Preliminary Flood Risk Assessment Report - Merthyr Tydfil County ...

MERTHYR TYDFIL COUNTY BOROUGH COUNCILPreliminary Flood Risk Assessment Report (PFRA)April 2011

Preliminary Flood Risk Assessment ReportExecutive SummaryUnder the Flood Risk Regulations (2009) and the Flood and WaterManagement Act became law in April (2010) Merthyr Tydfil Council BoroughCouncil (MTCBC) has been identified as a Lead Local Flood Authority (LLFA)and has been given a number of key responsibilities, including the preparationof a Preliminary Flood Risk Assessment Report (PFRA).To satisfy the Regulations MTCBC have identified a number of Partnersincluding The Environment Agency Wales (EAW), Dwr Cymru / Welsh Waterand the emergency services from outside of the Authority and EmergencyPlanning Section, Planning Section, Highways Division and Land DrainageDivision within the Authority. Significant quantities of data have been collectedfrom these partners.The Environment Agency has identified an indicative Flood Risk Area withinMTCBC of 45 km 2 . This area has been reviewed by MTCBC using all theinformation collected and consequently the Flood Risk Area has been increasedto 58 km 2 .Preliminary Assessment Report - MTCBC - Final103/06/2011

Preliminary Flood Risk Assessment ReportContentsFiguresTablesPageExecutive Summary 11 Introduction 32 Lead Local Flood Authority Responsibilities 53 Methodology and Data Review 74 Past Flood Risk 105 Future Flood Risk 126 Review of Indicative Flood Risk Area 147 Identification of Flood Risk Area 158 Next Steps 179 References 18Fig. 1 All Wales Map 20Fig. 2 EAW Indicative Flood Risk Area and Blue Squares for MTCBC 21Fig. 3 MTCBC Flood Risk Area and Blue Squares for MTCBC 22Fig. 4 MTCBC Flooding Incidents and Historic Flooding 23Fig. 5 MTCBC Blue Square X304Y207 24Fig. 6 MTCBC Blue Square X307Y201 25Fig. 7 Areas Flooded during December 1979 Flood 26Fig. 8 MTCBC Flood Map for Surface Water 1 in 200 year 27Table 1 – Key Flood Risk Indicators 7Table 2 – Data Collected 8Table 3 – Details of the December 1960 Flood 11Table 4 – Details of the December 1979 Flood 11AnnexesAnnex 1 Record of past floods 19Annex 2 Future floods 19Annex 3 Flood Risk Area 19Annex 4 Review checklist 19Annex 5 – GIS Layer of Flood Risk Area 19Appendices1 Information for reporting on Flood Risk Area 20Preliminary Assessment Report - MTCBC - Final203/06/2011

Preliminary Assessment Report1 Introduction1.1 The Flood Risk Regulations came into force in December 2009 and the Flood andWater Management Act became law in April 2010. Under this legislation Merthyr TydfilCouncil Borough Council (MTCBC) has been identified as a Lead Local Flood Authority(LLFA) and has been given a number of key responsibilities.1.2 The purpose of the Flood Risk Regulations is to transpose the European Commission(EC) Floods Directive (2007/60/EC), on the assessment and management of local floodrisk, into domestic law in England and Wales and to implement its provisions.In particular it places duties on the LLFAs to prepare a number of documentsincluding:-Preliminary Flood Risk Assessment Report 22 nd June 2011Flood Hazard and Flood Risk Maps 22 nd June 2013Flood Risk Management Plans 22 nd June 20151.3 The purpose of this Preliminary Flood Risk Assessment Report is to identify areassubject to significant flood risk within Merthyr Tydfil County Borough Council. Thisinformation will then be used to inform the later stages of the Regulations including theFlood Hazard and Flood Risk Maps and the Flood Risk Management Plans.1.4 It is the responsibility of the Lead Local Flood Authorities (LLFA) to consider the riskfrom the following sources:-1. Ordinary watercourses2. Surface runoff3. Groundwater4. And any interaction these have with drainage systems and other sources offlooding.The report does not consider flooding from main rivers, the sea or large raisedreservoirs, which are the responsibility of the Environment Agency.1.5 The area identified as being subject to significant risk is referred to as The Flood RiskArea.The PFRA report must consider floods which have significant harmful consequencesfor human health, economic activity and the environment.1.6 Merthyr Tydfil County Borough Council (MTCBC) is a Unitary Authority situated withinthe valleys of South East Wales. It has a population of approximately 56,000 and anarea of 11,189 hectares. The Borough is a mix of rural and urban communitiesgenerally built on the steeply sloping hillsides or within the valley basins.See Fig 1. All Wales Map.1.7 The study area is served by one water company – Dwr Cymru / Welsh Water and hasone major catchment which drains into the River Taff.1.8 The PFRA is a high level screening exercise to locate areas in which the risk of surfacewater and groundwater flooding is significant and warrants further examination throughthe production of flood hazard and risk maps and management plans.Preliminary Assessment Report - MTCBC - Final303/06/2011

