Kilcormac, Co. Offaly Unique ID
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Location: Kilcormac, Co. Offaly Unique ID: 253051 (from PFRA database) Initial OPW Designation APSR AFRR IRR Co-ordinates Easting: 218372 Northing: 213942 River / Catchment / Sub-catchment Silver River / Brosna / Shannon Type of Flooding / Flood Risk Fluvial non-tidal Fluvial tidal Coastal (identify all that apply) Stage 1: Desktop Review River Flow Path 1.1 Flood History The Silver River flows through the north of Kilcormac and heads west and (include review of then north until it turns into Island River before joining the River Brosna. Floodmaps.ie) The Silver River is crossed at two locations within the Kilcormac town boundary. One is by the N52 (Bridge Street) and the other by Bridge Street adjacent to the Kilcormac Main Street. A tributary to the Silver River is crossed by the Ballyboy Road situated southeast of the Kilcormac village centre. Flood Event Records Two flood records are listed in floodmaps.ie. Both are dated January 1995. Review of reports indicates that flooding was from a drainage ditch which flows into the Silver River. This ditch is east of the town centre and flows north towards the Silver River. Indications are that the ditch was under capacity resulting in flood water coming out of bank and flowing overland towards the town of Kilcormac. PFRA database comments (in italics) : 1.2 Relevant information on OPW comments flooding issues from Designated APSR on the basis of predictive analysis and LA comments. OPW and LA staff Historic (2 dated floods with property flooding) - Predictive mapping error LA comments Housing estates by the river. Remove Fire Station score from PFRA analysis as it is closed. Meeting / discussion summary comments: OPW comments • Silver river flows through Kilcormac. • Bord Na Mona houses upstream of the town on the left bank are potentially at risk of flooding. LA comments • LA indicated that they were unaware of any flooding in Kilcormac. Flood Risk Review Report – UoM 25 26 Kilcormac V0_A 1 1.4 PFRA Data 1.4.1 PFRA hazard PFRA mapping available in GIS layer: Yes No mapping PFRA mapping included on FRR map: Yes No 1.4.2 Summary of Type FRI score Principal Receptors (if available) Receptors not considered as part of the PFRA process. FRI score not calculated in PFRA. 1.7 Stage 1 Aspect Clearly APSR Uncertain Evaluation Flood History (1.1) X OPW / LA Information (1.2) X PFRA Evaluation (1.4) X Overall Desktop Evaluation (if any above aspect is uncertain X then overall designation is uncertain) 1.8 Proposed level of Level A Site Visit X assessment for Stage 2 site visits Level B Site Visit Flood Risk Review Report – UoM 25 26 Kilcormac V0_A 2 Stage 2: Site Inspection Level A Assessment Date:21/04/11 Date and Time of Inspection Time: 14:00 Peter Smyth Names of inspection team (including OPW/LA staff if present) James Murray 2.1 Ground- Fluvial non-tidal Fluvial tidal Coastal Not available truthing of Hazard Mapping PFRA hazard mapping indicates no flood risk from the Silver river which appears to be an underestimate. Flood risk from the drainage ditch east of Kilcormac may also be underestimated – based on comments re: 1995 flooding. 2.2 Spot check Receptor Type Location description Exists? Overall ground-truthing of (if not obvious) Vulnerability selected receptor / Risk vulnerability (L / M / H) Private dwellings Properties upstream of Yes Medium (also note any key Kilcormac on left bank, receptors noted also on left bank during visit that are immediately downstream not identified by of N52 road bridge. PFRA) Housing south of town that previously flooded Petrol station On right bank upstream of Yes Medium N52 road bridge 2.3 Local No on-site comments. knowledge - on-site comments (OPW, LA and any info volunteered by local residents during visit) 2.4 Comments on There are two main bridges in the town with reasonable expectation not to hydraulic constrict flows. There is a further foot bridge in the town but it poses no constrictions hydraulic constriction as it would be bypassed in a flood event. (bridges, etc.) and conveyance routes Flood Risk Review Report – UoM 25 26 Kilcormac V0_A 3 2.5 SVRS Assessment Matrix Weightings: A - x1 - reasonable expectation of flooding B - x2 - high expectation of flooding C - x5 - risk to life Approx. Number 1 to 4 5 to 20 >20 Weighting A B C A B C A B C Property 10 100 X 200 (domestic) Property 20 200 400 (small retail or business) Property 50 500 1000 (large retail or business) Road or Rail Infrastructure 30 X 300 600 Critical Infrastructure (local) 50 