Draft Hayling Island Coastal Management Strategy Oct 2022

AEP(AnnualExceedanceProbability)

Thechanceorprobabilitythatafloodeventofacertainscalewilloccurata specifiedlocationinanygivenyear.

Baseline

Definesanexistingcondition/situation(usuallyDoNothing)againstwhichoptions orscenariosarecompared.

Bi-modalwaves

Abimodalseastateoccurswhenbothswellwaves(lowerinheightbuthavea longerwaveperiod)andlocallygeneratedstormwaves(highwaveheightsbut shorterwaveperiod)arepresent.Theyresultinaveryenergeticwavespectrum thatcanbeverydamagingtothecoastline.Formoreinformationonhowthese wavesimpactHaylingIslandvisitBimodalSummary—CoastalPartners.

HTL(HoldtheLine)

Apolicywithanoverarchingintenttobuildormaintaincoastaldefencessothat thepositionoftheshorelineremainswhereitcurrentlyis.

Leachate

Aliquidthatabsorbscontaminantsfromthesoilasitpassesthrough.Leachateis relevanttocontaminatedlandstudiesandcantransportcontaminatedmaterials (i.e.heavymetals)totheshoreline.

ManagedRealignment(MR)

Allowingtheshorelinetomovenaturally,butmanagingtheprocesstodirectitin certainareas.Thisisusuallydoneinlow-lyingareas,butmayoccasionallyapply tocliffs.

NoActiveIntervention(NAI)orDoNothing

Noplannedinvestmentindefendingagainstfloodingorerosion,whetherornot acoastaldefencehasexistedpreviously.

OptionDevelopmentUnit(ODU)

Asectionofthecoastlineinwhichlocalscaleoptionstomanagefloodand erosionriskaredeveloped.

PropertyLevelResilience(PLR)

Floodmitigationmeasuresappliedtoindividualpropertiesthatreducetheriskof floodingonapropertylevel(i.e.doorflooddefendersetc).

Residuallife

Thetimeleft(typicallyinyears)thatadefencestructurehasbeforeitcomesto theendofitsservicelife.Theresiduallifeisestimatedfromadefencecondition surveyandassumesthatnomaintenanceworkswillbecarriedoutinthefuture.

Scheme

Ameasure,orcombinationofmeasuresundertakentoincreasethelevelof protectionagainstfloodinganderosiontoalocalarea(i.e.anewfloodwall structure).

SMP(ShorelineManagementPlan)

Ahigh-levelnon-statutoryplanningdocumentwhichprovidesabroadscale assessmentoftheriskassociatedwithcoastalfloodinganderosionandpresents thealong-termpolicyframeworktoreducetheseriskstopeopleandthe developed,historicandnaturalenvironmentinasustainablemanner.

StandardofProtection(SoP)

Theleveloffloodriskthatacoastaldefencestructureisdesignedtoprotect against.Thelikelihoodthatacertainleveloffloodingwilloccurisdescribedas the'chance'thatalocationwillfloodinanyoneyear.Thisriskcanbeexpressed asa1in100(1%)chanceoffloodinginanyoneyear,ora1in200(0.5%)chance, andsoon.Inanyoneyearalarge(0.5%)floodeventhaslesschanceof happeningthanasmaller1%or2%floodevent.

Sustain

Thisisatermwhichreferstooptionsthatkeeppacewithchange(e.g.sealevel rise).Thisisachievedbyraisingorupgradingdefencesinthefuture.

StrategicCoastalManagementApproaches

•AcceptingtheTide:Allowingthecoasttoevolvenaturally,noactive management.

•ReducingtheimpactsoftheTide:Controllingnaturalprocesseswithhard defences,toprotectpropertiesbehindthedefence.

•WorkingwiththeTide:Workingwithnaturalprocessesandreinstatingnatural defencessuchassaltmarshes.

•AdaptingtotheTide:Adaptingtoachangingenvironment,forexampleby movingdefenceslandwardorrelocatingproperty.

Chapter1: Introduction

CoastalPartnersandEngineeringandEnvironmentalConsultancyAECOMhave developedadraftCoastalManagementStrategyforHaylingIsland(hereafter referredtoasTheStrategy)onbehalfofHavantBoroughCouncil(HBC).

HaylingIslandhasapopulationofmorethan17,000andislocatedonthesouth HampshirecoastwithintheBoroughofHavant.Theislandhasa38kmcoastline, characterisedbybothahighlydynamicwavedominatedopencoastareaand moreshelteredtidallydominatedareaswithintheharbours.Theislandislow lyingwithamixoflanduseincludingrural,agriculturalanddenselypopulated urbanareas.Accessandegressonandofftheislandisviaasoleroadbridge connectiontothemainland(A3023).

TheStrategyareacontainsamixofresidentialandcommercialproperties. Therearelargeareasofopenspaceandsitesofsignificantenvironmental importancearoundmuchofthefrontage.Inadditiontherearehistoricalland marksandhighgradeagriculturalland.Thisdiverseandinterestingcoastal environmentprovidesextensiveaccessandrecreationopportunitiesandis widelyusedforleisurebyasignificantnumberofvisitorseachyear.Hayling Island’sbeachesarepopularwithswimmers,surfers,sailorsandwalkersalike, withtheseafrontstretchingover5kilometres,plustheshorelinesofLangstone andChichesterharbours.BeachlandsisaEuropeanBlueFlagbeach,andisthe maintouristattraction.Withuninterruptedviewsacrossthesea,itispossible toseetheIsleofWight,andtowatchtheferriesastheypassenrouteto continentalEurope.

ManypartsofTheStrategyfrontagearealreadydefended;however,the condition,StandardofProtectionagainstfloodingandexpectedlifeofthese defencesishighlyvariable.Thismeansthatsignificantareasoflandacross HaylingIslandareatriskoffloodingfromlargestormevents.Partsoftheopen coastarepotentiallyatthreatfromcoastalerosion. Inthefuture,withtheincreasedstorminessandrisingsealevelsthatare predictedasaconsequenceofclimatechange,theriskofcoastalfloodingand erosionislikelytoincreasesignificantly.

Justover40%oftheislandsflooddefencesareprivatelymaintainedwithan assortmentofdefencestructuretypes.Theremainderaremaintainedbythe EnvironmentAgency,HBCandHampshireCountyCouncil(HCC).HBCalso undertakebeachmanagementalongtheopencoastsectionatEastokewith nourishmentandrecyclingactivities.Manyoftheseassetsarecomingtothe endoftheirresiduallife,requiringsignificantinvestmenttowithstandthe impactsofclimatechangeinthefuture.

Withalloftheinteractingandcompetingpressuresonthecoastlinethe primaryobjectiveofTheStrategyistoprovidealongtermplantoreducethe riskofcoastalfloodinganderosiontopeople,thedevelopedandnatural environmentforthenext100years.

Itachievesthisbyidentifyingasuiteofleadingoptionstomanageandreduce theserisksinacosteffective,holisticandsustainablemanner.

ThedraftStrategyisnowinathreemonthperiodofconsultation(October, NovemberandDecember2022).Duringthistimekeystakeholdersandthe publicareinvitedtoattendaseriesofexhibitionstoreviewandprovide feedbackonthedraftStrategyoptions. Pleasevisithttps://coastalpartners.org.uk/project/hayling-island-coastalmanagement-strategy-16/forfurtherdetails.

StrategyObjectives

TheaimoftheHaylingIslandCoastalManagement Strategyisto:

•Developstrategiccoastalmanagementoptionsfor HaylingIslandforthenext100years

•Outlineaprogrammeofinvestmenttoreducethe riskofcoastalfloodinganderosiontopeopleliving ontheisland

•Identifythepotentialfundingsourcesandpartners requiredtodeliverthatinvestmentprogramme andbeopenandhonestaboutwherefundingis likelytobeachallenge

•Incorporateadaptationstrategies,asdefence improvementswillnotbepossibleinalllocations

•Beholistic,yetflexibleforbothpeopleandnature

•Respondtofuturechanges,supportsustainable developmentoftheislandandtakeinto accountpredictedsealevelriseandclimate change

•Makeapartnershipapproachcentral,between HBC,EnvironmentAgency,NaturalEngland, landowners,businessesandlocalcommunities, makingsurelocalneedsandprioritiesareatits core

HaylingIslandFrontage

TheShorelineManagementPlanHierarchy

ShorelineManagementPlans(SMPs)sitatthetopofthehierarchyofplansfor managingcoastalfloodinganderosion.

AShorelineManagementPlan(SMP)isahigh-levelnon-statutoryplanning documentwhichprovidesabroadassessmentoftherisksassociatedwith coastalprocessesandpresentsalong-termpolicyframeworktoreducethese riskstopeopleandthedeveloped,historicandnaturalenvironmentina sustainablemanner.