The aim of the PFRA is to provide an assessment of the local flood risk across thestudy area, including information on past floods and the potential consequences offuture floods.The key objectives may be summarised as follows:-1. Identify relevant partners involved in future assessment of flood risk andsummarise means of stakeholder engagement.2. Describe arrangements for partnership and collaboration for the collection,assessment and storage of flood risk data.3. Provide a summary of the systems used for data sharing and storage, andprovision for quality assurance, security and data licensing arrangements.4. Summarise the methodology adopted for the PFRA with respect to datasources, availability and review procedures.5. Assess historic flood events within the study area resulting from surfacewater, groundwater and ordinary watercourses together with theconsequences and impact of these events.6. Collect and integrate historic information, which will be built upon in thefuture and used to support and inform the preparation of the MTCBC LocalFlood Risk Strategy.7. Assess the potential harmful consequences of future flood events within thestudy area.8. Review the provisional national assessment of the Indicative Flood RiskArea provided by the EAW and provide explanation and justification for anyamendments required in order to produce the final Flood Risk Area.Preliminary Assessment Report - MTCBC - Final403/06/2011

2 Lead Local Flood Authority Responsibilities2.1 In order to satisfy MTCBC’s governance procedures a preliminary report outlining therequirements of the Flood Risk Regulations and the Flood and Water Management Act,and giving details of the responsibilities of MTCBC as a LLFA was presented to theScrutiny Committee in March 2011.The Preliminary Flood Risk Assessment Report, details of the Flood Risk Area and thePreliminary Assessment Report Spreadsheet will be placed before the Cabinet, fullCouncil and Scrutiny Committee of Merthyr Tydfil Count Borough Council on prior tothe final completion deadline of 19 th August 2011.2.2 As part of the PFRA MTCBC has sought to engage partners which includes thoselisted below:-1. The Environment Agency Wales (EAW)2. Dwr Cymru / Welsh Water (DCWW)3. Local Emergency Services – including fire and police.In addition significant collaboration has been stimulated between the variousdepartments within MTCBC as listed below:-1. Emergency Planning Section2. Planning Section3. Highways Division4. Land Drainage Division.In addition significant interaction and collaboration has been established withneighbouring LLFAs within South East Wales.2.3 It is recognised that members of the public may also have valuable information tocontribute to the PFRA and the Local Flood Risk Strategy. Collaboration with the publiccan afford significant benefits including building trust, gaining access to additional localknowledge and increasing the chance of stakeholder acceptance of the local riskmanagement plans.To date the public have not been engaged on this project but the importance ofcollaboration is recognised. It is proposed that MTCBC will follow the guidelinesoutlined in the Environment Agency’s “Building Trust with Communities” publicationwhich provides a useful process to communicate risk including the causes, probabilityand consequences to the general public and professional forums.Preliminary Assessment Report - MTCBC - Final503/06/2011

2.4 In addition to the Preliminary Flood Risk Assessment Report, Flood Hazard and FloodRisk Maps and Flood Risk Management Plans the Flood and Water Management Actand the Flood Risk Regulation have placed on Lead Local Flood Authorities a numberof other significant responsibilities including the following:-1. Investigating and recording flood incidents and significant floodingevents - including the identification of which authorities have flood riskmanagement functions and what they have done or intend to do withrespect to the incident. Notifying the risk management authorities wherenecessary and publishing the results of any investigations carried out.2. Maintain an Asset Register of features or structures which areconsidered to have an affect on flood risk, including ownership andcondition.3. SuDS Approving Body (SAB) - to approve, adopt and maintain any newsustainable drainage system.4. Local Strategy for Food Risk Management - develop, maintain, applyand monitor the strategy.5. Work Powers - The LLFA have powers to undertake work to manage floodrisk.6. Powers to Designate Structures which may affect flooding in order tosafeguard assets that are relied upon for flood risk management.Preliminary Assessment Report - MTCBC - Final603/06/2011

3 Methodology and Data Review3.1 The following organisations were identified and contacted to obtain information for thepreparation of the PFRA:-Environment Agency – WalesGeoStoreNational Receptor DatasetUtilitiesDwr Cymru/Welsh WaterWestern PowerBritish TelecomEmergency ServicesFire ServicePoliceWithin Merthyr Tydfil CB CouncilPlanning SectionEmergency Planning SectionIT Section - GISLand Drainage DivisionHighways DivisionTable 1 - Key Flood Risk IndicatorsImpact of flooding onHuman HealthEconomic ActivityCultural HeritageEnvironmentalFlood Risk IndicatorsNumber of residential propertiesCritical Services including hospitals, police,fire and ambulance stations, schools, nursinghomesNumber of non-residential propertiesLength of road or railArea of agricultural landAncient MonumentsListed BuildingsDesignated sites – SSSIs and SINCsNature reservesLandscape of historic interestThe above indicators have been selected by Defra, WAG and the Environment AgencyWales in order to identify areas where flood risk and potential consequences exceed apre-determined threshold. Indicative Flood Risk Areas have been identified where morethan 5,000 people are at risk of flooding.Preliminary Assessment Report - MTCBC - Final703/06/2011

