Oban Flooding Update
Argyll and Bute Council · 20 June 2024
Back to Environment, Development and Infrastructure Committee — 20 June 2024 and its agenda
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ARGYLL AND BUTE COUNCIL ENVIRONMENT, DEVELOPMENT AND INFRASTRUCTURE COMMITTEE ROADS AND INFRASTRUCTURE 20 JUNE 2024 SERVICES OBAN FLOODING UPDATE 1.0 INTRODUCTION 1.1 Historically there have been numerous flooding events within the Oban. The sources of the flooding consists of water from; coastal, fluvial (water course), surface water and combined sewer overflows. In some cases the combined effects of some of these flooding sources has increased severity of the flood hazard in Oban. One localised flood hotspot affected by combined source flooding is centred on the Council’s Lochavullin Road Car Park bounded by Soroba Road, Tesco and Lochavullin Road. 1.2 Preventing future flooding will require significant works which currently are unfunded. Through this report it is proposed that all funding opportunities are explored including lobbying Scottish Government to seek to secure funding to implement flood prevention works as well as exploring any additional external funding opportunities. 1.3 A number of short, medium and long term actions and works identified to help to mitigate flooding are detailed in this report. 2.0 RECOMMENDATIONS 2.1 It is recommended that the Environment, Development and Infrastructure Committee: i. Consider and note this report. ii. Endorse the proposals by officers to lobby for funding and to explore external funding opportunities 3.0 DETAIL 3.1 SEPA’s Flood maps (Appendices 1,2 and 3) show areas susceptible to Coastal, Fluvial (watercourse) and Surface Water flooding. Full map coverage available from Flood Maps | SEPA - Flood Maps | SEPA 3.2 Coastal flooding is influenced by high astronomical tides and tidal surges caused by low atmospheric pressure and storm events. In certain conditions, when high spring tides are worsened by tidal surge, sea water will flood into the tidal reach
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of the Black Lynn burn. The combination of tidal and high flows in the Black Lynn burn cause flooding in adjacent areas. Subject to the necessary permissions it is proposed that some clearance work is carried out. Whilst these works will provide some additional water storage capacity, they are not expected to mitigate against any significant weather event. 3.3 In addition to this the Scottish Water combined sewers (drains that contain both storm water and foul sewerage) can also surcharge adding raw sewerage to the combined source flood waters. The Lochavullin car park has a pumping system which copes with low levels of water, however, above a certain level there is nowhere to pump water to and the pumps become ineffective. 3.4 The consequences of these flooding events can often result in roads having to be closed for safety resulting in significant diversions and significant flood damage to adjacent businesses. 3.5 Climate change is very likely to increase the severity and frequency of flood events. Current guidance (SEPA Climate change allowances for flood risk assessment in land use planning) points to the following changes: • By 2100 Peak River Flows in Argyll increase by 59% of the 2017 values • By 2080 Peak Rainfall Intensities increase by 46% of the 2017 values • By 2100 cumulative rise in sea level above 2017 levels will be 0.86m 3.6 In Cycle 1 of the Highland and Argyll Local Flood Risk Management Plan 2016- 22 Oban was identified as a Potentially Vulnerable Area (PVA) for flooding and an Action was placed on the Council to carry out a Flood Study and Surface Water Management Plan. 3.7 A detailed Flood Study and Surface Water Management Plan (SWMP) was completed in 2019. The Oban Flood Study and SWMP has identified a number of mitigation and adaptation measures. These measures will require significant infrastructure and are likely to require attenuation (creating storage capacity for water either via a reservoir(s) or in underground tanks) for storm water as well as creating sea defences to prevent flooding from tidal surge. At present detailed design has not been progressed however it is reasonable to assume that works to deal with the flooding issues would run to several millions of pounds. In the recent past, the Council has been successful in securing funding for flood studies and physical works such as those underway in Campbeltown. These studies and physical works have been 80% funded by Scottish Government and 20% by the Council. At the time of writing, the next round of flood funds has not been released and it is currently unknown as to what, if any, funding will be available and over what period of time. 3.8 On 7-9 October 2023, the flooding in Oban was significant. Connectivity including access to hospitals and healthcare, residential property, light industry, commercial and retail premises were all affected. Access to shops and food stores was cut off and general disruption including flooding of the underground fuel tanks at Tesco superstore which resulted in no fuel being available from this site for a
