North Uist (Potentially Vulnerable Area 02/05)

North Uist (Potentially Vulnerable Area 02/05) Local Plan District Local Authority Main Catchment 02 Outer Hebrides Comhairle nan Eilean Siar North Uist Coastal Background This Potentially Vulnerable Area (PVA) is By contrast the north-west of the PVA located on North Uist and comprises the comprises of mainly higher ground. majority of the coastline from Loch nan Geireann in the west to Loch Nam The A865 follows the eastern coastline Madadh in the east. The PVA covers an of North Uist to Lochmaddy and then area of approximately 162 km² (Figure 1). runs west and south to the causeway at North Fords. There are a significant number of lochs located in the low lying south-east of the The total Annual Average Damages PVA. (AAD) for all flood sources is £19,000. The majority of the damages are from coastal flooding (87%), with river flooding contributing 13% of the damages (Figure 2). Figure 2: Annual Average Damages by Flood Source Figure 1: North Uist Potentially Vulnerable Area This area was designated as a PVA due to flood risk to transport links, agricultural land, sites of cultural heritage and environmentally designated sites based on information available at the time of the National Flood Risk Assessment in 2009. Designation as a PVA means that further investigation of that flood risk was required. This has been carried out based on the flood hazard and risk maps published by SEPA in January 2014 together with input from the Local Plan District Partnership. Summary of Impacts from all sources of flooding Flooding to roads contributes 40% of the damages to the total Average Annual Damages with damages from flooding to agricultural land and residential properties contributing 29% and 25% respectively. The residential properties are at risk from coastal flooding although the total number of properties at risk is relatively small. The areas of agricultural land and designated areas at risk are similar for river flooding and coastal flooding. The most notable areas at risk from flooding are on the A865 at Clachan which cuts off the only route to the local Primary School causing disruption to the community. Additionally on the A865 at Committee Road North the road is at risk from flooding during less frequent events. Several of the causeways linking the islands are known to be vulnerable to flooding, for instance the Baleshare and North Uist causeway particularly at Grimsay. Areas of environmentally designated sites are identified as at risk. The sites affected include North Uist Machair, which is a Special Area of Conservation (SAC), North Uist Machair SAC, Obain Loch Euphoirt SAC, Loch Nam Madadh SAC, Mointeach Scadabhaigh Special Protection Area and SAC) and Loch Obisary Site of Special Scientific Interest (SSSI). There are 13 cultural heritage sites at medium to high risk of flooding all of which are designated as Scheduled Ancient Monuments. The sites are all prehistoric domestic, defensive, or ritual and funerary sites and include the Caisteal Odair promontory fort and the Sornach Coir’Fhinn stone circle. Cultural heritage sites do not contribute to the AAD total as it is difficult to quantify a monetary value for them. Table 1 presents a summary of the receptors at risk from all sources of flooding in the different return periods (different probabilities of flooding in any one year). The contribution from the different receptors to the overall damages (by return period) is shown in Figure 3. Figure 4 shows the location of receptors that are at medium to high risk of flooding from all sources in the PVA. Table 1: Summary of Flood Risk from all sources High Risk Medium Risk Low Risk 1 in 10 year 1 in 200 year 1 in 1000 year Number of Residential 3 3 5 Properties at risk (out of 455) Number of Non-residential 0 0 0 Properties at risk (out of 151) Number of People at risk 7 7 11 Community Facilities at risk 0 0 0 Utilities at risk 0 0 0 Transport Links at risk Roads (33 locations) Roads (47 locations) Roads (48 locations) Designated Areas (km 2) at 4 km 2 5 km 2 5 km 2 risk Number of Cultural Heritage 11 13 15 Sites at risk Agricultural Land at risk 3 km 2 4 km 2 4 km 2 (km 2) Figure 3: Damages by receptor and return period for flood risk from all sources Figure 4: Location of receptors at medium to high risk of flooding from all sources in the North Uist PVA Summary of existing local actions to manage flood risk There are no known formal flood defences within the PVA. Comhairle nan Eilean Siar takes flood risk into consideration as part of decisions related to land use planning, as outlined in Scottish Planning Policy. This includes ensuring that new developments are not permitted in areas at risk of flooding and that all new developments do not increase flood risk elsewhere. Floodline, SEPA’s flood warning service, provides flood alerts for the Outer Hebrides. Summary of Objectives to manage flood risk in PVA Local Plan District Initial Objective Indicator Avoid an increasing the number of residential and From an estimate of 224 non-residential properties at risk from all sources of residential properties flooding. From an estimate of 152 non- residential properties North Uist (PVA 02/05) Initial Objective Indicator Reduce disruption to transport at high risk from 17 road locations at high risk coastal flooding Initial objectives for cultural heritage and environmental designated sites may be added when information is available from the relevant body at the end of the objectives sections. Summary of Measures to achieve Objectives <<to be completed following Work Package 3>> .

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