Table 2 – Data CollectedEnvironment Agency - WalesUtilitiesDataAreas Susceptible to SurfaceWater FloodingDescriptionFirst generation national mapping, outlining areas of riskfrom surface water flooding with three susceptibilitybandings - less, intermediate and moreSecond generation national surface water flood mappingFlood Map for Surface Water which includes two sets of data - 1 in 30 and 1 in 200year rain fall events with two bandings for each - greaterthan 0.1m and greater than 0.3mFlood Zones Maps showing flood zones 2 and 3Areas Susceptible toCoarse scale mapping showing areas susceptible toGroundwater Flooding groundwater floodingHistoric Flood Map 22 Showing locations of areas of past floodingThis data set gives details of social, economic,National Receptor Dataset environmental and cultural receptors including residentialproperties, schools, hospitals, and electrical substationsEAW Blue SquareIndicative Flood Risk AreaRiver networkFlood defencesHistoric Sewer FloodingHistoric Surface WaterFloodingCulturalEnvironmentalHistoric landfillWelsh Water DG5 RegisterWelsh Water ServicesWestern PowerBritish TelecomSquares which the EAW have identified as beingsusceptible to flooding of significant consequencesNationally identified flood risk area based on the DefradocumentationMap of main riversLocation of existing flood defences and land protectedLocation of incidents of fouls sewer floodingLocation of incidents of surface water floodingCoarse scale map of listed buildings and scheduledmonuments at risk of floodingCoarse scale maps of PPC sites with potential risk offlooding,Areas used for land fillIncidents of flooding within properties and severe externalLocation of pumping stations, service reservoirs andtreatment worksLocation of substationsLocation of telephone exchangesEmergencyServicesMerthyr Tydfil CB CouncilFire ServicePoliceLand Drainage DivisionPlanning Section - culturalPlanning Section -environmentalIT Section - GISEmergency Planning SectionEmergency Planning SectionHighways DivisionIncidents of floodingIncidents of floodingIncidents of flooding to propertyAreas of historic floodingListed buildings, ancient monuments,SSSI, nature reserve, SINC, landscape of historic interestContours at 5m intervalsIncidents of flooding to propertyLocation of schools, care homes, doctors surgeries, firestations, police stations, ambulance stations,Highway classification and routesPreliminary Assessment Report - MTCBC - Final803/06/2011

3.2 Information from the Environment Agency Wales was readily available on CD, emailand down loads from the EAW GeoStore. This information was in a form which allowedit to be easily imported into our GIS system.Incidents of flooding from Dwr Cymru / Welsh Water were provided on request andwere in a form which allowed easy importation into our GIS.Their asset location data which arrived much later was also received in a suitableelectronic format.Locations of services from British Telecom and Western Power were in paper formatwith no grid references and therefore had to transposed into a form suitable for use in acomputerised GIS.Flooding incidents from the emergency services were limited in number and in paperformat without grid references. These data sets all had to be re-entered in electronicformat.Flooding incidents from the Engineers were limited in numbers, in paper format andwithout grid references. This data had to be re-entered in electronic format. There areconsiderable gaps in this information where years of records have been misplaced.Further searches may reveal additional data during the preparation of the Local FloodRisk Strategy. Although this information is incomplete the data we have is consideredto have a high confidence rating in terms of its reliability.The historic flooding areas have been identified from the personal knowledge of staffwithin the Drainage Section, and although incomplete, is it regarded as being of a highquality.Information from the Emergency Planning Section was in a format incompatible withGIS and therefore had to be transposed into a suitable electronic format.Information from the Highways Division and Planning Section was in electronic formatand readily imported into GIS.It is the intension of MTCBC to gather more information on future flooding incidentswhich will be in electronic format suitable for importation into our GIS system.3.3 We currently operate with ArcMap GIS system and all our information is now stored inelectronic format suitable for importation as layers within ArcMap. For easy input ofdata we are currently using Microsoft Excel Spreadsheets and Microsoft Word as aword processor.3.4 Although the amount of data recording past incidents of flooding and historic flooding islimited, Fig. 4 MTCBC Flooding Incidents and Historic Flooding shows a high degree ofcorrelation between these data sets and the Blue Squares identified by the EAW andMTCBC.3.5 The information received from the EAW is restricted by the terms imposed by them.Information provided by MTCBC on Ordinance Survey maps is subject to the normallicensing agreement with them.We are not aware of any other restrictions on the data available to MTCBC.Preliminary Assessment Report - MTCBC - Final903/06/2011

4 Past Flood Risk4.1 Data of incidents of past flooding has been collected for this report as detailed inSection 3 above.To decide on the significance of an individual flood Defra/WAG/EA have set key floodrisk indicator which define a Flood Risk Area in Wales as having 5,000 people at risk oran individual 1km square where at least 200 people or 20 businesses or more than 1critical service might be flooded to a depth of 0.3 metres and above by a rainfall eventwith a chance of 1 in 200 of occurring in any given year.MTCBC as a LLFA has set the key flood risk indicator of people at risk of flood at athreshold of 200(equivalent to 85 properties) to decide if a flood is of local significance.A flood event of this magnitude is at least one level of consequence down from thenational threshold but still represents a flood of considerable magnitude. Such a floodcould occur as a very intense localised area such as a 1km square or cover the wholeof the borough in a less intense rainfall event.The data readily available has been analysed to give the number of properties floodedin each incident and there are no records of flooding which affects 85 or moreresidential properties. And therefore no floods have been recorded as a result of thisprocess.4.2 Two floods have been identified as being locally significant within Merthyr Tydfil CountyBorough Council. These have been identified from reports prepared following majorfloods. The two floods are:-1 4 th December 19602 26 th December 1979Both these flood events have been entered into the Preliminary Assessment ReportSpreadsheet – Annex 1 – Past floods and extracts from the spreadsheet are givenbelow.4.3 Details of December 1960 Flood.Information about this flood event has been taken from a report prepared by theGlamorgan River Board.Precise details of the areas flooded were not given and therefore no plan has beenproduced of this flood.Preliminary Assessment Report - MTCBC - Final1003/06/2011