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number of weeks. In addition there were a number of commercial properties, some Council owned that were affected on the Lochavullin site. Future Actions 3.9 Short term actions during a flood event:- The Council will continue to respond as required assisting emergency services and others where possible to do so. In addition to ensuring the pumping system for Lochavullin car park is functioning, the Council’s input during a flood event is likely to include providing the necessary signage, posting service disruption notices via the website and working closely with Partners through the Local Resilience Partnership and responding and assisting where possible. An Oban Local Flood Resilience Group has been established by volunteers with an initial meeting held with Council officers. This local community group is a good point of contact and it is understood that they are linked in with the Scottish Flood Resilience Forum. Officers will work collaboratively with this group. 3.10 Medium term actions include:- • Watercourse inspection of Black Lynn Burn and its tributaries; • Clearance of obstructions (trees, trolleys etc) noted during inspection; • Topographic and Bathymetric surveys carried out for the area immediately surrounding Black Lynn Burn (this shall be commissioned to a specialist consultant); • Hydrologic study to be carried out for the Black Lynn Burn (this is being commissioned to a specialist consultant); • Repair the existing pumping system at Lochavullin car park: o Existing control unit repaired / replaced as required and raised on a plinth to reduce risk of future water damage; o Existing pumps replaced as required; o Investigate whether existing pump outfall can be moved downstream • Consult with SEPA on consents for watercourse clearance and repair works following watercourse inspection (it has since been noted that Japanese Knotweed is present along the Black Lynn Burn, which will need to be considered, including any Japanese Knotweed upstream); • Secure quotes for proposed works to identify if funding can be identified within available budgets or otherwise secured; • Further collaboration with Scottish Water regarding sewer flooding and identify options to share resources and reduce this source of flooding; • Make representations to Scottish Government seeking to make available funding to accelerate flood prevention works at Oban; • Explore all opportunities for securing any available funding to accelerate flood prevention works at Oban. 3.11 Long term actions include:- • Long term works will be significant and likely to run into tens of millions of pounds requiring attenuation/water storage and general climate
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change adaptation measures aimed at mitigating or minimising disruption from severe weather events; • Currently SEPA prioritise residential property above businesses in terms of assessment and allocation of funding. The Council will lobby to seek to secure funding to accelerate flood prevention works at Oban; • No identified funding for major works; • Currently SEPA have a public consultation underway regarding Oban Potential Vulnerable Area (PVAs) which runs until 24 June. This consultation is covered on another agenda item for this meeting; • The impact of revised PVAs on future LFRMP Actions is uncertain at present, as information becomes available further updates will be brought forward to Members; • NOTE – PVAs highlight the potential risk of flooding, this will enable any development to take flooding into consideration and ‘build in’ flood mitigation by raising levels, adding in flood defence etc. PVAs also help in seeking external funding to mitigate against flooding. Impact on Local Businesses and Council Tenants 3.12 Some of the properties in Oban which have been affected by the recent flooding are owned by the Council and are leased to commercial tenants. These properties are located within the Lochavullin area where the Council leases premises in Mill Lane, Millpark Road and Crannog Lane. Some of the properties have been affected by flooding before but the tenants have reported that the recent flooding events have been worse than previously experienced. 