The Planning System and Flood Risk Management - Offaly County ...

More documents

Recommendations

Info

56Climate changeincreased intensityof summer stormsOverland runoffand muddyflooding due tointensive rainfallPlanning GuidelinesGroundwaterflooding due toraised water tableSurcharged sewercauses basementfloodingUrban creep:increased pavingSewerexceedancefloodingDirect overlandflow and ponding inlow spots (sinks)Floodingthrough thealluvialsBlockage or sewer collapseImpervious paved areaFig. A1: Source, pathways and receptors of FloodingReservoir orcanal breachThe ultimate aim of a FRA is to combine these factors and map or describethe risks on a spatial scale, so that the consequences can then be analysed.FRAs need to consider the situation as it is now and also how it might changein the future. Such consideration should include changes in climate (whichimpact largely on sources), the construction of flood protection or drainageschemes (which modify the pathways) and the introduction of receptors intoareas at risk of flooding.Further Guidance on Flood Risk AssessmentsStandards and methodologies for FRAs, and detailed specifications of workfor undertaking a range of FRAs for use in Ireland (i.e., for each stage of FRAat different scales), are available from the OPW (http://www.opw.ie).Comprehensive guidance is also available from research in the UK throughthe following:• Practice Guide that accompanies the equivalent planning guidance(PPS25)http://www.communities.gov.uk/planningandbuilding/planning/planningpolicyguidance/planningpolicystatements/planningpolicystatements/pps25/);• CIRIA Report C624 “Development and flood risk - guidance for theconstruction industry” (http://www.ciria.org.uk/acatalog/C624.html);and• Defra/Environment Agency Guidance on flood-risk assessment (FD2320)and on flood risks to people (FD2321),http://www.defra.gov.uk/environ/fcd/research/default.htm.
1.4 Scales Used For Flood Risk AssessmentFRAs are required at different scales by different organisations for manydifferent purposes. A hierarchy of assessments is necessary to ensure aproportionate response to the needs of organisations by avoiding the need fordetailed and costly assessments prior to making strategic decisions. Thishierarchy is summarised in Table A1.Table A1: Hierarchy of Flood Risk AssessmentFRA Code Purpose ResponsibilityRegionalflood riskappraisalStrategicflood riskassessmentSite-specificflood riskassessmenRFRASFRAFRARFRAs provide a broadoverview of the source andsignificance of all types offlood risk across a regionand also highlighting areaswhere further moredetailed study will berequired. At this levelthey are an appraisal andnot an assessment.To provide a broad (areawide) assessment of alltypes of flood risk toinform strategic land-useplanning decisions.SFRAs enable the LA toundertake the sequentialapproach, including theJustification Test, allocateappropriate sites fordevelopment and identifyhow flood risk can bereduced as part of theDevelopment Plan processTo assess all types of floodrisk for a newdevelopment. FRAsidentify the sources offlood risk, the effects ofclimate change on this, theimpact of thedevelopment, theeffectiveness of floodmitigation andmanagement measuresand the residual risks thatremain after thosemeasures are put in place.Regional planningbodies inconsultation with theOPW, and LAs.CFRAMs will be animportant and primeinput to theappraisal.LAs in consultationwith the OPW, andemergency services.The Flood riskmanagement planarising from theCFRAM programmewill be used heavilyto inform the SFRA.In its absence localauthorities may needto commissionextensive flood riskassessments, albeit ata strategic level.OPW will provideadvice on thespecifications thatshould be applied.Those proposing thedevelopment inconsultation with theLA and emergencyplanners.57Planning Guidelines
Page 7:
At the site-specific level, develop
Page 10 and 11:
Planning Guidelines
Page 12 and 13:
2regard to the guidelines in the pe
Page 14 and 15:
4Planning GuidelinesReport of the F
Page 16 and 17: 6Chapter 2:Flooding - Key ConceptsP
Page 18 and 19: 82.5 Increase in flooding due to de
Page 20 and 21: 10Flood risk2.13 Understanding floo
Page 22 and 23: 122.21 In undertaking a flood risk
Page 24 and 25: 142.30 Increases in rainfall intens
Page 26 and 27: 16after periods of heavy rainfall.
Page 28 and 29: 18that also meet the objectives of
Page 30 and 31: 20more than 1 in 200). Development
Page 32 and 33: 22Government under Section 28 of th
Page 34 and 35: 24Planning GuidelinesDevelopment in
Page 36 and 37: 26Chapter 4:Flooding and Spatial Pl
Page 38 and 39: 28floodplain. Effective co-ordinati
Page 40 and 41: 30Planning GuidelinesFig. 4: Develo
Page 42 and 43: 32• Include zoning objectives to
Page 44 and 45: 34specific areas, ensuring that flo
Page 46 and 47: 36should use the flood risk informa
Page 48 and 49: 38planning authority to ensure that
Page 50 and 51: 40• these guidelines, and in part
Page 52 and 53: 425.22 Where development proposals
Page 54 and 55: 44Chapter 6:ConclusionPlanning Guid
Page 56 and 57: 46TermsDefinitionPlanning Guideline
Page 64 and 65: 54Appendix A - Screening for andCar
Page 68 and 69: 58Strategic assessments provide the
Page 70 and 71: 60As part of a FRA, information on
Page 72 and 73: 62A successful FRA is characterized
Page 74 and 75: 64• Suggested policies for sustai
Page 76 and 77: 66Planning Guidelines• The impact
Page 78 and 79: 68An additional document on interpr
Page 80 and 81: 70Table A2: The Flood Risk Balance
Page 82 and 83: 72Appendix B - Addressing FloodRisk
Page 84 and 85: 74Figure B2 below illustrates how t
Page 86 and 87: 76drainage processes and removing p
Page 88 and 89: 78• Signing of floodplain areas s
Page 90 and 91: 80flood level. Care must be taken t
Page 92 and 93: 82Appendix C - Frequently AskedQues
Page 94 and 95: 84What does the SFRA not provide?Th
Page 96 and 97: 86pressure in the embankment and ge
Page 98: Printed on recycled paper containin
show all

The Planning System and Flood Risk Management - Offaly County ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?