AnSMPaimstomanageriskbyemployingarangeofmethodswhichreflect bothnationalandlocalpriorities,to:

•Reducethethreatofcoastalfloodinganderosiontopeopleandtheir property;and

•Benefittheenvironment,societyandtheeconomyasfaraspossible,inline withtheGovernment’s‘sustainabledevelopmentprinciples’.

TheStrategyareafallswithintheboundariesoftheNorthSolentSMP(2010). ThisSMPpresentsthehigh-levelpoliciesforfuturemanagementofthe coastline.Thesepolicieswerefinalisedfollowingaperiodofpublicconsultation andwereformallyapprovedbytheEnvironmentAgencyandadoptedby HavantBoroughCouncilin2011.

TheSMPpolicyforthemajorityofthecoastlinealongthenorth,eastandsouth ofHaylingIslandistoHoldtheLineforthecomingcentury.Thesesectionsof coastlineincludethepotentialthreatoferosionandcoastalfloodingtothe mainurbanareas,landimportantforagricultureandaccessto/fromtheisland. Thispolicymeansthatthereisanoverarchingintent,subjecttomoredetailed studiesandfunding,tocontinuetodefendsothatthepositionoftheshoreline remainswhereitiscurrently.

Inordertomaintainkeyhabitatsandenhancethenaturalenvironmentthere arealsoareasinthewestofthefrontagewheretheSMPpolicyistoallow naturalprocesstocontinue(NoActiveIntervention).Thispolicymeansthatthe shorelinewillcontinuetoevolvenaturallyinthefutureandthatnonew defenceswillbebuilt.

TheSMPpoliciesforHaylingIslandareshownoverleaf.Whilsttheseindicatea HoldTheLinepolicyforthemajorityoftheHaylingIslandfrontage,thisdoes notmeanthatthispolicyappliesforthenext100years.TheSMPpoliciesfor thedifferentepochsarefurtherdetailedforthedifferentfrontagesin Chapter5.

TheNorthSolentSMPisavailabletoviewatShorelineManagementPlanShorelineManagementPlan(northsolentsmp.co.uk).

HaylingIslandCoastalManagementStrategy4

Legend

Coastalstrategiessitatthesecondtierinthehierarchyofcoastalmanagement anditistheroleofstrategiestoidentifytheappropriateschemeorrisk mitigationoptionforimplementingtheSMPpolicies.TheStrategyreviewsthe SMPpoliciesinmoredetailtoensurethesehigh-levelpoliciesremain appropriateatthelocalscale. TheStrategyconsidershowfloodanderosionriskislikelytochangeinthefuture inresponsetochangesinclimateanddevelopssustainableandrobustoptionsto managetherisksassociatedwithcoastalfloodinganderosion.Thisapproach ensuresthattechnicallyfeasible,environmentallyacceptableandeconomically viableoptionsarerecommendedtoreducetherisksfromcoastalfloodingand erosiontopeople,theirpropertiesandtheenvironment.Thisalsoensuresthat theoptionsarecompatiblewiththethoseofadjacentareas.

Withoutsuchanapproach,itislikelythatcurrentmanagementapproaches wouldcontinueintheshorttermandfuturecoastaldefenceworkswouldbe managedonan‘ad-hoc’orreactivebasiswhichwouldleadtopoorcost efficiencyandageneralincreaseinthefloodanderosionriskovertime.A Strategyisalsoimportanttodeliveranintegratedapproachtothemanagement ofourcoastline.Holisticwider-levelthinkingbehindStrategydecisionsensures thatthemanagementoptionsimplementedinoneareadonotincreasetheflood anderosionriskinadjacentareas,andthatopportunitiestodeliverwider benefitsarenotmissed.

Theoutputs

HowTheStrategyfitsinthemanagementofcoastalfloodanderosion risk

FollowingaStrategy,avarietyofoutputscanresult,dependingonthelevelof riskandthepreferredoptionsputforward.Todeliverastrategicoptionitmay benecessarytoimplementascheme(e.g.buildnewdefences)toaddress coastalfloodanderosionrisks.Beforeworkshappenontheground,afurther elementofworkiscarriedouttodesigntheschemeanddeliverthebusiness caseforfunding.Wewillworktodevelopbusinesscasestoprogressschemes ifthereisfundingandifitisinthepublicinterest,wherethereisatechnical, environmental,socialandeconomicsolution.

Inotherareas,thefutureactionmayincludemaintenance,beach managementorevento‘DoNothing’ifappropriate.Theremayalsobeactions suchasmonitoring,planningandfurtherstudiesinordertogainevidenceto helpmakerobustmanagementdecisionsinthefuture.Thiscouldincludethe needforadaptationwhichfocussesonadjustingto,andmanaging,theimpacts offloodingandcoastalerosion.

ThisdocumentpresentsthedraftStrategyforpublicconsultationandsetsout therecommendedoptionsformanagingcoastalfloodanderosionriskalong thestudyfrontageforthenext100years.IndevelopingTheStrategy,an understandingofthepresent-dayriskhasbeendevelopedalongwithhowit mightchangeinthefutureandthewaysinwhichwecanmanageandadaptto thesechanges.Specifically,thisdocumentincludes:

Chapter2–Understandingwhatisatrisk

•Asummaryofwhatisatrisknowandinthefuture(definingthebaseline). Includinganassessmentofwhatwouldhappenifwe‘donothing’andhow theriskschangeovertimeasaresultofpredictedclimatechangeandsea levelrise.ThissetsthecontextforwhyweneedTheStrategy.

Chapter3–DevelopingTheStrategy

•Overviewofthestudyarea-KeyFeatures,IssuesandOpportunities.This identifiesthekeyaspectsandcharacteristicsofthestudyareawhichThe Strategyhasconsidered.Thisincludescoastalprocesses,historiccoastal landfill,theenvironment,stakeholderengagementandaspirations,anda summaryoftheexistingdefences.

•Adescriptionoftheoptiondevelopmentandappraisalprocess.Includinga summaryofhowthestrategicoptionsweredevelopedandappraised consideringtheireconomicandenvironmentalsustainability.

Chapter4–Strategyoverview

•AsummaryofTheStrategy–therationalebehinddecisionsanddiscussion ofthekeyprinciples.

•Anoverviewofthekeyeconomic,environmentalandbroaderoutcomesof TheStrategy.

•Howiscoastalfloodanderosionriskmanagementfunded–Thisincludes detailsofhowpartnershipfundingworksforFlooddefenceschemesinthe UKandthelikelihoodoffundingforthepriorityschemesidentifiedinThe Strategy.

•Deliveringmore.Howwehavebeenworkingwithotherorganisationsto tryanddelivermoreforyourcoastline.

Chapters5–DraftStrategyOptions

ThedraftpreferredoptionsbyOptionDevelopmentUnit(ODU).Anarea-byareasummaryofthedraftStrategyoptionsbeingputforwardtoreducefuture coastalfloodanderosionrisk.Includingatimelineoftheshorttermfuture projectactivitiesandindicativemilestones.

Chapter6–Whatnext?

Whatdoweneedfromyou?EngagementandfeedbackfromKeystakeholders andthepublicformsavitalpartofshapingthefinalStrategy.Wewanttohear yourviews.

ThechaptercloseswithasummaryofthefutureprogrammetofinaliseThe Strategy.

Chapter2: WhatisatRiskifweDo Nothing?

Gaininganunderstandingofthefloodanderosionriskalongtheshorelineis imperativeinordertodefineabaselinefordevelopingTheStrategy.Itallows comparisonstobemadebetweenthepotentialstrategyoptionsandisan essentialstepinTheStrategydevelopmentprocess.Thebaselinewas establishedbyconsideringa‘DoNothing’scenario. The‘DoNothing’scenarioisdefinedas:“Wherethereisnofurtherintervention ofanykind,includingnoemergencyresponseorwarningsystem.Wherethere areassetsatpresentorwheremaintenanceactivitiesorotherinterventionsare carriedout,theoptionwillbetowithdrawallactivities,allowingnaturetotake itscourse”.

Inessence,the‘DoNothing’scenariorepresentsahypotheticalsituation wherebyallexistingdefencesareabandonedintermsofmaintenanceor repair,andnoremedialoradditionalprotectionworksarecarriedout.In addition,adaptationtosealevelriseorotherclimatechangeresponsesarenot addressed.

ForthepurposeofTheStrategy,therisksposedbycoastalfloodingand erosionoverthenext100yearshavebeenestablishedusingEnvironment AgencyapprovednumericalfloodmodellingandCoastalPartnerserosion predictions.Itshouldbenotedthatevenwiththeexistingdefencesinplace; futurefloodriskwillincreasesignificantlyduetoclimatechangeandrisingsea levels.