Table 3 – Details of the December 1960 FloodSummary DescriptionOn 3 and 4 December 1960 serious flooding took place throughout MTCB Counciland the whole of Wales. The flooding followed a period since June 1960, during whichthere were a record number of wet days.The ground was therefore super-saturated.During November 1960 263mm of rainfall was recorded at Dowlais, which is within theFRA, and 525mm at Brecon, which is 25 km north of the FRA. This was the highestmonthly rainfall recorded since 1885. A further 132mm of rain was recorded at Breconon 3 December 1960.The conditions in the Taff were the worse in living memory with water levels above the1929 flood and had probably not been exceeded for over 100 yearsHuman Health ConsequencesA total of 90 residential properties were flooded in addition to the following1 Public house flooded; 2 shops flooded; 22 major roads or supporting wallsdamaged; 2 culverts damaged; 2 footbridges over the River Taff damaged; 1 gasmain damaged; 1 water main damaged4.4 Details of December 1979 Flood.Information about this flood event has been taken from a report prepared by theRobinson Jones Partnership Ltd.Details of the areas flooded are shown in Fig. 7 Areas Flooded during December 1979Flood.Table 4 – Details of the December 1979 FloodSummary DescriptionFollowing heavy rainfall on the 26th and 27th December 1979 flooding occurred overa wide area of Wales causing extensive damage. It is estimated from Welsh WaterAuthority records that, in Pentrebach and Troedyrhiw catchment areas, both of whichare in the FRA, between 113mm and 140mm or rain fell.This storm was preceded by two other significant storms during the month ofDecember. The first storm between 4th and 10th December caused rainfall of 175mmto be deposited on the Brecon Beacons. Records of the second storm between, 15thand 19th December, shows over 100mm of rainfall over the Brecon Beacons.As a result of these earlier storms the catchment was totally saturated prior to thestorm on 26th and 27th December and significant parts of the upper catchments werefrozen. These facts resulted in a 100% runoff causing higher flows than wouldnormally be expected for a storm of this intensity.Human Health ConsequencesA total of 189 residential properties were flooded within 0.08323 km”In Pentrebach 43 houses, 1 Hotel and a cricket field flooded.In Troedyrhiw 146 houses flooded and a major culvert collapsed.In Rhydycar there were two fatalities as a result of a culvert collapsePreliminary Assessment Report - MTCBC - Final1103/06/2011

5 Future Flood Risk5.1 MTCBC has no information currently available relating to future flooding other than thatprovided by the EAW, as listed below. It is the intension of MTCBC to carry outelectronic modelling within the Flood Risk Area as part of the preparation of FloodHazard and Flood Risk Maps and the Flood Risk Management Plan for the borough.5.2 The Environment Agency has produced two sets of flood maps giving an assessmentof flood risk for the whole of England and Wales. The first generation mapping referredto as Areas Susceptible to Surface Water Flooding (AStSWF) containing three levels ofbanding with a 1 in 200 chance of occurring. A second generation of maps have sincebeen prepared and issued by the EAW referred to as the Flood Map for Surface Water(FMfSW). This revised model contains two flood events 1) 1 in 30 and 2) 1 in 200annual chance of occurring. Each data set is further subdivided to give areas likely toflood to a depth greater than 0.1m and greater than 0.3m.5.3 The EAW have carried out validation checks on the two mapping system and for thetype of terrain within MTCBC, which is mostly steeply sloping hillsides it is consideredthat the Flood Maps for Surface Water are the most appropriate to use for this PFRA.Fig. 8 MTCBC Flood Map for Surface Water 1 in 200 shows the flooding predicted bythis model.5.4 At this stage MTCBC does not have details of the capacity of the local drainage but thisinformation will be calculated as part of the preparation work for the Flood Hazard andFlood Risk Maps and the Flood Risk Management Plans.5.5 Annex 2 of the Preliminary Flood Risk Assessment Spreadsheet has been completedfor a 1 in 200 year storm flooding to a depth greater than 0.3m.5.6 As no other information is available the second generation of maps prepared andissued by the EAW referred to as the Flood Map for Surface Water (FMfSW). Havebeen accepted as the locally agreed surface water information.5.7 The impacts of climate changeThe impact of climate change on local flood risk is relatively poorly understood. Severalnational flood maps have informed the preliminary assessment report - specifically theFlood Map for Surface Water (surface runoff), Areas Susceptible to Surface WaterFlooding (surface runoff), Areas Susceptible to Groundwater Flooding (groundwater)and Flood Map (ordinary watercourses). These do not show the impact of climatechange on local flood risk.There was consensus amongst climate model projections presented in the IPCC fourthassessment report for northern Europe suggesting that in winter high extremes ofprecipitation are very likely to increase in magnitude and frequency. These modelsproject drier summers with increased chance of intense precipitation — intense heavydownpours interspersed with longer, relatively dry periods (Solomon et al., 2007).5.8 UKCP09United Kingdom Climate Projections 2009 (UKCP09) provides the most up to dateprojections of future climate for the UK (http://ukclimateprojections.defra.gov.uk/). Interms of precipitation, the key findings are:By the 2080s, under Medium emissions, over most of lowland UKPreliminary Assessment Report - MTCBC - Final1203/06/2011

