Potentially Vulnerable Area Datasheet. Potentially Vulnerable Area Datasheet. Catchment: Catchment: Catchment: data PVA PVA PVA: Hydrology Hydrology

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1 Potentially Vulnerable Area Datasheet Potentially Vulnerable Area Datasheet : Local Plan District: : : 05/01 Local Local Plan Plan District: District: 5 Fdhorn, Nairn and Speyside 5 5 Fdhorn, Fdhorn, Nairn Nairn and and Speyside Speyside Local Authority: Local Local Authority: Authority: o by t c FR urr e M n 22 S t d D tra ata ec te : em gie su be s p pe r 2 ub rse 01 lis de 5 he d d 05/01 05/01 Ma : Ma Ma : : Summary MaImpacts Impacts Summary Ma Ma Impacts Assessment past events shows previous reports Assessment reports Assessmentpast pastevents eventsshows showsprevious previous reports floodg impactg properties and transport lks floodg transport lks floodg impactg impactgproperties propertiesand and transport lks area. area. 260, ,000 Estimated Weighted Weighted Annual Annual 260,000 Weighted Annual 260, , ,000 Average Damages Damages Damages Known g g Known Source Source g 25% 25% 75% 75% Surface Water Water Surface Water Surface Surface Water Very High High Very LowLow High Groundwater Groundwater g g Impact Impact Climate Climate Change Change Change Low to moderate contribution with Low to Low to moderate moderatecontribution contributionwith with part catchment. part catchment. catchment. Coastle has low vulnerability Coastle has Coastle hasaaa low lowvulnerability vulnerabilitytoto to impacts climate change impacts climate impacts climate change Properties Properties at at at N Type Type Type Residential Residential Non-residential Non-residential Non-residential Low Characteristics Characteristics Characteristics 14.1km22 Total Area Total 14.1 Total Area Area 14.1 km km2 Land cover Land cover Land withcover Agriculture with Agriculture with Agriculture 50% 13% 13% 33% 33% 33% 14% 14% 14% No No No Number Number Proportion Proportion All All All Properties Properties Includes Defence(s) Includes Includes Defence(s) Defence(s) % 2% 1% 1% Hydrology Hydrology Hydrology Towns and Villages Towns and Villages with Properties atat Villages with withproperties Propertiesat Morphology Morphology Morphology Insufficient mation available Insufficient available Insufficient mation mation available Text Text Text data used. Insufficient mation available Insufficient mation mation available available Insufficient Text Text Text data used. February The mation this datasheet is based on December The mation this is December this datasheet datasheet is based based on on National2011. The mation Assessment.Please read datasheet National Assessment. Please read datasheet National Assessment. Please read datasheet conjunction with Text followg pages. conjunction with explanatory text followg pages. conjunction with explanatory text followg pages. 1

2 Potentially Vulnerable Area Datasheets: Text Please refer to terms and conditions use mation contaed with se datasheets. These are available on SEPA website 1. A written copy can also be obtaed on request from SEPA. The datasheets provide a summary different elements that have been used with National Assessment to identify Potentially Vulnerable Areas (s). A datasheet is provided each Potentially Vulnerable Area. This Text provides furr mation on categories used on datasheet and a defition key technical terms. Title Bar : Identifier number applied to Potentially Vulnerable Areas, mat Local Plan District no./ Potential Vulnerable Area no. (e.g. 03/05). Local Plan District: Local Plan District identifier with a name and number. The unique Local Plan District number is used to identify Potentially Vulnerable Areas with Local Plan District. Ma : Name ma river catchment(s). Local Authority: The name any local authority which lies with Potentially Vulnerable Area. An dividual Potentially Vulnerable Area can cross multiple local authority boundaries. and Impacts Summary Potential Impacts A broad statement providg an dication what is impacted by floodg with an area. The statements give an dication : The impact on four ma groups risk receptors; Human Health, Economic Activity, Environment and Cultural Heritage. Past floods which have been reported to local authorities or SEPA or collated from published sources by SEPA. If y have been reported a date or range identifyg first and last reported event is cluded. The location any known flood defences from Scottish Defence Asset Database and reference to structures that restrict flow which have been noted by local authorities. 1 Terms and conditions use mation from National Assessment can be found on SEPA website: 2

3 Defitions key terms used this category are provided below: Term Defition Less resilient Sensitive Environmental designation Designated cultural sites An area which may take a long time to re-establish or repair after a significant flood event. An area which may not re-establish or be repairable after a significant flood event. Areas designated natural heritage purposes such as Sites Special Scientific Interest (SSSIs), Special Areas Conservation (SAC) and Special Protection Areas (SPAs). Cultural sites such as listed buildgs and UNESCO World Heritage Sites. Estimated Weighted Annual Average Damages A strategic level estimate flood risk damages calculated usg Multi-Coloured Handbook 2. The Weighted Annual Average Damages (WAAD) figure gives an dicative estimate direct costs to residential properties, nonresidential properties and agriculture. It cludes benefit fered to residential and nonresidential properties by flood protection schemes but does not clude benefit from flood warng schemes. These figures are dicative and have been derived usg nationally held datasets. Care should be taken when applyg se figures locally. They will be subject to change as a result subsequent more detailed assessments and improved research on impact floodg. A refed set dicative figures will be published as part SEPA s Management Strategies Known Sources g A diagram showg overall fluence flood sources, expressed as a percentage, National Assessment. The diagram does not clude fluence groundwater, climate change or flood defences. The table below describes sources floodg more detail: source Surface water Impact from Watercourses. The effects structures or small watercourses are not cluded. Estuaries and sea based on projected still water levels. Wave overtoppg is not cluded. Pondg surface water followg heavy rafall. Bow waves from vehicles and flow pathways are not cluded. Groundwater g Potential - Identifies areas where groundwater floodg may be a contributg factor to flood risk, eir by causg floodg or by exacerbatg floodg from anor source. For example, by prolongg or creasg extent a river flood. 2 The Multi-Coloured Handbook is produced on behalf Environment Agency and Defra by Hazard Research Centre at Middlesex University. The use Handbook is recommended benefit assessment as part flood and coastal erosion risk management appraisal. Furr mation on Handbook is available at: 3