Throughdeterminingthepresentandfuturefloodanderosionrisksundera ‘DoNothing’scenario,theproperties,features,assetsandkeyinfrastructure thatareatriskofdamageoverthenext100yearshavebeenidentifiedand valued,afterwhichtheleadingstrategyoptionstomanagetheseriskswere developed.Theassetsatriskinclude(butarenotlimitedto)servicesasvaried ascropproductionandraisinglivestock,climateregulation,coastalhazards, tourismandrecreation,aestheticvaluesandwildspeciesdiversityand habitats.FloodingatLangstoneBridgewouldaffectaccesstoandfromthe Island,andpopulartrailssuchastheHaylingBillyTrailwouldalsobeunder threat.Areasoflandfillcoulderodeandcauseharmtotheenvironment.

Island,includingtheinfluenceofclimatechange,landfillsiteswhichareactively erodingandopportunitiesforhabitatcreation.Inordertomanageandaddress theseissues,itisconsideredimperativetodevelopanFCERMStrategy.Joinedupstrategicthinkingisrequiredtodevelopacohesive,efficient,longtermplan. TheStrategythereforeoutlinestheforwardprogrammeofworkstomost effectively,holisticallyandsustainablymanagethecoastalfloodanderosion

SeaLevelRiseandIncreasingRisk

Asaconsequenceofclimatechangeandcontinuedwarmingoftheglobal oceans,sealevelsareexpectedtoincreaseinthefuture.Thiswillsignificantly increasetidalfloodandcoastalerosionriskacrossTheStrategyfrontageover thenext100years.

Toconsidersealevelrise,TheStrategyhasincorporatedthelatestsealevelrise projections(UKClimateProjections2018UKClimateProjections(UKCP)-Met Office)intothefloodmodellingtoproduce‘DoNothing’floodscenariosfor 2041,2071and2121.Followingthelatestguidelines,underthe‘medium emissions’sealevelrisescenario,meansealevelsacrossTheStrategyfrontage areexpectedtoincreasebyapproximately1moverthecomingcentury.

Aswellasproperties,therearemanyotherimportantfeaturesandvaluable assetsatrisk.Thisincludesschools,churches,publichouses,nationally importantenvironmentallydesignatedsites,heritageassets,keyservices infrastructure,majorroads,coastalfootpathsandcyclewaysandshingle beaches.Thereisalsoariskoferosiontoformerlandfillsiteswhichcouldpose afurtherthreattohumanhealthandtothequalityoftheharbours.

Whatismeantbyfloodrisk?

Floodriskreferstothepotentialforexperiencingflooding.Thisriskisoften describedbythelikelihoodorchancethatacertainleveloffloodingwilloccur atanygivenlocation.Thisriskcanbeexpressedintermsofanaveragereturn periodinyears.Thisriskcanbeexpressedasa1in100(1%)chanceof floodinginanyoneyear,ora1in200(0.5%)chance,andsoon.

Chanceisalsorelatedtothescaleoftheflooding.Inanyoneyearalarge(1in 200year)floodeventhasstatisticallylesschanceofhappeningthanasmaller 1in50or1in20yrfloodevent.Itisimportanttounderstandthata1in100 chanceoffloodingdoesnotmeanthatafloodwillonlyhappenonceevery 100years.Thechanceremainsthesameeveryyear.Throughoutthis documentthescaleoffloodriskisdescribedintermsoftheaveragereturn periodinyears.

TheStandardofProtection(SoP)offeredbyadefenceisalsodescribedin termsoftheeventthatitisdesignedtopreventfloodingfrom.Forexample,if aschemeprovidesa1in100year(1%annualchance)StandardofProtection itmeansitwillbedesignedtopreventfloodingfromalleventsuptothis magnitude.

MuchofthefrontagealongHaylingIslandisprotectedbyman-madecoastal defences.Theseareoftenfrontedbyinter-tidalmudflats,saltmarshesand beacheswhichworktoreduceerosionriskalongthecoastline.Without theseman-madeandnaturalseadefences,theislandwouldbeunderthreat fromerosion,mostnotablyontheopencoastcomparedwiththeharbours.

SeveralsitesaroundHaylingIslandarealreadyeroding,andmoresitescould becomevulnerableduringthenext100yearsifnoactionistaken.For example,partsoftheHaylingBillytrailmayhavetoberelocateddueto futureerosion.Thereisariskthatformerlandfillsitesalongthecoastline, bothdomesticandindustrial,couldwash-outasaconsequenceofsealevel riseandcoastalerosionwithoutsuitablemanagementorremediation. Erosionalongthewestcoastwouldalsoimpactsiteswhichareimportantfor over-winteringbirds;alongthesoutherncoast,propertiesandbusinesses alongtheseafrontcouldbeaffected.

Whatismeantbyerosionrisk?

ForthepurposesofTheStrategy,propertiesorassetsatriskoferosionare thosewhichcouldpotentiallybelosttotheseathroughshorelineretreat duetotheactionofwaves,currentsortides.Theriskhasbeenestimated assumingnofurtherworksaredonetorepairormaintaindefenceswhich currentlyprovideprotection. Understandingthepotentialerosionriskunderahypothetical‘DoNothing’ scenario’isimportantforcomparingtherelativemeritsofoptionsto maintainorimproveprotection.

Erosiononthewestcoast(ABOVE)andeastcoast(BELOW)ofHaylingIsland

Chapter3: HowtheStrategyhas beendeveloped

Beforestrategicapproachestomanagingfloodanderosionthreatscanbe identifiedandevaluated,itisimportanttounderstandthekeyfeatures,issues andopportunitiesthatexistwithinTheStrategyarea.Inordertoachievethis,a numberofstudiesandactivitieswereundertakenduringtheearlystagesof developingTheStrategy.

Theseincluded:

•Engagementwithkeystakeholders,residentsandthewidercommunity–meaningfulengagementwithlandowners,communitygroups,organisations andindividualstounderstandtheiraspirationsandconcerns,tohelpshape TheStrategy(seeAppendixDformoredetail);

•Sitewalkoversandvisualassetinspections–todeterminethelocation,type andconditionofcoastaldefencesandassets(seeappendixBformoreinfo);

•Astudyofcoastalprocesses–requiredtounderstandwaves,tides, sedimentmovementsandtolookatthelonger-termfloodanderosionrisk toboththeopenandharbourcoastlines(seeappendixAformoredetail);

•Desktopassessmentoflandfillsites–toidentifyareasalongthefrontage whichmayrequiredefendingtopreventthemerodingandharmingthe environment(seeappendixCformoredetail);

•Identificationofimportantenvironmentalandheritagefeaturesaroundthe Island–sothatkeyenvironmentalobjectivesandlegalrequirementsto protecttheenvironmentcanbeaccountedforinTheStrategy(seeappendix G,H,Iformoredetail);

•Identifyingpotentialbroaderoutcomesandopportunities–inorderto captureideasastohowTheStrategycanbefundedaswellasdeliverwider benefitstocommunities(seeappendixJformoredetail).

Asummaryofthefindingsoftheseactivitiesrequiredtounderstandthebaseline forTheStrategyisprovidedinthischapter.

MuchofHaylingIslandhasbeenreclaimedovertheyears,resultinginlow lyinglandwithsignificantareasatriskoftidalflooding.Thisisexacerbated ontheopencoastwhenstormandswellwavescombinetoproducebimodalwaveconditions.

ManyofthefloodeventsexperiencedinthepastonHaylingIslandhave occurredinthesouth-easterncorneroftheislandwherethecoastlineis mostexposedtotheimpactsofwaveconditions.Theshelterednorthern partsoftheislandinsidetheharboursarepronetofloodingfromtidalsurges ratherthanlargewaveaction.Residentialroadsandextensiveareasof grazinglandhavefloodedinthepast.Floodinghasalsohistoricallyoccurred adjacenttotheA3023approachtoLangstoneBridge.Thesituationwillbe exacerbatedinthefuturewithsealevelrise.

Theopencoastisalsomorevulnerabletoerosion,duetowaveaction.

TheHaylingIslandcoastlinethatsitswithinChichesterandLangstone

Harboursiscomprisedofmostlymudflats,withsomesaltmarsh.Saltmarsh habitathasbeenerodinginbothharbourssincethe1940s,althoughtherate oflosshasslowedsincethemid-1980s.Duetothenarrowharbour entrances,largeswellandwindwavesarenoteasilyabletopropagatealong theentrancechannelsintotheharbours.Therefore,theriskofcoastal damage,floodinganderosionfromwaveattackinsidetheharbourislimited. Fortheharbours,thegreatestriskisfromextremewaterlevels,ratherthan fromwaveaction.