X 500 1000 [hospital, school, police/fire/ambulance station, substation, WTW/WWTW, gov bldg, other (specify)] Critical Infrastructure (national 250 1000 2000 importance) Cultural Heritage Site 20 X 200 400 Environmental Designated Site 20 200 400 Hazardous Substances Site 50 500 1000 Total SVRS 200 2.6 Defence Assets Formal and Open Channel Watercourses Informal Flood Man-made river channel Flood relief channel Canal Defence Assets Mill leat Drainage channels / back drains (include effective and ineffective Bridges and Culvert crossings assets to inform Single Arch bridge Multi-Arch bridge asset survey and Single Span bridge Multi-Span bridge potential Box culvert(s) Pipe culvert(s) Arch Culvert(s) mitigation measures) Culverted Watercourses (culvert length is greater than just a crossing) Box culvert(s) Pipe culvert(s) Arch Culvert(s) Irregular Culvert(s) Walls and Embankments Embankment(s) Raised wall(s) Retaining wall(s) Control Structures – weirs, gates, dams Fixed crest weir Adjustable weir Dam / Barrage Sluice gates Lock gates Radial gates Storage On-line storage (natural) On-line storage (artificial) Off-line storage Outfalls Flapped outfall(s) into watercourse Unflapped outfall(s) into watercourse i.e. from smaller watercourses, drains etc. into river / estuary / sea Tidal flap(s) Tidal sluice(s) i.e. from main watercourse into estuary / sea Flood Risk Review Report – UoM 25 26 Kilcormac V0_A 4 Other Pumping Station Erosion Protection Sand Dunes Additional notes (if required): 2.8 Initial Potential Mitigation Measures Non-structural Planning and Development control measures Sustainable Urban Drainage Systems Flood forecasting / warning Change in Operating Procedures for water level control: Public awareness campaign Individual property protection Land use management Structural Strategic development management for floodplain development: measures (integration of measures into strategic development proposals) Storage: On-line Off-line Flow diversion: Flood relief channel Flood relief culvert Increase conveyance: Bridge works Channel works Floodplain Flood defences: Walls Embankments Localised works: Defence raising In-fill gaps Trash screen Maintenance works: Culvert / channel clearance Asset maintenance Relocation of properties: Improve existing defences: (describe) Other (describe): Outcomes PFRA Designation APSR not an APSR IRR FRI Score: Not scored Site Ground-truthing of High Uncertain Low Not available PFRA Assessment Confidence Confidence (hazard mapping and (good) (poor) receptors) X Site Visit Review Score 200 Recommended APSR not an APSR IRR Designation Summary Comments Kilcormac is recommended as an APSR on the historical evidence of (if required) flooding and the number of critical receptors significantly at risk from fluvial flooding. Flood Risk Review Report – UoM 25 26 Kilcormac V0_A 5 Photo1: Bridge over Silver River upstream Photo 2: Silver River through Kilcormac. of Kilcormac. Photo 3: Silver River through Kilcormac. Photo 4: Bridge over Silver River downstream of Kilcormac. Flood Risk Review Report – UoM 25 26 Kilcormac V0_A 6 216500 217000 217500 218000 218500 219000 219500 220000 Kilcormac 0 0 5 5 1 2 ± 0 0 0 5 1 2 Legend 0 0 APSR Boundary Rail Network 5 4 1 for CARs only 2 Roads Historic Flooding (National Roads Authority) @@! Incidents Airport Land Water bodies mapped OPW Embankments from RADARSAT-2 * Historic Flood Data H Hydrometric Gauging G ! Stations Architectural Heritage ^_ UNESCO Sites 0 EPA River Network 0 0 4 R Special Protection Area 1 ! Rail Stations 2 Special Area for N ! Nursing Homes Conservation Residential Care N Proposed National ! for the Elderly Heritage Area !E Schools National Heritage Area !] Ports and Harbours Benefiting Lands Flood Extents (PFRA, 2010) 0 0 !O OPW Buildings 5 ! 3 10% AEP Flood Extent 1 2 !!H Health Centres (1 in 10 chance in any given year) !G Garda Stations 1% AEP Flood Extent !H Hospitals (1 in 100 chance in any given year) !F Fire Stations 0.1% AEP Flood Extent # Civil Defence (1 in 1000 chance in any ! Head Quarters 0 given year) 0 0 o 3 ! Airports * Data Source - Service Régional de Traitement d’Image et de 1 2 Télédétection (SERTIT) (acquired on the 5th of December 2009). Client Project Shannon CFRAM Study 0 0 The PFRA Flood Extents shown are indicative. They have been developed using Flood Risk Review Map 5 2 Title 1 simple and cost-effective methods that are suitable for the PFRA. They should not be Kilcormac 2 used for local decision-making or any other purpose without verification. 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