7 Identification of Flood Risk Areas7.1 As part of the review carried out by MTCBC as noted above clause 6.5 two 1 kmsquares were identified as being Areas above the Flood Risk Threshold. They areX304Y207 and X307Y201.7.2 Grid square X304Y207 has been made into a blue square by MTCBC because thereare 4 critical services which have been identified as being at risk of flooding as listedbelow1 Goetre Infants School2 Goetre Junior School3 Cyfarthfa Junior School.All three are shown as being subject to flooding on the EAW Flood Map for SurfaceWater 1 in 200 year event depth >0.30m.4 St Aloysius RC Primary SchoolThis school has a culverted ordinary watercourse flowing through its grounds. If thegrid blocks, the culvert collapses or the flow of water is above the culvert capacity theschool would flood.As a result this square is defined as an Area above Flood Risk ThresholdAs a result of making this square blue, and using the Defra/WAG methodology, 5additional squares have been brought into the MTCBC Flood Risk Area.See Fig 3 MTCBC Flood Risk Area and Blue squares for MTCBC7.3 Grid square X307Y201 has been made into a blue square by MTCBC because thereare 3 critical services which have been identified as being at risk of flooding as listedbelow:-1 Troedyrhiw Pumping Station - which pumps combined sewage from 61residential properties2 Haven Close which provides sheltered accommodation for vulnerablepeople3 Afon Taf high School.All three critical services are shown as being subject to flooding on the EAW Flood Mapfor Surface Water 1 in 200 year event flooding > 0.30m deep.By making this square blue, and using the Defra/WAG methodology 6 additionalsquares have been brought into the MTCBC Flood Risk Area.See Fig 3 MTCBC Flood Risk Area and Blue squares for MTCBC.Preliminary Assessment Report - MTCBC - Final1503/06/2011

7.4 As a result of the above amendment the EAW blue square X307Y199 becomescontiguous with the MTCBC Flood Risk Area and therefore we consider it appropriatethat the Flood Risk Area should be increased to include this square.See Fig 3 MTCBC Flood Risk Area and Blue squares for MTCBC.7.5 On the basis of the 22 blue squares identified by MTCBC, 20 of which are within theMTCBC Flood Risk Area, and the methodology defined above, MTCBC have identifiedan indicative Flood Risk Area of 58 km 2. .See Fig 3 MTCBC Flood Risk Area and Blue squares for MTCBC.7.6 The Key Flood Risk Indicators for the MTCBC Flood Risk Area have been calculatedby the as follows:-Human health consequences –Number of people (2.23 multiplier) 7,923Other human health consequences –Number of critical services flooded 26Economic consequences – number ofnon-residential properties flooded 818See Appendix 1 – Flood Risk Area – Information for reporting on Flood Risk Area Datafrom EAW and MTCBC.Preliminary Assessment Report - MTCBC - Final1603/06/2011

8 Next steps8.1 In order to continue to fulfil the role as Local Lead Flood Authority, Merthyr Tydfil CBCouncil are required to investigate future flood events and ensure continued collection,assessment and storage of flood risk data.It is essential that all new records of flood events are documented in accordance withthe INSPIRE Directive (2007/2/EC). The format of the records will be compatiblebetween departments sections within MTCBC and will also be in an electronic formatsuitable for importation to our GIS system.8.2 A preliminary report has been submitted to the Scrutiny Committee of MTCBC. Thecommittee has decided that no further submission will be necessary before thePreliminary Flood Risk assessment report is submitted to the Environment Agency.Prior to the report being sent to the EAW it will be thoroughly reviewed within theEngineering Department.8.3 Under the Flood Risk Regulations the Environment Agency has been given a role ofreviewing, collating and publishing all PFRAs.The EAW will undertake a technical review of the PFRA which will focus on instanceswhere Flood Risk Areas have been amended and ensure the format of these areasmeets the appropriate standards. The PFRAs will finally be signed off by theEnvironment Agency Regional Director before they are signed off, collated, publishedand submitted to the European Commission.8.4 Following the submission of the PFRA by MTCBC, which must be completed by 22 ndJune 2011, work will commence on the flood Hazard and Flood Risk Maps, to becompleted by 22 nd June 2013 and finally the Flood Risk Management Plans to befinalised by 22 nd June 2015.Once this cycle has been completed the review procedure will commence which willresult in a more detailed Flood Risk assessment report being submitted to theEuropean Commission by 22 nd December 2017.Preliminary Assessment Report - MTCBC - Final1703/06/2011

