coastal protection - core · pacifi c coasts are designated important areas for providing vital...

C O A S T A L P R O T E C T I O N B E S T P R A C T I C E S

Coastal ProtectionB E S T P R A C T I C E S I N T H E P A C I F I C

European Union

B E S T P R A C T I C E S C O A S T A L P R O T E C T I O N

©2015bythePacificCentreforEnvironmentandSustainableDevelopment(PaCE-SD)andTheUniversityoftheSouthPacific,Suva,Fiji.

Thisworkiscopyright.Nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmittedinanyformbyanymeanswhatsoeverwithoutthepriorpermissionofthecopyrightowners.TheUniversityoftheSouthPacificandPaCE-SDacceptnoliabilitywhatsoeverwhetherbyreasonofnegligenceorotherwisearisingfromuseorrelianceonthisreportoranypartofit.

PublishedbyPacificCentreforEnvironmentandSustainableDevelopment(PaCE-SD),Suva

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AllenquiriesrelatedtothisworkshallbeaddressedtoPaCE-SD,TheUniversityoftheSouthPacific,SuvaFiji.

Cover Photos

(Top):AviewofnaturalmangrovestakenfromNavulivatu,Fiji.(BottomLeft):NaturalcoraltakenatFunafuti,Tuvalu.(Middle):Concreteslopewall,SolomonIslands.(BottomRight):Concretewalls infrontofThurstonGarden,Suva.

Unlessotherwisestated,allimagesinthisreportarecopyrightofthePaCE-SD.SpecialthankstothePaCE-SDteamfortheircontributionstotheimagedatabase:AlitiKoroi,AmeTuisavusavu,AntoineDeRamonN’Yeurt,BirthaTogahai,ChristopherWard,HélèneJacotDeCombes,JasonAlonk,JohnWalenenea,LeoneLimalevu,LukePaeniu,MosesAsitarau,PeleniseAlofa,RoseGodana,SarahHemstock,TessaKoppert,VaineWichman,ViliamuIese,WilliamArudovo,TevitaFakaosi.

Citati on

PaeniuL,IeseV,JacotDesCombesH,DeRamonN’YeurtA,KorovulavulaI,KoroiA,SharmaP,HobgoodN,ChungKandDeviA.(2015).CoastalProtection:BestPracticesfromthePacific.PacificCentreforEnvironmentandSustainableDevelopment.(PaCE-SD).TheUniversityoftheSouthPacific,Suva,Fiji.

USP Library Cataloguing-in-Publicati on Data

Coastalprotection:bestpracticesfromthePacific/L.Paeniu...[etal.].--Suva,Fiji:PacificCentreforEnvironmentandSustainableDevelopment,TheUniversityoftheSouthPacific,2015.80p.;30cm.ISBN978-982-01-0936-01.Shoreprotection--Oceania.2.Coastalzonemanagement--Oceania.3.Coastalengineering--Oceania.I.Paeniu,Luke.II.TheUniversityoftheSouthPacific.PacificCentreforEnvironmentandSustainableDevelopment.GC1023.885.C632015333.91716099--dc23

Disclaimer

TheviewsandopinionsexpressedinthisreportarethoseoftheauthorsanddonotnecessarilyreflecttheofficialpositionofTheUniversityoftheSouthPacific,ThePacificCentreforEnvironmentandSustainableDe-velopment,TheEuropeanUnion,andTheUnitedStatesAgencyforInternationalDevelopment.

European Union


B E S T P R A C T I C E S I N T H E P A C I F I C


OnbehalfofPaCE-SD,wewouldliketoacknowledgetheleadershipandvisionofthePaCE-SDDirectorandProfessorinClimateChange,ElisabethHollandforinitiatingthe‘fantasydream’ofcreatingbestpracticereportsoncoastalzoneengineering.ThepublicationofCoastalPro-tection:BestPracticesfromthePacificreportisthefirstinaseriesofsimilarreportstofollow.

ItisequallyimportanttomentionthesupportingroleplayedbytheUnitedStatesAgencyforInternationalDevelopment(USAID)withtheirfundingsupport.

ThankyoualsotothosewhohavecontributedbysharingtheirexperiencesoverthePacificSolutionExchange(PSE)network.(FeaturedinChapter5).

WearedeeplyprivilegedtoacknowledgethesupportprovidedbytheEuropeanUnionGlobalClimateChangeAlliance(EU-GCCA)In-CountryCoordinators(ICCs)inthe15Pacificcountriesfortheirvaluablecontributions.EU-GCCAICCsareAbeAremwa,BettySigrah,BirthaTogahai,CarolEmaurois,JasonAlonk,MosesAsitarau,NaushadYakub,PeleniseAlofa,TamaraGreen-stone,TapulolouTuailemafua,TessaKoppert,TeulealaManuellaMorris,andTevitaFakaosi.Wewouldalso liketoacknowledgethecontributionsof JohnWalenenea,RoseGodana,AmeTuisavusavu,ChristopherWard,SairusiBosenaqaliandSarikaChand.