TheopenbeachalongthesouthcoastofHaylingIslandoffersavery differentsituation.Ithasalonghistoryofhighenergywaveaction,which resultsinsignificantbeachdrawdown,cutbackandlossofmaterial.

HaylingIslandisunusualtootherlocationsinthatitsbeachesaresusceptible tobi-modalwaveconditions,whenlongperiodswellwavesrefractaround theIsleofWight,coincidingwithlocalstormconditions.Theyresultinvery energeticwaveconditionsthatcanbeverydamagingtothecoastline.

TheStrategyrecognisestheimpactsofbi-modalwavesinrelationtofuture management,butmoredetailedresearchonbi-modalwaveswillneedtobe undertakentoinformthedesignofanynewdefencesalongHayling'scoast.

Inthecoastalzonethepresenceoflandfillisariskbecauseerosionoftheshoreline,or flooding,canreleaselandfillintotheenvironmentthroughexposureandleaching.Ifnot dealtwithadequately,thismaterialcanposeathreattotheenvironment.

ThereareeightformercoastallandfillsitesonHaylingIsland.Adesktopstudywas undertakeninordertoclassifyeachofthesesitesasbeingeitherhigh,moderateorlowrisk.

Theriskwasbasedontheprobabilityandconsequenceoflandfillbeingreleasedthrough erosionorasaresultoftidalflooding.TwositeswereclassifiedasbeingatHighRisk,fourat ModerateRisk,andtwoatLowRisk.

TheevidencefromthisstudywasconsideredduringthedevelopmentoftheLeading StrategyOptions.Optionstomitigatetheseriskswereidentifiedandconsideredinthe appraisals.

ExamplesoflandfillatsitesaroundHaylingIsland

HaylingIslandissurroundedbydesignatedsites,includingtheChichesterand LangstoneHarboursSpecialProtectionArea(SPA)/RamsarsiteandtheSolent MaritimeSpecialAreaofConservation(SAC).ChichesterHarbourisalso designatedanAreaofOutstandingNaturalBeauty(AONB).Inaddition,Sinah CommonisadesignatedSSSI(SiteofSpecialScientificInterest).HaylingIsland alsosupportsfiveLocalNatureReserves(LNR),includingTheKenchandthe HaylingBillyLNR.ManyoftheseimportantsitesaresituatedalongTheStrategy coastlineandassuchitisessentialtoconsidertheseareaswhendeveloping TheStrategy. Withinmanyoftheseimportantsitesthereareanumberofdifferenthabitats suchassaltmarshesandmudflatswhichsupportawidediversityofwildlife. Theintertidalmudflatsprovideaparticularlyimportantfeedinghabitatfor birds.PartsoftheislandarealsoidentifiedasBrentGooseandWaderfeeding androostingsites. Unfortunately,withpredictedsealevelrise,itisthoughtthatmanyofthe importantintertidalhabitatswillget‘squeezed’againstcoastaldefence structuressuchasseawalls.Thiscandecreasethesizeandhealthofthe intertidalhabitatsandplaceadditionalstressesonthespeciesthatrelyupon them.Tohelpoffsettheseanticipatedlossesinthefuture,itisessentialforThe Strategytoconsiderenvironmentalimprovementoptionsandinvestigate opportunitiestocreatenewareasofhabitat.

ViewsofSolentMaritimeSACandChichesterHarbourSPA,RamsarandSSSI (ABOVE)andKenchLocalNatureReserve(BELOW)

Marine

Terrestrial

TheIslandplayedavitalroleduringWorldWarII,whenitbecameanimportant militarybasewithasignificantroleinthedefenceofPortsmouthandinthe build-upto,andexecutionof,theD-DayLandings.Theseactivitieshaveleft theirmarkonthecoastallandscapeofHayling,andpillboxes,gunsitesand memorialscanstillbeseentoday.

HaylingIslandisoftenconsideredasoneoftheUK’slasttraditionalseaside resorts.ThelistedRoyalHotelbuiltin1825,alongwithanearbyBathHouse andbathingmachinesattractedwealthyholidaymakerstotheIsland.By1909, beachhutsandbathingtentswereestablishedalongtheHaylingIslandbeach. TheHaylingBillyLinewasanimportantconnection,bringingtouriststothe island.Asaresult,holidaycampsflourishedduringthe1950s.

HaylingIslandoffersarichcultural,historicandenvironmentallegacyasa leisuredestinationwhosegenesisasapre-Victorianexclusivehealthresort evolvedintomasstourismandthedevelopmentoftheholidaycamps.This formedthefoundationofawater-sportsoffer,basedaroundbeingthe worldwidehomeofwindsurfing,followinglocalresidentPeterChilvers’ inventionofthefirstwindsurfboardin1958.Haylingisideallysituatedfora varietyofwatersports,duetoitbeingshelteredbytheIsleofWight.Such sportsincludesailing,windsurfing,powerboating,jetskiing,paddleboarding, kitesurfingandkayaking.

Apillbox,alegacyofthe Island’sinvolvementinWorld WarII.

KitesurfingandWindsurfing–twoofthemanywaterbasedactivitiesonoffer onHaylingIsland’sbeaches

ManyindividualsandorganisationshaveakeyinterestorstakeintheHayling Islandcoastlineformanydifferentreasons.Eachstakeholderisthereforelikely tohaveauniqueviewonitsuse,developmentandfutureprotection.Assuch stakeholderengagementisfundamentalandcanbeasourceofindispensable informationwhichcanbeusedtodefinecoastalissuesandobjectives,steer Strategydevelopmentandachieveconsensusonthefuturemanagementofthe coastline.

Strategydevelopmentsetoutandimplementedaclearmethodologyfor engagingwithlocalcommunities,businessesandpublicbodieswithavested interestintheHaylingIslandcoastline.Thisapproachensuresthatthosewho mayaffect,orareinfluencedbythedecisionsofTheStrategyareactively involvedandinformedattherighttime.

TheaimsofTheStrategyengagementprocesswere:

•toraiseanawarenessandunderstandingofcoastalfloodanderosionrisk nowandintothefuturewithclimatechange

•toidentifythechallengesandconstraints

•toidentifybroaderoutcomeopportunities

•todevelopcommunityinvolvementinthedecision-makingprocessfor managingourcoastline

•tolistentotheircommentsandconcerns.

Stakeholderandpublicengagementhasinformedthecoastalmanagement optionsbearinginmindwhatistechnicallyfeasible,publiclyacceptable, economicallyviableandenvironmentallyacceptable. Atthelaunchoftheproject,apublicsurveywasinitiatedtoseekthe community’sviewsoncoastalmanagementofHaylingIsland.Respondents wereaskedabouttheirconcerns,whatisimportanttothemwhenusingthe coastlineandtheiraspirationsfortheisland.

Theresultsofthesurveyhelpedusunderstandthecommunitiesviewson coastalfloodanderosionriskontheisland,wherethemainareasofconcern wereandwhatwidercoastalopportunitiespeoplewouldliketosee.

FourvirtualsessionswereheldduringdevelopmentofTheStrategy,withthe projects'KeyStakeholderGroup,madeupofrepresentativesofthelocal community,including;localbusinesses,landownersandcommunitygroups.

Thefirstsessionprovidedanintroductiontotheproject,opportunitytomeet theteamandtofindoutwhyaStrategyisneededandwhatisinvolved.

Thenexttwovirtualworkshopsessionshelpeddetermineaspirationsand opportunitiesrelatingtoHaylingIsland’scoastline.

ThefinalvirtualsessionprovidedanopportunitytopreviewthedraftStrategy andaskquestionsbeforethestartofpublicconsultationinOctober2022.

Theprojectteamhavealsoheldanumberofvirtualandinpersonmeetings withlandownersalongHayling'scoastlinetounderstandhowtheyusetheir sectionofcoast,andestablishtheirshortandlongtermaspirationsfortheir frontages.

Throughpresentations,questionandanswersessionsandothervirtual meetings,TheStrategyteamhaslearntahugeamountabouthowpeoplewish toseetheshorelineevolve.Alloftherelevantfeedbackreceivedtodatehas beenusedtoinformthedevelopmentofTheStrategytoensurethatit accountsfor,andcaptureskeystakeholderinputandideas.

TohelpestablishthebaselinefloodanderosionrisksalongTheStrategy frontageitwasnecessarytoidentifytheconditionoftheexistingdefencesand howlongtheyarelikelytolastwithoutmaintenance.Thiswasdoneby undertakingawalkoveroftheentireStrategyshorelineandvisuallyassessing defenceconditioninlinewiththeEnvironmentAgency'sassessmentmanual.