9 ReferencesFlood and Water management Act 2010http://www.legislation.gov.uk/ukpga/2010/29/contentsThe Flood Risk Regulationshttp://www.legislation.gov.uk/sksi/2009/3042/contents/madePreliminary Flood Risk assessment (PFRA)Final GuidanceReport –GEH01210BTGH-E-EEnvironment Agencyhttp://publications.environment-agency.gov.uk/Preliminary Flood Risk Assessment (PFRA)Annexes to the final guidanceReport – GEH01210BTHF-E-EEnvironment Agencyhttp://publications.environment-agency.gov.uk/Selecting and Reviewing Flood Risk Areas for local sources of floodingGuidance to Lead Local Flood AuthoritiesFlood Risk Regulations 2009Defra / Welsh assembly Governmenthttp://ww2.defra.gov.uk/environment/flooding/Preliminary Assessment Report - MTCBC - Final1803/06/2011

AnnexesAnnex 1 - Records of past floods and their significantconsequences (preliminary assessment report spreadsheet)Refer to Annex 1 of the Preliminary Assessment SpreadsheetAnnex 2 - Records of future floods and their consequences(preliminary assessment report spreadsheet)Refer to Annex 2 of the Preliminary Assessment SpreadsheetAnnex 3 - Records of Flood Risk Areas and their rationale(preliminary assessment report spreadsheet)Refer to Annex 3 of the Preliminary Assessment SpreadsheetAnnex 4 - Review checklistRefer to Annex 4 of the Preliminary Assessment SpreadsheetAnnex 5 - GIS layer of flood risk areaGIS layer sent separately to the Environment AgencyPreliminary Assessment Report - MTCBC - Final1903/06/2011

Sir Ynys Mon - Isle of AngleseySir y Fflint - FlintshireConwy - ConwySir Ddinbych - DenbighshireWrecsam - WrexhamGwynedd - GwyneddPowys - PowysSir Ceredigion - CeredigionSir Benfro - PembrokeshireSir Gaerfyrddin - CarmarthenshireMerthyr Tudful -Merthyr TydfilAbertawe - SwanseaCastell-Nedd Port Talbot -Neath Port TalbotRhondda, Cynon, Taf -Rhondda, Cynon, TaffPen-y-bont ar Ogwr -BridgendBro Morgannwg -the Vale of GlamorganBlaenau Gwent -Blaenau Gwent Sir Fynwy -MonmouthshireTor-Faen - TorfaenCaerffili -CaerphillyCaerdydd -CardiffCasnewydd -NewportALL WALES MAPFig. 1April 2011NTSThis map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.¯Preliminary Assessment Report - MTCBC - Final2003/06/2011

EA INDICATIVE FLOOD RISK AREAAND BLUE SQUARES FOR MTCBCFig. 2April 2011NTSThis map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.¯Preliminary Assessment Report - MTCBC - Final2103/06/2011

X304Y207X307Y201X307Y199MTCBC FLOOD RISK AREAAND BLUE SQUARES FOR MTCBCFig. 3April 2011NTSThis map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.¯Preliminary Assessment Report - MTCBC - Final2203/06/2011

GGGGGGGGGGG GGG G GGGGGGG GGGGG GGG GGG GGGGG GGGGGGGGGGGGGGGGGGG G G GGGGGGGGGGGGGG GGG G GGGGGGGGGGGG GGGGGGGG GGGGGGGMTCBC FLOODING INCIDENTSAND HISTORIC FLOODINGFig. 4 NTS¯April 2011This map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.G GG GGGGGG GGGGGGGGGPreliminary Assessment Report - MTCBC - Final2303/06/2011

