ class road and is the main connection route between Oban and Lochgilphead. The road runs along the northern slope of Creag nam Fitheach (214m), A’ Bheinn (246m).
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4.2 On the 7th October 2023 as a result of exceptional rainfall, the wettest 2-days in series from 1891, with 100-150mm rain falling widely across Southern and Central Highlands (Kendon, 2023). Approximately a month of rainfall fell in a 36- hour period in a number of areas within Argyll and Bute. 4.3 The heavy rainfall fell onto already saturated ground and triggered 3no. separate but closely spaced debris flow events (wet saturated landslides that flow) from the steep slope immediately adjacent to the A816. This deposited approximately 6000 tonnes of material over nearly 200m length of road, with more debris on the surrounding slopes and fields. 4.4 Clearance works removed an estimated 10,000 tonnes of debris, from the original event and subsequent debris from later smaller events and erosion / wash out of material remaining on the slope. 4.5 Owing to the ongoing movement and potential for further blocks and/or debris to impact the road a temporary bypass route was constructed as the fastest and safest way to reopen the A816. The bypass opened to the public on the 16th December 2023, following 6 weeks of construction (Figure 1). Due to landowner, environmental, engineering and archaeological challenges and constraints the temporary road is built in a restricted narrow corridor resulting in a single lane with passing places, open ditches with steep side drops, a sharp corner and very steep incline at the western side. Built as a temporary road, i.e., not to highway standard, the road is approximately 320m length and the alignment was chosen to follow existing track and foundation of the military road to minimise foundation and subsidence issues. The road is constructed to Forestry Land Scotland specification (as a floating road), as far as practicable, with a covering of asphalt. 4.6 Following the completion of clearance works, construction of protective barrier systems and the implementation of a temporary traffic light system to control single lane running traffic was returned to the original route of the A816 and the temporary diversion road closed on 13th September 2024.
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4.7 In order to investigate the options available for a permanent road re-instatement the Council commissioned a consultant to undertake an options assessment and report. The study examined numerous potential route options with nine options were taken forward for assessment. These range from a do minimum approach, utilising the existing A816 and bypass through to a complete realignment of the road. 4.8 The consultants have used cost data from recent upgrades of trunk road schemes in similar environments to produce initial cost estimates. It is only possible at this stage without detailed route ground investigation and design to provide outline costings and these are likely to be subject to change as further design development takes place. It is noted that the A816 may not be constructed to the same standard as the projects used for cost comparison but at the current point in time utilizing cost data from recently completed trunk road schemes is believed to provide the best available comparison. 4.9 Prior to the Options Assessment to which this report relates an initial and very early cost estimating exercise was undertaken in early 2024 in order to provide a broad order of cost magnitude. This exercise suggested a cost of £1.1m and this was identified as a requirement for the project in the Council Budget Pack in February 2024 where on page 166 at 3.5.6 it was stated “As a result of a significant weather event on 7 October 2023, Argyll and Bute Council activated the Bellwin scheme in relation to the recovery costs associated with the incident. The funding from this scheme is welcomed however eligibility criteria of costs are restrictive. Capital expenditure does not qualify therefore any long term replacements to infrastructure such as bridges cannot be claimed through the scheme. Works to the value of £3.248m have been identified in the short term with future long term works costing circa £1.1m being identified, both will require capital funding.” Without the benefit of a full options study this provisional estimate was based on widening the temporary bypass road from circa 3m to 6m (to allow two-way traffic) along an approximately 320m length. At this earlier stage an indicative cost of £1,500/m plus additional costs for consents, licenses, ground investigations, design fees, plus a contingency allowance of 20% to produce a high-level estimated cost of £1.1m. 4.10 In the course of developing the options report the external consultants identified two further significant geotechnical issues that will need to be addressed as part of the works to construct a permanent repair to the A816. These additional issues, which were not known at the time of the initial budget estimated in February 2024, and consist of: • The risk of failure of steep ground on the lower embankment of the A816 just to the north of the area immediately impacted by the landslip in October 2023. The cost of repairing this is estimated at up to £2m. • A large tension crack (around 25m in length) on the slope above the A816 where the existing bypass meets the A816 i.e. just to the south of the area directly impacted by the landslip in October 2023. This is a surface expression of a larger instability, thought to be a larger slip feature affecting the carriageway
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which will need to be remediated to prevent ongoing damage to the road foundation and surface. The cost of repairing this issue is estimated at up to £1.5m. 4.11 The options put forward within the consultants report have been reviewed by officers and a shortlist of options for further consideration has been produced. These options and a summary of the rationale is set out in Table 1 below (numbering and naming are as per the consultants report at Appendix 1): Table 1 - Options for Further Consideration: Option Description Estimated Cost – Option plus Additional Described at 2.9 Status and Rationale Option 3: Pink Route Move the A816 approximately 5- 10m to the north and construct a large pit/bund structure (potentially with additional rock fall barriers on top) to protect the road. Length: Approx. 525 m £7m - £8.75m Not preferred at this stage due to ongoing maintenance liabilities. Option 4: Yellow Route Widening and upgrade of the existing temporary bypass route with removal of the £7.25m - £8.5m Preferred at this stage due to relocating road away from residual hazard.