4 A gradg structure has been applied to describe potential contribution groundwater floodg to flood risk. The categories are listed below: Potential Contribution Greatest Lowest High to very high contribution with part catchment. Moderate to high contribution with part catchment. Low to moderate contribution with part catchment. Very low to low contribution with part catchment. Predicted Impact Climate Change A broad summary catchment sensitivity to climate change impacts. Climate change predictions dicate that parts Scotland may experience wetter wters and more extreme wear events cludg tense rafall summer months. This may lead to an crease damagg floods. Where a catchment is sensitive to impact climate change it may respond by producg a greater than proportionate run-f response to that experienced by an crease rafall. Conversely catchments which are less sensitive would exhibit a run-f response less than predicted crease rafall. A large proportion Scotland has neutral catchments where predicted crease run-f would be similar to crease rafall. The predicted impact climate change is described through followg phrases: Sensitivity Increase rafall and flow Impact on coastle Greatest Lowest Large crease rafall with proportionate crease run-f. Large crease rafall with potential a lower crease run-f. Moderate crease rafall with proportionate crease run-f. Low crease rafall with potential a larger crease run-f. High vulnerability to impacts climate Vulnerable to impacts climate Low vulnerability to impacts climate Not vulnerable to impacts climate Properties at The number, and proportion total number, expressed as a percentage, residential and non-residential properties with a Potentially Vulnerable Area which have been identified as beg at risk floodg. Towns and Villages with Properties at Each town and village where 50 or more residential properties are shown to be at risk floodg. 4

5 Characteristics Total Area The area square kilometres Potentially Vulnerable Area. Land Cover with Land use statistics based on CORINE3 data is provided, Agriculture and as a percentage total area. The areas are based on CORINE Level 1 categories. As an amalgamation categories reported figures may be greater than expected dividual categories. This may be less than 100% with remader made up or land use types 3. Term Artificial surfaces, cludg urban, dustrial and construction areas. Agriculture Pasture, arable and heterogeneous agricultural areas 4. and semi-natural areas. Includes Defence(s) States if mal flood defences have been identified with Potentially Vulnerable Area. 113 flood protection schemes have been corporated to National Assessment from Scottish Defence Asset Database. The central pot location defences has been used to determe if a defence is present with area. The true extent defence or area benefitg from defence may not be fully with Identified catchment 5. Hydrology A broad statement which provides a summary catchment hydrology characteristics which could affect flood risk. Available and readily derivable mation was used to identify important controllg or fluencg factors on flood hydrology such as relative floodpla storage, overall catchment storage potential and catchment responsiveness, which would aid identification areas that may be more susceptible to floodg. The statements used to describe catchment hydrology are below: 3 More mation on CORINE data set and land cover classes is available at 4 Heterogeneous agricultural areas are areas mixed agriculture. 5 Additional details are available at 5

6 Response Flashy Unresponsive Short peak flood flow response Very low catchment flood storage and attenuation capacity Potential significant underestimation design flood magnitude Very high erosion hazard potential flood flows Short to moderate peak flood flow response times Low catchment flood storage and attenuation capacity Potential high underestimation design flood magnitude High erosion hazard potential flood flows Moderate peak flood flow response times Moderate catchment flood storage and attenuation capacity Potential moderate underestimation design flood magnitude Moderate erosion hazard potential flood flows Moderate to long peak flood flow response times High catchment flood storage and attenuation capacity Potential low to moderate underestimation design flood magnitude Low erosion hazard potential flood flows Long peak flood flow response times Very high catchment flood storage and attenuation capacity Very low potential underestimation design flood magnitude Very low erosion hazard potential flood flows Morphology A broad statement which provides a summary catchment morphology characteristics which could affect flood risk. Available mation was used to categorise how potential impact channel engeerg could affect flood risk. This considers potential structures such as bridge piers and pipeles, culverts, weirs, flow deflectors, channel realignment, embankments etc. to crease flood risk upstream or downstream. These features may not be accurately represented with strategic modellg and lead to greater uncertaty results. The table below shows level uncertaty statements used on datasheets: Modellg Uncertaty Greatest Lowest Predomance meanderg/braided channel types Predomance natural channels and/or unprotected floodplas Very high density hydraulic structures Very high potential creased flood risk due to upstream morphological pressures High proportion meanderg/braided channel types High proportion natural channels and/or unprotected floodplas High density hydraulic structures High potential creased flood risk due to upstream morphological pressures Mixture meanderg/braided channel types and bedrock/plane-bed channel types or lochs Mixture natural/realigned channels and protected/unprotected floodplas Moderate density hydraulic structures Moderate potential creased flood risk due to upstream morphological pressures High proportion bedrock/plane-bed channel types or lochs High proportion realigned channels and/or protected floodplas Low density hydraulic structures Low potential creased flood risk due to upstream morphological pressures Predomance bedrock/plane-bed channel types or lochs Predomance realigned channels and/or protected floodplas Very low density hydraulic structures Very low potential creased flood risk due to upstream morphological pressures 6