43465745615034Trou gh615FF659546534El Sub Sta64Trou gh51756192.6mPa ndyFarm1Paddli ngPool34PCTrack213.4mCl ock Tower36261.1mMini ature Railway23S M19LBPO58Playground31Issues52Cyfarthfa IndustrialEstateYstad DdiwydiannolCyfarthfa48PC482Works714725Tk142Cyfarthfa C astle(High School And Museum)12214.0m20535693940210.9mSinks452188618263267819416Stone13024 1.1mGV CSM1PondTenni s CourtTennis Court224.3m216Col lects304Williamstown1Castle WoodPond13274.9m187.8mPondPa vilionBowling Green9SubwayIss uesPC280.9m23Pond117265.2 m1252.7mPondCyfarthfa Park247Issues5020FW1126Issues42719Shelt er187.1m5720311 to 4293.8m381 t o 16Shelter611413Car P ark17 to 225 to 10 35 to 40Playgrou nd3623 to 28Bandstand(Di sused)269.4m8PostPr in ce C ha rle s Hosp ita lIssues1Devonshi re HouseShangri-La39ElSub Sta729 to 34Ys by ty Twy so g S iarlCast leView House76Churchdown188.7m41 to 4 65277.7m1Stone8811347 to 52Goe tre Coun ty Primary Sc hool204.8mPH4641483115519Pond53to589SM269.1m615175816ST69017191.4m52Hall192Gat e S treet8203.0m311Goitr e Junior a nd InfantsSchool4964293In n2FWSports Field211.2mPH20189.6mPrince Cha rle s Hospita lYs by ty Twy so g S iarl5FB13to16Grawen25265.5mPark Villa112241Pond1314252151FF18FB196.6mSubway19Tre bethan9257.6m7Gurnos NurserySchool208.2m227.4m2WE L L ST REE T192.6m20FWTy-Gwyn1916TheBunga low141366832ElSubStaSt AloysiusPrimary SchoolPath (um)12 161013ED Bdy319FF3625210114726W AY544Playgr ound250.9m2010bPath (um)32BLA CKT HO RN2AV EN UEROA D1WILL O W ROA D20818CS1381ALM O ND G RO VE118111213261023425137314323713119372510715291059279.5 mPlayin g FieldHaul fryn5Awe lf ryn1771929282013W AY97El Sub Sta301007242.9m1197.8 m16242 3 491 487319872420 5234116252420Sunday S chool1277114197623741Ael-Y-Bryn6191978761821075111261152634PAL MDepot17117176312WelfareHom eElSubStaFWLBArdwynPO P L AR162516WAY176115101926222121677064232.9m181618825851Commun it yCent reGurnos HouseCS84Allotment Gardens174205Shelt er49161633209.7 m192259264626154Bronygart h12100961498945435Hall276.9m34262715223.1 m7Club511392725232493437296984284.5m21719151410 538CarParkLBPO P L AR9225192372ElSub St aThe Firs81109212Rookwood231360PCPO30ElSub StaEL M213.7m32272345633225410931314121901227.4m5425Ash MountMaes-y-nant312186LIM E20516150CR252Pine TreeHouseGrove Park41141342LodgeTheCedarsElSubSta307731242381797542Sherwood422Brookside20Post s1220ElSub St a13342TCB52913BramblewoodGlyder204.8m138416971PenycwmLB4216112265.8m65671734315423185622114633212510RedlandsBrooklands5CLO S E53282091474Felin Newydd17432a210Melita HousePosts772West Winds13172NewlynRheidol116278ElSubSta2125043579217.3m520256.2 mThe Spinney29ST262212191838231.6m131970121164917767TCB289.6m9211145452692124a9248a20250 .0m1668182843241.0mFern wo od16122814257832154128311722660312437ChaseView1102315224.0m42MarlogGlenthorneH EA TH ER R OA DH E ATH E R OA DMA RIGO L D C LO S E!LAR CHCLO SE11ALD ERMA GN OL IAPL AN E GR O V EGRO V E2 4PlaygroundHON EY S U CKL E C LEl Sub StaHON E YS UCK L E C L OS EJAS M I NE CLO S E10 18 28GURNOSROA D3 41 to 1 221 19 13Polic e StationClinic16YEW C L OSE1 2CH EST NUT W AYCLO V E RROA DWA YChu rc hSt A l oy s ius R CBRA MB LEC LO SESP R UCE T RE E G RO VELAB URN UMCLO S EGU R NO S R OA DGoetre Infants SchoolGoetre Junior SchoolED B dySubway!Path! GUR NO SROW ANWAYMA P LECLO S EHOLLY W AYSY C AM O REROA DCHE RRYH AWT H O RNAV EN UEGUR NO SCyfarthfa ParkROA DACAC IA!CE DAROAKROA DAVE N UETrackSt AloysiusRCPrimary SchoolASHCRE S CE N TGRO V ETrackPath (um)Castle WoodTrackCyfarthfa ParkOA K R OA DGRO V E!GUR NO S R OADCyfarthfa JuniorSchoolTrackED Bdy2019GWA E LO DY G ART HCYFA R TH FA C OU RTHi lsideROO K W O OD CL O SEBR O OK LA NDS CL OS EGWA ELO DY G ARTH RO ADPar k Co ta g ePE N TW Y N V IL L ASMA R Y'S CL OS EHi l cro f tLy n wo o dPa rk Ro w G ard en sWE S T G RO VEBRECO NROA DMEY R IC K V IL LA S!MTCBA BLUE SQUARE X304Y207Fig. ! 5 NTS¯April 2011This map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.Slop ing masonryWorksPipe LineCY FAR TH FA R OA DRiv er Ta f(Afon Ta f)C yfar thfa J un io r Sc h o olEm ly n Ter rac eGr a we nSlop ing masonryGra we nCastle Sq ua reGW A E LO DYG ART H RO ADTYDFIL'SWELL7 Gra we nBRE CO N RO ADRIVE R S ID E P ARKMA RG AR E TWILLIAMSTOWNST RE ETPL E AS A NT VIE WPa rk Ro wCRO SSST RE E TMA RG ARE TPar k RowMIL E S19 20ST RE ETSt Ty dfil' sWe l C hu rchCHUR CHGra we nArm s1 572ST RE E T21 23TYDFIL'SWELLCRO SS6 1Tyd fil 's Te ra ce1 1018 197 88 12MO UN T ST RE E T281MO R G ANGRAW E NMO RG AN S T REE TTai r Gr awe n9toMo u nt Ter rac eST REETClyd an H o us eTE RR A C E1 131 to 8Br yn P er isMo u nt Te rac eMey ri ck H ous eBr yn Vi laTHEQUAR2 453 5410a1 734 to 3 61 7 13ST U A RT ST REE TCAR A DO C ST RE ETHANO VER STR E ET24 31LL EWE L LYNST REET1 5SA X ON S T RE ET616DANE ST R EET!NOR M AN T ER R AC E21 275 61 3D A NETER R A CE1 6 12LAN C AST E R STR EE THo u seE lm Tr eKIN G ED WAR D ST REE TTHE GRO V EPreliminary Assessment Report - MTCBC - Final2403/06/2011