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sharp, steep corner and realignment of the joining to the A816. Length: Approx. 460 m Option 5: Blue Route Widening and upgrade of the existing temporary bypass route with removal of the sharp, steep corner by realigning the eastern side of the bypass to the south. Length: Approx. 405m £6.5m - £7.5m Not preferred due to risk from future landslips, archaeological risks and poor road alignment.
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Option 6: Green Route Widening and upgrade of the existing temporary bypass route for the eastern section of the route. A new western section would be constructed from the corner of the A816 north of the bypass Length: Approx. 580m (approximately 190m of new road construction) £8.5m - £10m Not preferred due to high cost.
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4.12 Due to the level of investment estimated to be required it is important that the shortlisted options are subjected to further review and business case development in line with the Councils Project Pipeline approach. With a large number of significant infrastructure projects currently either in design or delivery the Council does not have available the personnel with the correct experience and knowledge to do this. Therefore it will be necessary to procure the services of a specialist consultancy to take forward the business case development initially to Strategic Outline Business Case and preferred option stage and then subsequently, subject to further Member approvals and budget allocation to Outline Business Case and Final Business Case. Consultants will be procured such that they can be retained for the full project life-cycle from the current point through to final completion to augment the capacity of Council staff to manage this project. 5.0 CONCLUSION 5.1 This report recommends next steps in relation to the delivery of a permanent repair to the section of the A816 at Ardfern damaged during the October 2023 severe weather event. 6.0 IMPLICATIONS 6.1 Policy – None identified. 6.2 Financial - The estimated costs of this project are outlined in the body of the report. It is estimated that the current capital allocation of £1.1m will be insufficient to enable completion of this project. The current budget of £1.1m is estimated to be sufficient for the next phase of project development included in the recommendations. 6.3 Legal - There will be a range of legal matters related to this project including land ownership and contractual matters. 6.4 HR – None identified.
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6.5 Customer Service – None identified at this time. 6.6 Risk - A range of risks are related to this project in terms of affordability, timescale, land related and issues related to regulatory approvals. There is a risk of further landslips at this location due to the topography and geology – this is an important consideration in finalizing the preferred route option in order to mitigate as far as reasonably practicable future risks to the travelling public and future risks to transport connectivity. 6.7 Climate Change - By removing the need for traffic lights at this location this project should lead to minor lowering of transport related CO2 outputs through removing vehicle idling. The construction of the project will however represent embodied CO2 as do all construction projects. 6.8 Fairer Scotland Duty – None identified at this time. 6.9 Equalities - protected characteristics – None identified at this time. 6.10 Consumer Duty – None identified at this time. 6.11 Island Communities - The A816 is an important transport corridor that links points of connection to the islands by ferry services. 6.12 Children’s Rights and Wellbeing – None arising directly from this report. Kirsty Flanagan, Executive Director with responsibility for Roads and Infrastructure Councillor John Armour, Policy Lead for Roads, Transport and Amenity Services September 2025 For further information contact: Andy Summers, Head of Roads and Infrastructure Service Andrew.Summers@argyll-bute.gov.uk Elsa Simoes, Infrastructure Design Manager Elsa.simoes@argyll-bute.gov.uk Hugh O’Neill, Network and Standards Manager Hugh.oneill@argyll-bute.gov.uk APPENDICES Appendix 1 – Options Assessment Report A816