WealsoacknowledgethecontributionsbyProfessorRandolphThaman,andthankhimforhispositivefeedback.WewouldalsoliketoacknowledgethepioneeringworkdonebythethenSouthPacificIslandsAppliedGeoscienceCommission(SOPAC)oncoastalprotectionthathasservedasabaselineforthisreport.

Lastbutnotleast,thePaCE-SDcoreTaskForcewhoworkedreallyhardtoproducethisreportareacknowledgedwithadmirationandappreciation.TheyareProfElisabethHolland,StephenSmith,SarahHemstock,MorganWairiu,ViliamuIese,HélèneJacotDesCombes,AntoineDeRamonN’Yeurt,AlitiKoroi,PriyaSharma,AshmitaDevi,LukePaeniu,NicholasHobgood,IsoaKorovulavulaandTeddyFong.

Acknowledgement

i


C-CAP CoastalCommunityAdaptationProject

CTI CoralTriangleInitiative

EIA EnvironmentalImpactAssessment

ENSO ElNiñoandSouthernOscillation

ESD EcologicallySustainableDevelopment

ESCAP EconomicandSocialCommissionforAsiaandthePacific

FSM FederatedStatesofMicronesia

GIZ DeutscheGesellschaftfurInternationaleZusammenarbeit

ICZM IntegratedCoastalZoneManagement

IPCC Inter-governmentalPanelofClimateChange

JICA JapanInternationalCooperationAgency

LMMA LocallyManagedMarineArea

MMA MarineManagedArea

MPA MarineProtectedArea

PACC PacificAdaptationtoClimateChange

PaCE-SD PacificCentreforEnvironmentandSustainableDevelopment

PIPA PhoenixIslandProtectedArea

PNG PapuaNewGuinea

PSE PacificSolutionExchange

SOPAC SouthPacificIslandsAppliedGeoscienceCommission

SPC SecretariatofthePacificCommunity

UK-SPEC UnitedKingdom-StandardforProfessionalEngineeringCompetence

UNDP UnitedNationsDevelopmentProgramme

USP TheUniversityoftheSouthPacific

4AR FourthAssessmentReport(IPCC)

Acronyms

ii


IampleasedtopresentanothershiningmilestoneofPaCE-SD’scontinuouseffortsinstrivingforexcellence.ThisBestPracticepublicationisauniquecollaborativeundertaking.Thereportprovidesafoundationtoguidecoastalmanagers,coastalplanners,coastalengineers,decisionmakersanddisastermanagersthroughoutthePacificintheireffortstofindsolutions.Thegoalis todevise ‘noregret’strategiesusingeffective interventionstoprotectthePacificcoasts,ecosystemsandbasicvitalinfrastructure.

Thedocumentisnotintendedtoprovideeasyanswerswiththerightcoastalprotectioninter-ventionsforeverylocation.Everylocationhasitsownuniquechallengesandproblems.Solu-tionsareco-learningopportunitiesandshouldbegeneratedlocallyanddesignedwithlocalinputwithallpossibleoptions.Thisdocumentisonlyaguidetotheoptions.

Iwanttoexpressmyappreciationtothosewhowillinglysharedtheirexpertiseandexperi-ences via the Pacific Solutions Exchange (PSE) network. The report is a truly collaborativeproductworkingacrossprojectsandthePacificIslandstogenerateeffectiveoptionsforthe15PacificIslandcountriesweserve

ItisinterestingtonotethattheexperiencessharedinthisdocumentwereacombinationofthosesharedinthePSEnetworkandthoseprimarilycollectedfromover70Pacificliteratures.ThePacificIslandsregionhasrichsourcesofconstructiveandvitalknowledgeonhowtopro-tectthecoast,andourPacificbasedsolutionsaresomethingtobeproudof.Wehavetriedtobringifnotallbutmostoftheseexperiencesinonesingledocumentforeaseofreference.

Itismyintention,thatthisdocumentcouldbecomealivingdocumentthatwouldbereferredtoandrevisedwhentheneedarises.

IcommendthecoreTaskForceofPaCE-SDforthehardworkanddedicationinproducingthisimportantdocument.Thankyouawesomeshiningstars.

ProfessorElisabethHollandDirector, Pacifi c Centre of Environment and Sustainable Development (PaCE-SD).

NotefromtheDirector

iii


Pacificcoastsareconstantlychangingasaresultofnaturalprocessessuchastides,strongcurrents,rain,stormsurges,strongwind,cyclonesandsealevelrise.Withincreasinghumanactivitieswithinthecoastalareas intermsofhumansettlement, landusechanges,flowofsolidandliquidwasteandcoastaldevelopmentssuchasbeachramps,jetties,causeways,coastalprotectionstructures,reefminingandextractionsofsandandbeachaggregates,thereiseverincreasingchangealongPacificcoasts.Inaddition,climatechangeandclimatevariabilityandextremeweathereventshaveexacerbatedtherateofchangeofPacificcoasts.