Thereisawiderangeofdifferentdefencetypes,fromearthembankmentson muchoftheeastandwestcoasts,toseawallsandrevetmentsalongthemore exposedopencoastwhichprotectagainsterosionandwaveovertopping.In addition,theopencoastisaffordedprotectionbythebeacheswhichactasa barriertothewaves,however,theyrequireregularmanagementtomaintain thebeachlevelsastheyareanintegralpartofthedefencesystem.

ApproximatelytwothirdsofthedefencesaroundHaylingIslandareownedand maintainedbyprivatelandowners.

Whoisresponsibleformanagingthecoastline?

CoastalProtectionAuthoritiesandtheEnvironmentAgencyhavepermissive powerstocarryoutworkstoprotectagainstcoastalfloodinganderosion. However,thisisnotalegalobligation.ThismeansHBChasthe'power'tocarry outcoastalprotectionworksbutisnotdutyboundtodosoandwillnotbeliable forthefailuretoexercisethesepowers.

Ingeneral,LocalAuthoritiesandtheEnvironmentAgencywillonlyactwhere thereisawidepublicbenefitand/oranappropriateengineeringsolutionthatis achievable.ThisiswhyHBCarecommittedtothisStrategytounderstandwhat canbedonetoprepareHaylingforamoreresilientfuture.

Landownersareultimatelyresponsibleformaintainingorimprovingtheir owndefences.Thereforewheremaintenanceorupgradeofdefencesis referredtoinTheStrategyitisassumedthatthiswillcontinuetobethe Landownersresponsibility.

Approximately70%ofthedefencesaroundtheislandareestimatedtobeina fair,poororverypoorconditionwithashortresiduallife,orprovidealow standardofprotection.Consequently,thereareanumberofcriticalareas aroundtheIslandwherethedefenceshavefailedorarebeginningtofail,some frontingareasoflandfill.

Duringthe1940s,HaylingIsland becameatouristdestination. Initialdefenceswere constructedinorderto maintainthelineofthebeach. Overtime,naturalretreatand lossofmaterialfromthebeach meantitwasnecessarytobuild moresubstantialdefences,to protectthepropertiesbehind.

1947:construction ofnewseawall, Eastoke

Priorto1985,lowbeachlevelsledtomore runupofseawatertotheseawall. Significantovertoppingbywavesoverthe defencesledtolargefloodingeventsat Eastoke.In1985,510,000m³ofshinglewas placedonthebeachasthefirstcampaign ofbeachmanagementonHayling,atacost ofapproximately£4m.Thisbuiltupthe beachlevelsandreducedtheriskofwave overtoppingandflooding.

1940s

1985:thefirst campaignofbeach management

The1990ssawthestartofannualbeach management,whichwascarriedoutas thepreferredmanagementoption.

1960sand 1970s 1980s 1990s 2000s–PresentDay

The1960sand1970ssawlargewavesovertoptheseawall,and causeextremefloodingandsignificantdamagetoproperties. Upgradedconcretedefenceshadcausedthedrawdownofthe beachinfront,underminingthedefenceandincreasingthe incidenceandseverityofflooding.Significantrepairswere carriedouttotheseawallin1978torepairstormdamage.

1960sand1970s:floodingandpropertydamageinEastoke

Beachmanagementoperationsinvolvingrecyclingaswellas importingmaterialhavecontinued.Thisactivityhelpsmaintain beachlevelswhichreducestheimpactofstormwaves.Some beachovertoppingoccurs,whichisretainedonthepromenade withacontrolledflowtotheroaddrainage.In2013,the EastokePointScheme,involvingtheconstructionofthreerock groynesandrockrevetment,wasimplementedtoaddress beachloweringandincreasedfloodrisk.

PresentDayBeachManagement

£3.3millionwaspreviouslysecuredfromtheEnvironmentAgencyto implementaBeachManagementPlan(BMP)alongtheHaylingIslandfrontage.

TheSouthHaylingBMPidentifiedastrategyfordeliveringthebeach managementapproachalongtheopencoast.

DredgingActivitiesandBeachNourishment

Oneofthemethodsappliedtothebeachmanagementactivitiesisbeach nourishment,whichisthereplacementofsedimentlostfromasectionof beach.Thisisachievedprimarilythroughusingeitherbeachrechargeorbeach recycling.Thiswillhelptorestoreadepletedbeachbacktoacceptablelevels.

Restoredbeachlevelscontributetoreducingtheimpactofstormwaves,which inturnhelptomanageflooding.

Beachrecharge:materialissourcedfromoutsidethenormalbeachsediment systemandintroducedtothesamenearshorezone.

Placementofdredgedmaterial, October2016

Beachrecycling:Materialismovedfromanareaofaccretiontoanareaof erosion,torestoreadepletedbeachbacktoacceptablelevels.

Transportationofmaterial,March2017

Ondefiningthebaseline,andhavinggainedadetailedunderstandingoftheprocesses,featuresandissuesoperatingalongthecoast,the developmentandappraisalofstrategicmanagementoptionswasundertaken.

TheoptiondevelopmentprocessreferstothetasksinvolvedtoselecttheleadingstrategyoptionsalongTheStrategyfrontage.Theprocess followedtheEnvironmentAgency’sNationalFloodandCoastalErosionRiskManagementguidelines.

OptionDevelopmentUnits

Floodanderosionrisks,coastaldefencetypes,landuses,landownershipand issuesandopportunitiesvaryalongTheStrategyfrontage.Foreffectivefloodand erosionriskmanagementoptionstobedevelopeditisimportanttoconsiderand recognisethislocalvariability.Withthisinmind,thefirststageoftheoption developmentprocesswastodividethefrontageintosmall,localsections.These sectionsareknownasOptionDevelopmentUnits(ODUs).

ODU1:LangstoneBridgetoNorthneyFarm(split into3sub-unitsa-c)

ODU2:NorthneyMarina

ODU3:NorthneyFarmtoChichesterRoad

ODU4:ChichesterRoadtoMillRytheJuniorSchool

ODU5:MillRytheJuniorSchooltoSalternsLane (splitinto3sub-unitsa-c)

ODU6:SalternsLanetoWilsonsBoatYard

ODU7:WilsonsBoatYardtoFisheryCreek

ODU8:Eastoke

ODU9:EastokeCornertoInnontheBeach

ODU10:InnontheBeachtoNorthShoreRoad

ODU11:NorthShoreRoad

ODU12:NorthShoreRoadtoNewtown

ODU13:Newtown

ODU14:NewtowntoStoke

ODU15:StoketoLangstoneBridgeCarPark

ODU16:LangstoneBridgeCarParktoLangstone Bridge

CoastalManagementApproaches

Thelonglistofoptionsfallwithinthefollowingstrategicapproaches.

AcceptingtheTide

Allowingthecoasttoevolvenaturally,noactivemanagement

ThisapproachisconsideredasthebaselinefortheHaylingStrategy.It involvesnointerventionormanagement,wherethecoastisallowedto effectivelyevolvenaturally.Beachesandsaltmarshhabitatsareableto movelandwardnaturallyassealevelsrise,erosionisunconstrainedand floodingwillbecomedeeperandmorefrequentovertime. Thiswillnotbeappropriateeverywhere,especiallyinbuiltupareas,butis moreaboutacceptingtheriskofflooding.

ReducingtheimpactsoftheTide

Controllingnaturalprocesseswithharddefences

Thisapproachinvolvesbuildingartificialstructureswhichtrytocontrol naturalprocesses.Theseoften‘hard’defencesaredesignedtoreduce erosionorholdbackthetide. Theycannotprotectagainsteverystormeventualityandsodonotstop floodingcompletely,thereisalwaysstillarisk.Theyareallbuiltwitha designlifeandwillnotbesustainableforever.Overtimeandassealevels rise,beacheswilldisappearandnaturalsaltmarshwillreduceasitis squeezedagainstdefences(knownascoastalsqueeze).

Saltmarshhabitats movelandward

Embankments

Morefrequent floodingBeachesmovelandward

Erosioneventsmorefrequent

Seawalls

MethodsofReducingtheimpactsofthetideinclude:

•Seawalls–asseeninfrontofInnontheBeach,HaylingBillycarparkin thenorthandMenghamRythesailingclub;

•Timberorrockrevetments–asseenatthecoastguardstationandjust southofMenghamRythesailingclub;

•Embankments–asseeninvariouslocationsonboththeeastandwest coastsofHaylingIsland.

Underthisapproach,thelevelofchangeinriskovertimewithdifferent optionsisalsoconsidered,inordertofindthebestsolution.Optionsthat Maintain,SustainorImprovethecurrentlevelofprotectionare considered.