284201037123955645934738624858912292361232712135224161723101121Pol Sta172128263132271617324871378120110484011111452122013933306121211392111512851CARDIFF ROAD147.8mCroesoBrynseionHawthornCottagePlas BrynteɵgCottageBryntegHi lcrestVillaFernhi lVillasBrynamlwgVillasMount PleasantCraig y PwllThe MorlosAsh VillasZion ClosePlas BrynteɵgRiver Taff (Afon Taf)Lower Mount PleasantFERNHILL CLOSETroedyrhiwCott10aGlantaffYouthCentreTroedyrhiwHousePleasant ViewColbridge!IscoedWaysideHENRY RICHARD STBrynhyfrydHAV EN CLA 4 054Afon Taɵf High SchoolVillas31 32!Pumping Station!Pipe LineFBAfon TaɵfHigh SchoolMelroseCottagesBryn hyfryd Villas143.9mHENRY RICHARD STREET17 22 28TrackEl Sub StaPondPath (um)DrainIssuesCraig y PwllPath (um)Path (um)IssuesSwimming Pool(disused)MP 21.5SpringPARK PLA CE36 33135.9mPathBryncoedCottagesBeechGroveSinks149.4mFair View159.1mTre vethickCraig yr AfonPavilion149.7mTroedyrhiw PumpingWellEdwardStephensTerraceStationSinks187.1mAfon Taf HighSchoolPath (um)207.9mHockey PitchPath218.5mTrackS GantryIssuesHavon Close ShelteredAccommodationDrainRiver Taff (Afon Taf)DrainSinksPath (um)235.6mTramway (disused)Level(disused)256.6mTaff Trail (Cycle Path)132.3mLevel(disused)PicnicSitePath (um)King'sHouseDrain281.3mSLDismantled RailwayIssuesYnysygoredCottages165.5mETLEl PsTBFWFFSinksCRFFDrainTk B CDdefED BdyUndFFDefCBUndFFLevel(disused)CartrefCSRHPlantation CottagesRussell Villa'sBythynnod Y BlanhigfaSt TydfilFilau Russell161.5m128.9mUndB 4285296.3mTrackDismantled RailwayYnys ygore dFarmYnysygored150.3mTaff Trail (Cycle Path)OAKFIELD STRE ETAllotment GardensSTRYD CAE DERWPoliceHousesPANTGLAS FAWR135.6mTCBShelterPlaygroundMTCBA BLUE SQUARE X307Y201Fig. 6April 2011NTSThis map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.¯129.5mPavilionWeirWeirPondA 4054149.0mLevel(disused)Shaft(dis)282.5mPreliminary Assessment Report - MTCBC - Final2503/06/2011

AREAS FLOODED DURINGDECEMBER 1979 FLOODFig. 7April 2011NTSThis map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.¯Preliminary Assessment Report - MTCBC - Final2603/06/2011

Key:> 0.3m> 0.1mMTCBC FLOOD MAP FORSURFACE WATER 1 IN 200Fig. 8 NTSApril 2011This map is based upon Ordnance Survey material with thepermission of Ordnance Survey on behalf of the Controller ofHer Majesty's Stationery Office. Crown Copyright.Merthyr Tydfil County Borough Council. Licence 100025302. 2011.¯Preliminary Assessment Report - MTCBC - Final2703/06/2011

Grid ReferenceHuman healthconsequences -residentialpropertiesHuman healthconsequences -Number of people(2.34 multiplier)Property countmethodIndication Flood Risk Area - Information Provided by the Environment AgencyOther humanhealthconsequences -Number ofcritical servicesfloodedEconomicconsequences -number of nonresidentialpropertiesfloodedProperty countmethodSO0592205878 3022 7071 Detailed GIS 25 806 Detailed GISAreas added to Indicative Flood Risk Area by MTCBCAreas added by making square X304Y207 into a BluesquareX303Y209 0 0 Estimated from map 1 0 Estimated from mapX302Y208 1 2 Estimated from map 0 0 Estimated from mapX302Y207 9 21 Estimated from map 0 0 Estimated from mapX302Y206 17 40 Estimated from map 0 0 Estimated from mapX302Y205 0 0 Estimated from map 0 0 Estimated from mapAdditional Count 27 63 1 0Areas added by making square X307Y201 into a BluesquareX308Y203 0 0 Estimated from map 0 0 Estimated from mapX308Y202 0 0 Estimated from map 0 0 Estimated from mapX308Y201 21 49 Estimated from map 0 0 Estimated from mapX308Y200 0 0 Estimated from map 0 0 Estimated from mapX307Y199 152 356 Detailed GIS 0 6 Detailed GISX306Y200 12 28 Estimated from map 0 0 Estimated from mapX305Y200 0 0 Estimated from map 0 0 Estimated from mapAdditional Count 185 433 0 6EA Blue Square added to Flood RiskAreaX307Y199 152 356 Detailed GIS 0 6 Detailed GISTOTALS FORFLOOD RISKAREA3386 7923 26 818Appendix 1 - Information for Reporting on Flood Risk Area EAW and MTCBC