ODU7:WilsonsBoatYardtoFisheryCreek
Overview
ODU7islocatedbetweenWilsonsBoatYardandFisheryCreek.Thefrontage comprisesalargeextentofresidentialpropertiesandavarietyofcommercial landuses,includingWilson’sBoatYard,MenghamRytheSailingClubanda numberofholiday/touringparks.
Environment
TheintertidalHarbourareaborderingthisfrontageisenvironmentally designatedasSSSI,Ramsar,SPA,SACand,alongwiththelandwardeastern fringe,fallswithintheChichesterHarbourNationalLandscape.Twoareasof formerlandfillarealsolocatedalongthemorevulnerablesectionoffrontage, whereriskoferosionisprobableinthenearfuture.
Defences
Defencesvaryalongthefrontage.Alongthenorth-easternsectionconcrete revetmentsandquaysareadjacenttotheEnvironmentAgency’sSelsmore andMenghamCoastalDefenceschemewhichconsistsofrockrevetment andwascompletedin2012.Defencesalongthissectionareprivately ownedbutmaintainedbytheEnvironmentAgencyandhaveresiduallives oftypically10to20plusyears.
Tothesouth,thereisashortsectionofrockfilledgabionbasketswhichare ingoodcondition,againprivatelyowned,butmaintainedbythe EnvironmentAgency.However,theremainingfrontageextendingtowards FisheryCreekconsistsofanaturalearthvergewithnoharddefences.The vergeisinpoorcondition,hasashortresiduallifeoflessthan10yearsand isactivelyerodinginplaces.
ShorelineManagementPlanPolicy
HoldtheLineforthenext100years.
WilsonsBoatYard
Risk
Themainriskalongthenorth-eastfrontageisfromtidalflooding.Herethereisacontinuousfloodcellwhere approximately302propertiesareatriskoverthenext100years,withoutdefencesinplace.Alongthesouth-east coastthemainriskisfromerosionwherethereisformercoastallandfillatrisk.
Themapsbelowshowthemodelledextentanddepthsofanextremetidalfloodevent(1in200year,0.5%annual probability),withoutanydefences,todayandin100years,allowingforsealevelrise.
Erosionrisk
Numberofpropertiesatrisk,withnodefences
Tidalfloodrisk
Numberofpropertiesatrisk,withnodefences
£10,888,000 PresentValue
StrategicIntent
Thestrategicintentfortheunitistoreducefloodanderosionrisk topropertiesoverthenext100yearsbutalsopreventformer landfillfromeroding/leachingintotheHarbour.Thiswillrequire constructionofnewdefencesinaphasedapproachovertime.
NextSteps
AFloodandCoastalErosionRiskManagementSchemeforthe frontagehasbeenproposedintheStrategy’sshorttermactionplan. Subjecttosecuringfunding,thiswillstartwithafeasibilitystudyto appraiseappropriatecoastalmanagementoptionsandalignments alongthisfrontage.