WorkingwiththeTide

Workingwithnaturalprocessesandreinstatingnaturaldefences

Byworkingwithnaturalprocessesratherthanagainstthem,thisapproach takesamoresustainableandnaturalapproachtomanagingthecoast. Methodsofworkingwiththetideinclude:

•Beachmanagement–bymovingmaterialfromareasofaccretiontoareas oferosionandbuildingupthebeachafterstorms.Thisneedstobecarried outfrequently.ThismethodiscurrentlyinusealongHayling’sopen coast.

•Beachordunenourishment–wherenewmaterialisplacedonthebeach, orplantingtostabilisedunes.ThebeachatEastokeisnourishedregularly, usingdredgedmaterialfromaboat.

•Groynes–totrapsedimentandbuildupabeach.Thismethodcanhave negativeeffectsbystarvingotherareasofmaterialcausingerosion elsewhere.TherearerockandtimbergroynesalongHayling’sopencoast.

•Offshorebreakwaters–helpstrapbeachmateriallandwardofthe breakwater.Thismethodishowever,onlyeffectiveforwaveovertopping, notfloodinundation.

•Saltmarshrestoration-reinstatinganaturaldefenceagainstfloodingand erosionbyrestoringsaltmarshhabitats.Thisoptionwillappealmoretothe harbourcoasts.

Saltmarshrestoration

Groynes

Beachmanagement

Offshorebreakwaters

AdaptingtotheTide

Adaptingtoachangingenvironment

Thisapproachfocusesonmanagingchange,tominimisethenegative consequencesoffloodinganderosion,whereadaptationtoachanging environmentoccursbymakingcommunitiesmoreresilienttoclimate change.

Itcaninvolve:

•Makingspacetoallowbeachestorollbacklandwardnaturallyassea levelsrise;

•Adaptingpropertysoitismoreresilienttoflooding;

•Makingmodificationsinsideandoutsidetoreduceimpacts;

•Floodwarningandfloodplans;

•Relocatingpropertyorotherassetssuchascarparks;

•Changinglanduses.

Thisapproachhasthepotentialtoprovidenewopportunitiessuchas creatingnewhabitatswheredefencesaremovedbacktomakespacefor thetide.

StrategicOptions

ToassesstherelativemeritsofdifferentStrategyoptions,thebaselinefloodand erosionriskimpactsassociatedwitha‘DoNothing’approachwerederivedineach ODUforthepresentday,2041,2071and2121.Thisallowedforidentificationof theriskareaswithineachODU,andthetimingofrisksdefined.Thisformeda basisfromwhichtodevelopanumberofpotential‘strategicoptions’forfloodand erosionriskmanagement.Theoptionsconsideredincluded:

•DoNothing(baseline–developedineachODU)

•DoMinimum–e.g.maintenanceandrepairs–leastrequiredtoimplement theSMPpolicy

•Maintain–e.g.continuetoprotectagainsterosion

•Sustain–maintainaminimumstandardofprotection(SoP)byraising defencesovertimetokeeppacewithsealevelrise

•DelaySustain–maximiseexistingdefencesthenraiseSoPofdefencesata laterdate

•ImproveSoP–improveSoPcomparedtopresentday

Relocatingproperty

Beachesmovelandward

Floodwarning,adapting property

Movedefences landward

Foreachstrategicoption,anappropriate‘packageofmeasures’foreachODUwas selected.Each‘package’wasproducedinconjunctionwiththeshortlistofoptions andoutlinedthetypeofcoastaldefencestructureandtimingofworksrequired overthenext100yearstoimplementthestrategicoption.

StrategyDevelopment

Technicalconsiderations

AprimaryconsiderationinthedevelopmentofaStrategyistoknowwhatoptionsbeingrecommendedaretechnicallyviable.Thereislittlepointinundertaking detailedeconomicandenvironmentalappraisals,orputtingtheoptionforward,iftheoptioninquestioncannotreasonablybeimplementedontheground. Technicalconsiderationsincludeaspectssuchasthedefencetypeinquestion,timingofworks,spaceandheightrequirements,allinthecontextofthelocation andpresentconditionofthesiteinquestion.Forexample,foracurrentlyundefended,openspacelocation,therearefewtechnicalissuesandarangeofoptions arelikelytobetechnicallyviable(e.g.revetments,seawalls,landraising,floodwallsearthbundsetc.).However,foramoreconstrainedsite,suchasadenseurban environmentwherespacemaybeverylimited,significanttechnicalchallengesmaybepresentformanyoptions(e.g.landraisingorearthbundswhichrequires space)andmaylimittechnicallyfeasibleoptionstothosesuchasafloodwallwhichrequireasmallerfootprinttoimplement.

Socialaspects

TwoonlineworkshopswereheldinNovember2020withkeystakeholders representingorganisations,communitygroupsandlandownersonHayling Island,focussingonunderstandingandcapturingaspirations,ideasand opportunitiesforHayling’scoastalandharbourfrontages,todayandinthe future. Theseresultshelpedustounderstandwhatisimportanttothosethatlive onandvisitHaylingIsland.Theideas,suggestionsandaspirations identified,directlyinformedthedevelopmentofthestrategicoptions alongsidewideropportunitieswhichcouldpotentiallybedelivered alongsidefloodanderosionriskmanagementschemesinthefuture.The optionappraisalprocessaccountedfortheseaspirationsandthereisan intentthatthepreferredoptionsbeingputforwardshouldsupportand facilitatethesewherepossible.

Environmentalaspects

Thekeyenvironmentalconsiderationsandobjectiveshelpedshapethestrategy

options.ThiswasachievedthroughaStrategicEnvironmentalAssessment(SEA) whichwasundertakenasanintegralpartoftheoptionappraisalprocess.An SEAScopingreportwasconsultedonduringtheearlypartoftheproject,and thekeyenvironmentalobjectivesfortheprojectwereconfirmedandthese wererelatedtothefollowingcategories:

EconomicAppraisal

Theeconomicassessmentformedanimportantpartoftheselectionofthe leadingstrategyoptions.Althoughtheleadingoptiondoesnotnecessarilyhave todeliverthemostcosteffectiveoption,becausetherearemanyother determiningfactors(e.g.socialandenvironmentaldrivers),itishowever importanttomakesurethepreferredoptionmakeseconomicsense(i.e.the benefitsofdoingsomethingoutweighthecosts).

Thestrategyoptionsweresubjecttoeconomictestingduringtheappraisal.The assessmentinvolvedanestimationoftheBenefit:Costratioofeachoption.The costsofanoptionwereestimatedaccordingtothedefencetypes(asindicated bythe‘packageofmeasures’),andthedefencelengthsandheights.Theflood anderosionbenefitsofastrategyoptionweredeterminedbycalculatingthe damagesavoidedcomparedtothebaseline‘DoNothing’scenario.

Theoptionswerethenappraisedinrelationtoeachcategory’sobjectivesand theenvironmentalimpactsoftheoptionsweredetermined.Thisinformation wasthenincludedaspartoftheevidenceforselectingthepreferredoption. Wherepossibleitisintendedthatthepreferredoptionsshouldnotsignificantly detrimenttheachievementoftheenvironmentalobjectives,butiftheydo, suitablemitigationorcompensationmustbeidentifiedinordertoensurethe optionsareenvironmentallyacceptable.

Generallyspeaking,thehighertheBenefit:Costratio,themoreeconomically viablethestrategyoption.TheBenefit:Costratiowasusedasatooltohelp informthedecision,andforStrategypurposesaslongasanoptionhada Benefit:Costratiogreaterthan1(i.e.thebenefitsoutweighthecost)itwas deemedaCostEffectiveOption.Sometimesmorecostlyoptionsprovide additionalbenefits,andiftheserepresentbettervalueoveralessexpensive option(i.e.theadditionaldamagesavoidedoutweighthecosts),thenitmay havebeenpreferabletochoosethismorecostlyoption,knownastheWider ObjectivesOption. Itshouldbenotedthatalthoughmanagementoptionsmaybeeconomically viableforthepurposesofTheStrategy,itdoesnotmeantheywillgoahead; therequiredfundingtopayfortheschemesmuststillbefound.

Chapter4: StrategyOverview

StrategyOverview

Aphasedapproachtomanagementbasedonrisk

TheStrategyoptionsproportionatelyaddressfloodanderosionriskswith worksphasedovertimedependingontherisk-basedtriggers.Assealevelsrise inthefuture,andexistingdefencesreachtheendoftheirusefullife,new coastaldefenceswillberequired.TheStrategyhasrecommendedaphased implementationprogrammeforfutureworks,basedonwhenrisksmaterialise.

TheStrategyrecommendsthatfuturefloodriskmanagementintervention optionssustainaminimum1:75year(1.33%annualchance)standardof protection(SoP).Thisstandardhasbeeneconomicallytestedagainst alternativesanditisdemonstratedthat1:75year(1.33%annualchance) minimumSoPisappropriateandeconomicallysoundatthestrategiclevel. Itshouldalsobenotedthatthisstrategiclevelminimumstandardof protectionwillbereviewedandtestedonalocalscaleinthedevelopmentof specificschemes;thismayresultinhigherstandardsofprotectionbeing deliveredlocally.