3.13 A number of tenants have contacted the Council to seek compensation or rent reductions to reflect the impact of the flooding on their businesses. However, there are also businesses in the same area who either own or privately lease their premises and it would not be fair if compensation or rent reductions were only offered to Council tenants. Accordingly it is considered that only a centralised support scheme made available through the Scottish Government would offer an equitable response to the impact of the recent flooding events. 3.14 As part of the wider flood prevention works being investigated and undertaken by the Council, additional survey work of the drainage systems around the Lochavullin area has been instructed by the Estates Section. This is to assess if there are any short term measures which could be taken to make improvements to address specific issues some tenants are having. The drainage systems have been altered over the years by a number of tenants and understanding how this impacts on the wider network will assist to determine if any short term measures will improve matters. There may also be a role in this exercise for Scottish Water depending on the outcome of the surveys and it should be noted that these works will not address the larger scale flooding events which require a larger flood prevention scheme as outlined elsewhere within the report. Other Affected Locations 3.15 There are a number of sites already included within a list of potential flood
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prevention schemes that may receive funding from future Scottish Government allocations. There are also additional sites that have been prone to recent flooding that are not included in Scottish Government’s list of schemes, these include Ledaig car park at Tobermory and Kilmichael Glen. Both of these locations have been subject to recent flooding. 4.0 CONCLUSION 4.1 This report provides the Environment, Development and Infrastructure Committee with an update on flooding in Oban and potential medium and long term adaptation options. This report also acknowledges other sites across Argyll and Bute which do not currently feature on any flood plans. The report also proposes to seek external funding with the intention of bringing flood prevention works forward whilst also recognising that the works required to mitigate flooding in Oban will be significant. 5.0 IMPLICATIONS 5.1 Policy – In line with existing Council policies and in line with the Flood Risk Management (Scotland) Act 2009. 5.2 Financial – No funding identified for long term solution, this report proposes that lobbying is taken forward with a view to securing funding. 5.3 Legal – The Council has four key responsibilities under the Flood Risk Management (Scotland) Act 2009: • Prepare maps of bodies of water etc • Assess bodies of water • Prepare local flood risk management plans and carry out the Actions identified in the LFRMP • Carry out clearance and repair works. 5.4 HR – None known. 5.5 Fairer Scotland Duty: None known. 5.5.1 Equalities - protected characteristics – An EqSEIA will be required as and when long term solutions can be progressed. 5.5.2 Socio-economic Duty – None known. 5.5.3 Islands – None known. 5.6 Climate Change – Due regard will be given to climate change with a view to minimising any climate change impact and these will be considered as and when they arise. 5.7 Risk – None known. 5.8 Customer Service – None known.
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5.9 The Rights of the Child (UNCRC) – None known. Executive Director with responsibility for Roads and Infrastructure Services: Kirsty Flanagan Policy Lead for Roads, Transport and Amenity Services: Councillor John Armour May 2024 For further information contact: Jim Smith, Head of Roads and Infrastructure Services jim.smith@argyll-bute.gov.uk Elsa Simoes, Infrastructure Design Manager elsa.simoes@argyll-bute.gov.uk APPENDICES Appendix 1 - Plan shows the SEPA River flood hazard. Appendix 2 - Plan shows the SEPA Coastal flood hazard Appendix 3 - Plan shows the SEPA Surface Water flood hazard
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Appendix 1 - Plan shows the SEPA river flood map - Search Location - Tesco PA34 4HP 0.1% = 1 in 1000 year chance of flooding 0.5% = 1 in 200 year chance of flooding 1% = 1 in 10 year chance of flooding
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Appendix 2 - Plan shows the SEPA coastal flood map Search Location – Tesco PA34 4HP 0.1% = 1 in 1000 year chance of flooding 0.5% = 1 in 200 year chance of flooding 1% = 1 in 10 year chance of flooding
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Appendix 3 - Plan shows the SEPA coastal flood map Search Location – Tesco PA34 4HP 0.1% = 1 in 1000 year chance of flooding 0.5% = 1 in 200 year chance of flooding 1% = 1 in 10 year chance of flooding