threat from floodingthreat from floodingthreat from flooding

Resilience and ‘building back better’ • Theaverageamountoftimethatpeople

spendoutoftheirflood-damagedhomesisninemonths.

• Bytakingpracticalstepstoincreasetheresistanceandresilienceofapropertytoflooding,thetimetakentorecoverfromfloodingcanbeshortenedconsiderably.Thevalueofaclaimsubmittedbyinsurerscanbereducedorhome-ownerscanremovetheneedtoclaimatall.

• Butinstallingproperty-levelresilienceandresistancemeasuresisnotyetstandardpracticeinfloodaffectedareas.Reasonsincludeadesireonthepartofhouseholderstogetbackintotheirpropertiesquicklyafterflooding,ratherthanwaitformeasurestobeinstalled,andalackoftrustintheeffectivenessofthemeasures.

• Resistancemeasuresaredesignedtoslowdowntheflowofwaterintoaproperty,buyingvaluabletimetomovefurnitureandpossessions.Measuresinclude:floodbarriers,strengtheneddoorsandwindows,floodalarmsandgardenlandscaping.Resiliencemeasuresareaimedatamelioratingflooddamageoncewaterhaspenetratedtheproperty.Theseincludestainlesssteelkitchens,extensivewallandfloortiling,waterproofgroutandadhesive,removablestaircarpetandquickrelease,removableinternaldoors.

CASE STUDY: Slowing the Flow in Pickering ANaturalFloodManagementschemefromPickering,‘SlowtheFlow’,wasdeclaredasuccessin2016,followinganevaluationbytheEnvironmentAgency.Theschemeconsistedof167‘leaky’damsand187heatherbaledamswithinastream,twotimberbunds(part-concretestructuresaimedatdivertingwaterawayfromthetown),andimprovementstofarmland,woodlandandmoorlandintherivercatchment.40,000treeswereplantedandanupstreamstoragereservoirinstalled.ThecommunityinPickeringwasdirectlyinvolvedinthedesignofthescheme,facilitatedbygeographerProfessorSarahWhatmoreandcolleaguesfromtheUniversityofOxford.

TheEnvironmentAgency’sanalysisconcludedthattheschemepreventedfloodinginPickeringaroundChristmas2015,thatwouldotherwisehaveoccurredtoasmallnumberofresidentialpropertiesandthetown’smuseum.Thefloodpeakwasreducedby15-20%,withhalfofthiseffectattributabletoimprovedcatchmentmanagementandtreeplantingandhalftothefloodstoragereservoir.

The Bonfield ReviewA2016reportsuggestedtheuseofBuildingRegulationstoencouragefloodresilientandresistantconstruction,alongwiththeintroductionofindustrystandardsandcertificationprocessesforfloodproductsandtheirinstallation.

Changes in land useUpsteamchangesinlandusecanaffectdownstreamflooding.Forexample,treefelling,increaseddensitiesoflivestockandthemodificationofriverchannelscanleadtoerosionandincreasedrun-off.Suggestedsolutionshaveincludedtheremovalofleveestoreactivatefloodplains,strategictreeplantingandthereversalofsoildegradationtoincreaseinfiltrationcapacity.

TheGovernmenthasrecognisedfloodingasoneofthemostseriousthreatsfacingtheUnitedKingdom:the2017ClimateChangeRiskAssessmentidentifiedfloodingandcoastalchangeriskstocommunities,

businessesandinfrastructureasthegreatestriskposedtotheUKbyachangingclimate.Landusepracticesandprojectedincreasesinheavyrainfallmeanthatthethreatfromfloodingissevereandincreasing.

Winter floods 2015/16• AnalysisbytheCentreforEcology

andHydrologyshowsthatthewinterfloodingeventof2015/16,causedbystormsDesmond,EvaandFrank,wasoneofthemostsevereandextremehydrologicaleventsofthepast100years.

• December2015wasthewettestDecemberonrecord,andthewettestcalendarmonthsincerecordsbeganin2010.

• Itisestimatedthat16,000propertieswerefloodedinEnglandand20,000moreprotectedfromfloodsbyexistingdefences.

• KPMGhasestimatedtheeconomicimpactofthe2015/16winterfloodsat£5billion-£5.8billion.

sources: figure 1: the winter floods of 2015/2016 in the uk - a review. centre for ecology & hydrology; figure 2: flood risk & management and funding, house of commons library. design + illustration: www.greg-stevenson.co.uk

Natural Flood Management• NaturalFloodManagementisthe

alteration,restorationoruseoflandscapefeaturestoreducefloodrisk.Alteringfeaturesoftenincludes‘soft-engineering’,whichhasbeendefinedasengineeringwithnaturalmaterials,suchassoil.

• Althoughtheevidenceislimited,thereareindicationsthatNaturalFloodManagementhasagreaterroletoplayinsustainablefloodriskmanagementintheUKthanitdoesatpresent.Itcanbeeffectivewhenusedaspartofaportfolioofmeasures,includingplanning,infrastructuredesignandregulation,tailoredtothegeographyofthecatchment.Therearealsowidersocial,environmentalandeconomicbenefitstonaturalfloodmanagement,includingbenefitsforbiodiversity.

• ThesuccessofNaturalFloodManagementdependsonthecatchmentscale,thescaleofthefloodinginvolved,thewillingnessoflandownerstocooperateandtheneedsofthecommunitiesatrisk.

• ThereispresentlyalackofevidencefortheefficacyofNaturalFloodManagementatlargerscalesandaneedtofillthisresearchgap.

Figure 1: November2015–January2016rivercatchmentoutflowsthehighestsincerecordsbeganin1960s

Funding for flood risk managementTheGovernmenthascommitted£3.2billionfornewflooddefences,maintenanceandrepair,upuntil2021.

Figure 2: UKGovernmentspendingonfloodandcoastalerosionriskmanagement2000–2017

CASE STUDY: Cumbria CumbriawastheworsthitareaoftheUK,withwaterlevelsinthemainriversexceedingthehighesteverrecorded.*

12monthsonfromtheaftermathofStormDesmond,oneinfivehouseholdswereyettoreturnhome.

“AcrossCumbria,1,029businesseswerefloodedthatday;ofthese,76percentareoperationalagain,while24percentremainclosed.200roadsorbridgeshaveyettobefullyrepaired,althoughmostareinuseagain.”

*Geographicalarticle:socialimpactsoffloodinginCumbria(“InRecovery–12monthsonfromStormDesmond”byKarenLloyd,Geographical,18January2017)

“It was the speed of it that was so shocking. Between 4pm and 5pm the water was rising at an inch a minute. By 5pm we were up to our chests.” ChrisWhite,Resident,Cumbria

Flooding from sea

Land use changes

Flooding from

rivers

Overloaded sewers

<2000/1 2016/17>

<1960s 2015/16>