Howwillfuturemanagementbepaidfor?

Inrecentyearstherehasbeenachangetothewaycoastaldefencesare funded.Thefundingsystem,referredtoasapaymentforoutcomesapproach, rewardspartnershipfundingofschemesandprovidesmanypositivebenefits withlotsmoreschemesnowbeingbuiltasaresult.

Althoughaverysmallminorityofschemescanstillgainapprovalfor100% publicfunding(GrantinAid),schemeswithanexternalcontributionarelooked onfavourablytoalsoattractpublicmonies.Inaddition,themeritsofschemes arenotjudgedpurelyfinancially,andthewideroutcomesthatascheme deliversarealsoconsidered.

Forexample,ifaschememovespeopleinhighlydeprivedareasoutof significantfloodrisk,thispropelstheschemeuptheladderinthebidforpublic funding. TheStrategyrecommendseconomicallysoundleadingstrategicapproachesto managingfloodanderosionrisk.Althoughsomefutureschemesmaybeableto attractsomepublic(GrantinAid)funding,contributionswillberequiredto makeuptheshortfalltoenableschemestoprogress.Byknowingthepotential futurecostsofworks,mechanismstoinvestigateandsecurefundingcanbe developed.

Suchcontributionscouldcomefrom:

ACommunityInfrastructureLevy–wheredevelopersareeffectivelytaxed andthismoneyisspentoncommunityprojects

Schematicshowingadaptivemanagementwithaphasedinterventionovertimeto maintainaminimumSoP

DeliveringMore–broaderoutcomesandcontributions

TheStrategyprimarilypresentstheleadingstrategicapproachesformanaging therisksposedbycoastalfloodinganderosion.However,indoingthis,there arealsomanyotheropportunitiesforTheStrategytoprotect,supportand facilitatewiderbenefits.ThisisakeyobjectiveofTheStrategy. Forexample,anewcoastaldefencetoprotectanareafromfloodingcanbeas simpleasaseawall.Whilstsuchadefencewillserveitspurpose,withsome joinedupthinkingtheremaybeopportunitiestobuildmaintenancefree passivedefencessuchasraisinglandthroughredevelopment.Suchascheme couldprovidemultiplebenefitsandnotjustaflooddefence.Thiscouldinclude regeneration,reducevisualimpact,improveaccesstothecoast,reducefuture maintenancecostsandreduceriskofdefencesbreaching.Apartnership approachsuchasthiscouldalsohelpfunddefencesandensurethattheyare approvedandbuiltmoreefficiently. Inordertoseekthedeliveryofthesemultiplebenefitsoffuturedefence schemes,TheStrategyhasidentified,signpostedandbegunexploringthe opportunities.

OutdoorGymlocatedatEastoke,HaylingIsland

Adaptation

Thedraftleadingstrategyoptionsprovidetherecommendedpathwaysfor managingfloodingandcoastalerosiononHaylingIslandoverthenext100 years.However,theimplementationoftheseoptionsisdependentonfunding availability.Withoutthenecessaryfunding,itmaynotbepossibletoconstruct/ maintainthedefences/measuresrecommendedbytheoptions.Therealityis thatwewillneedtolooktoadaptationasarealisticresponsetocoastalriskson theislandnowandintothefuture.

‘...anticipatingappropriateactiontoprevent

NationalFCERMStrategy2020

CoastaladaptationshouldbeconsideredinALLLOCATIONSalongsidethe leadingstrategicoptionspresentedinTheStrategy.Weneedtoexplore methodstoadjusttotherealityofpresentandfuturecoastalfloodingand erosionrisk. Adaptationfocussesonadjustingto,andmanaging,theimpactsoffloodingand coastalerosion,asopposedtotheotherstrategicoptionswhichaimtomitigate theimpactsthroughphysicalfloodprotectionmeasures.

CoastalAdaptation

Chapter5: DraftStrategyLeading Options

DraftStrategyLeadingOptions

ThefollowingpagesintroducethedraftStrategyleadingoptions.EachODUhasa roadmap,illustratingaCostEffectiveoptionandaWiderObjectivesoptionasa resultoftheassessmentsundertaken,describedinChapter3.

ForeachODU,anoverall'LeadingOption'hasbeenselectedastheoptionwhich scoredthehighestintheappraisal.ForthemajorityofODUstheLeadingoption willbeeitherthe'CostEffectiveOption'ORthe'WiderObjectivesOption,butin someODUs,theCostEffectiveOptionandtheWiderOpportunitiesOptionsare thesame,astheyhaveequalscores.

£CostEffective Option

Wider Objectives

Option

Thisistheoptionwhichprovides

bestvaluefortaxpayers’money inlinewithgovernmentpolicy andguidance.

Thisoptionmeetsthemost objectives(environmental,social andtechnical)usingascored multi-criteriaapproach.

TheroadmapforeachODUpresentsavisualrepresentationofthestrategy option(s)andthekeydescribingeachofthesymbolsispresentedhere.The pathwayapproachshowswhatcouldbepossibleoverthenext100yrs.Butitalso allowsustomovetoalternativepathwaysinthefuture. Forexample,ifpublicfundingruleschangeinthefuture,itmaymean,where thereisnoeconomiccasetodosomethingnow,theremaybeacaseinthe futuretoprogressworks.Oralandownermaydecidetoinvestintheirown privatedefenceswherethereisnonationaleconomiccasetodoso.

DoNothing

Nofurtherinvestmentinexistingcoastaldefences. Defenceswouldbeallowedtofailovertimeandnatural processestocontinue.

Maintenance

Maximisethelifeofexistingcoastaldefencesatcurrent heightthroughpatchandrepairandscheduled maintenance.

CapitalWorks

Constructionofnewcoastaldefences/refurbishment ofexistingcoastaldefences.

Sustaining/ImprovingDefences

Sustaining/Improvingexistingcoastaldefencesby raisingtheheightorconstructingadditionallengthsover time,tokeeppacewithsealevelriseandincreasedrisk.

Set-backdefences

Constructionofasetbackdefencetoreduceriskto assets,alongsideopportunitiesforintertidalhabitat creation.

Adaptation

Adaptingtotheimpactsofcoastalfloodinganderosion. Thiscouldincludeanumberofofdifferentmeasures, suchaspropertyfloodresilience,earlywarningsystems, relocationofassetsandriskinformedlandplanning.

OverviewandKeyDrivers

ODU1islocatedbetweenLangstoneBridgetoNorthneyFarm.ODU1isdivided intothreesub-unitswhichareseparatedbyODU2.

WhilethereisasignificantriskoftidalfloodingacrosstheODU1frontage,thereis

TidalFloodRiskMaps

Hotel.ThereisahistoriccoastallandfillsiteatthefarextentoftheunitinODU1c.

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

FurtherdetailsonthekeydriversforODU1areshowninthetablebelow,along

HoldTheLine

ODU1a:10-15years

ODU1b:10–20years

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

Adaptingtothetide

Makespacefornaturebyconstructingnewdefences furtherinland,toberaisedinthefuturetokeeppace withSeaLevelRise

Reducingtheimpactsofthetide

INTENT:MaintainviabilityofNorthneyRdandtheA3023 intothefutureassealevelrise.

raiseovertimetokeeppacewithsealevelrise.

Adaptingtothetide

INTENT:Maintainfloodprotectiontopropertieswhile makingspacefornaturebycreatingamoresustainable defencealignmentintothefuture.

appropriate,maintainandraiseovertimetokeeppace withsealevelrise.

Reducingtheimpactsofthetide

INTENT:Stoplandfillerodingintotheharbourintothe futureassealevelsrise.

alignment,maintainandraiseovertimetokeeppace withsealevelrise.

OverviewandKeyDrivers

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

OverviewandKeyDrivers

TidalFloodRiskMaps

Map1:Presentdaymodelled extentoftidalflooding,assuming nodefences(1in200Year,0.5% AEP).

Map2:Modelledextentoftidal floodingin100yearstimewith anallowanceforsealevelrise, assumingnodefences(1in200 Year,0.5%AEP).

OverviewandKeyDrivers

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding,

Map2:Modelledextentoftidalfloodingin100years

defences(1in200Year,0.5%AEP).

ODU5islocatedbetweenMillRytheJuniorSchooltoSalternsLane.ODU5is dividedintothreesub-units. ODU5astretchesfromMillRytheJuniorSchoolintheWesttofarmlandintheEast andcomprisesagriculturallandandtheMillRytheHolidayVillage.Theriskisfrom tidalflooding,wherethefloodextentreachestoMillRythevillage.ODU5bCovers privatefarmlandandTournerburyGolfCourse.Theriskisfromtidalflooding.ODU 5cstretchesfromTournerburyWoodsEstatetoSalternsLaneandincludes TournerburyWoodsEstate,andadhocresidentialandcommercialproperties. Floodanderosionriskislow. FurtherdetailsonthekeydriversforODU5areshowninthetablebelow,along withtidalfloodriskmap.ThedraftStrategyroadmapisshownoverleaf.

TidalFloodRiskMaps

Map1:Presentday modelledextentoftidal flooding,assumingno defences(1in200Year, 0.5%AEP).

Map2:Modelledextent oftidalfloodingin100 yearstimewithan allowanceforsealevel rise,assumingno defences(1in200Year, 0.5%AEP).

Reducingtheimpactsofthetide

Reducingtheimpactsofthetide

Adaptingtothetide

Reducingtheimpactsofthetide

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

OverviewandKeyDrivers

TidalFloodRiskMaps

Map1:Presentday modelledextentoftidal flooding,assumingno defences(1in200Year,0.5% AEP).

casetodosomethinghere.

Map2:Modelledextentof tidalfloodingin100years timewithanallowancefor sealevelrise,assumingno defences(1in200Year,0.5% AEP).

OverviewandKeyDrivers

ODU8includestheEastokepeninsula,whichhasbeensplitintotwosections. Thenorthernfrontageincludesamixofresidentialproperties,holidayparks,a sailingclub,marinaandtheRNLIlifeboatstationattheneckofthespit.Thereisa riskoftidalfloodingfromtheharbouralongthisnorthernfrontage.Thereisan economiccasetodosomething.Thesouthernfrontageisprimarilyresidential,but alsoincludesapromenadeandtheSandyPointnaturereserveattheeastofthe frontage.Therisksherearepredominantlyfromwaveovertoppingandcoastal erosion.Thebeachitselfisanavitalcomponentofthecoastaldefence.Thereisan economiccasetodosomething.

FurtherdetailsonthekeydriversforODU8areshowninthetablebelow,along withtidalfloodriskmap.ThedraftStrategyroadmapisshownoverleaf.

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

Map2:Modelledextentoftidalfloodingin100years

defences(1in200Year,0.5%AEP).

IssuesandOpportunities

Reducingtheimpactsofthetide

Constructionofnewdefences,toberaisedinthefuture tokeeppacewithSeaLevelRise.includinga combinationofcrestraising,floodwallsandsetback floodwallsacrossthefrontage.Replacementofall groyneswithnewrockgroynes,andcontinuedbeach nourishmentandbeachrecyclingtoprevent undermining.

Reducingtheimpactsofthetide

INTENT:Maintainahealthybeachalongsidefloodand erosionprotectiontoresidents,communityand businessesatEastoke.

NORTH

HOW:Constructnewdefences(floodwallsandsetback floodwalls),maintainandraiseovertimetokeeppace withsealevelrise.

SOUTH

HOW:Beachmanagementalongsidenewrockgroynes andconstructnewdefences,maintainandraiseover timetokeeppacewithsealevelrise.

OverviewandKeyDrivers

ODU9stretchesalongtheopencoastbetweenEastokeCornerandtheInnonthe Beach.

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

recreationareas,andisbackedbyhighconcentrationsofresidential/commercial areas.Therisksherearepredominantlyfromwaveovertoppingandcoastal erosion.Alongsidesomeprivatedefences,thebeachformsthemaindefenceand iscurrentlymaintainedbyHBCthroughbeachnourishmentandbeachrecycling whichtakesplaceatregularintervals.Thereisaveryloweconomiccasetodo anythinghere.

FurtherdetailsonthekeydriversforODU9areshowninthetablebelow,along withtidalfloodriskmap.ThedraftStrategyroadmapisshownoverleaf.

SMPPolicy

Map2:Modelledextentoftidalfloodingin100years

defences(1in200Year,0.5%AEP).

Workingwiththetide

Workingwiththetide

OverviewandKeyDrivers

ODU10extendsbetweentheInnontheBeachandtheFerryboatInn,whichhas beensplitintotwosections. ThesouthernfrontageincludesthenaturalduneareaofSinahCommon,golf courses,asailingclubandcarparks.Theriskhereisprimarilyfromwave overtoppingandcoastalerosion,butareasofSinahCommonalsonaturally accrete.Thenorthernfrontageincludesbusinesses,theferrycrossingtoEastney,a boatyard,slipways,FerryRoad,theresidentialcommunityattheKench,theKench naturereserveandaholidaycomplex.Thereisariskoftidalfloodingfromthe harbouralongthisnorthernfrontage.ThecommunityattheKenchprivatelyowns andmaintaintheirowndefencesandareactivelyplanningadapttoclimate changerisksinthefuture.Thereisaveryloweconomiccasetodoanything.

FurtherdetailsonthekeydriversforODU10areshowninthetablebelow,along withtidalfloodriskmap.ThedraftStrategyroadmapisshownoverleaf.

SMPPolicy

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

Map2:Modelledextentoftidalfloodingin100yearstime withanallowanceforsealevelrise,assumingnodefences.

OverviewandKeyDrivers

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

OverviewandKeyDrivers

ODU12extendsfromNorthShoreRoadtoNewtown.

SMPPolicy

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

OverviewandKeyDrivers

ODU13encompassesthecoastlineatNewtown.

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding,

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

OverviewandKeyDrivers

ODU14extendsalongthelargelyundevelopedfrontagefromNewtowntoStoke.

TidalFloodRiskMaps

Map1:Presentdaymodelledextent oftidalflooding,assumingno defences(1in200Year,0.5%AEP).

BillyLinepublicfootpath.Thereareminimalassetsatriskfromfloodinghere,

todoanything.

FurtherdetailsonthekeydriversforODU14areshowninthetablebelow,along

FloodandErosionRisks

Map2:Modelledextentoftidal floodingin100yearstimewithan allowanceforsealevelrise, assumingnodefences(1in200Year, 0.5%AEP).

OverviewandKeyDrivers

TidalFloodRiskMaps

Map1:Presentdaymodelledextentoftidalflooding,assuming nodefences(1in200Year,0.5%AEP).

FurtherdetailsonthekeydriversforODU15areshowninthetablebelow,along

SMPPolicy

HoldTheLine(with

Map2:Modelledextentoftidalfloodingin100yearstimewithan allowanceforsealevelrise,assumingnodefences(1in200Year, 0.5%AEP).

FloodandErosionRisks

OverviewandKeyDrivers

ODU16extendsfromtheLangstoneBridgecarparktotheLangstoneBridge, alongsidetheA3023mainaccessroadforHayling.

TidalFloodRiskMaps

SMPPolicy

HoldTheLine(with

NorthneyorRegulated TidalExchangeatStoke) (short,medium&long

FloodandErosionRisks

Floodcellwhichmergeswithcellstothewestandeast(ODU15andODU1

Map1:Presentdaymodelledextentoftidalflooding, assumingnodefences(1in200Year,0.5%AEP).

IssuesandOpportunities

SafeaccessandegressbetweenHaylingIslandandthemainlandisatriskfrom

Map2:Modelledextentoftidalfloodingin100years timewithanallowanceforsealevelrise,assumingno defences(1in200Year,0.5%AEP).

IndicativeCostsandFunding

Chapter6: WhatHappensNext?

Whatweneedfromyou...

Engagementandfeedbackfromkeystakeholdersandthepublicformsavital partofshapingthefinalStrategy.Wewanttohearyourviews. TheStrategyconsultationperiodrunsforthreemonthsfrom3rdOctober2022 to26thDecember2022.Duringthistimekeystakeholdersandthepublicare invitedtoattendaseriesofexhibitionstoreviewandprovidefeedbackonThe Strategyproposals.Followingthispublicconsultationperiod,thefeedbackwill bereviewed,andTheStrategyupdatedaccordingly.Pleasevisit https://coastalpartners.org.uk/project/hayling-island-coastal-managementstrategy-16/forfurtherdetailsofthepublicexhibitionsandthewaysinwhich youcanprovidefeedbackonTheStrategy.

Followingtheevaluationandincorporationofstakeholderandpublicfeedback TheStrategywillbefinalisedduringthespringof2023.TheStrategyand businesscaseforthepreferredoptionswillthenbeputforwardforapproval bytheEnvironmentAgencyinlatespring2023.FollowingTheStrategy’s approval,itwillthenbeformallyadoptedbyHavantBoroughCouncilandThe Strategyactionplanwillbeimplementedalongwithstartingthe commencementofthepriorityschemesoverthecomingfewyears.

TIMELINE