Thecoasthasbeendefinedasthezonewherethelandandseameet.ThemainfeaturesofPacificcoastsaredominatedbycoralreefs,reefridges,inter-tidalridges,beaches,cliffs,waveactionsandmangroves.PacificcoastsaredesignatedimportantareasforprovidingvitalPa-cificlivelihood.Thecoastalecosystems,humansettlementandothermajorsupportingservicesandbasicinfrastructurearecentredonthecoastalzone.Coastsarebeingusedformanyrea-sons.TheunderlyingproblemisthatPacificcoastsareinastateofcrisis.AnumberofhumanengineeringinterventionsoverthepastdecadehavecontributedandacceleratedthecoastalerosionprobleminthePacificregion.ThePacificcoastlineisover50,532kmlong.Bothnatu-ralprocessesandhumanengineeringworkareblamedforcausingcoastalerosion.Thisguidehasbeenproducedtoinformandassistcoastalexperts,managers,andPacificcommunitiesunderstandthevariousmeasurestheycantaketoreducecoastalerosion.

CoastalprotectioninterventionsinthePacificbasicallyfallintotwocategories:non-structuraladaptationand structural adaptationapproaches. Thebestpracticeson coastal protectionthatareviewedasnon-structuralwereidentifiedas:

•Knowledgeofcoastalprocesses •Policyonworkingalongsidewithnatureandnotagainstit •Retreat,accommodateandprotectapproach •EnvironmentalImpactAssessmentframework •Foreshoreregulation •LocallyManagedMarineAreas,MarineProtectedAreasandConservationAreas •NationalBiodiversityStrategyandActionPlan •IntegratedCoastalZoneManagementapproach •Adopt‘ridgetoreef’approach •Establishedengineeringstandardframework •ActiveBuildingCode

ExecutiveSummary

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Interventionsthatwereclassifiedasstructuralfallintotwoparts:Thesoftmeasuresandthehardmeasures.Thesoftmeasureapproachesidentifiedincluded:

•Maintainingahealthyreefislandsandislets •Protectionandrestorationofseagrassandalgalecosystems •Maintaininghealthyfringingandbarriercoralreefs •PlantingMangroves •Plantingcoastalvegetation(littoralplants) •StabilizingCoastalbeaches •Beachnourishment

Thehardmeasureapproacheswere:

•Seawalls •Groynes •Revetments •Gabions •Breakwaters •GeotextileContainers

Selectedexamplesofcurrentcoastalprotectioninterventionsarepresentedinpictorialforms.These included examples from the Cook Islands, the Federated States ofMicronesia, Fiji,Guam,Kiribati,Nauru,Niue,theNorthernMarianas,Samoa,theRepublicofMarshallIslands,Palau, PapuaNewGuinea, Tonga, Tuvalu, the Solomon Islands, Vanuatu, and Timor Leste.Someexamplesofunsuccessfulinterventionswerealsocaptured.

ThereportisintendedasageneralguidetocoastalprotectionpracticesinthePacificregion.Theoptionspresentedinthisguideshouldbeexaminedcarefullybyqualifiedengineerspriortoselectionandimplementation.

ThereportendedwithexcellentexperiencessharedthroughthePSEnetworkandsomeim-portantcasestudies.

V


ListofTables

Table1:MarineAreas,ReefAreasandCoastlinesinPICTs. 5Table2:ComparisonofMarineManagedAreasinthePacificregion. 18Table3:Comparisonofcoastalprotectionframeworks. 23Table4:ComparisonofPICTswithorwithoutcoastalprotectionframeworks. 25Table5:HardEngineeredSolutionAlternatives. 34Table6:Seawallcomponents. 35Table7:SeawallAlternativesComparisonSummary. 36Table8:RevetmentAlternativeComparisonSummary. 38Table9:GroyneAlternativeComparisonSummary. 40Table10:BreakwaterAlternativeComparisonSummary. 41Table11:HardEngineeredSolutionsOverview. 44

ListofFigures

Figure1:MapofthePacificregion. 4Figure2:Thedepositionalenvironments. 6Figure3:Longshoredriftcurrent. 7Figure4:ExamplesofcoastalerosioninthePICTs. 8Figure5:Typicalbeachsystems. 13Figure6:ConstructiveandDestructivewaves. 14Figure7:Retreat,AccommodationandProtectstrategies. 17Figure8:ExampleofapollutedcoastalenvironmentinFongafale. 28Figure9:TheseagrassSyringodium isoeti folium. 29Figure10:Ahealthyislandreflectsintoahealthyreefsystem. 30Figure11:PlantingmangrovesinTuvalu. 31Figure12:Thesemangroveroots. 32Figure13:TheTuvaluForamSandProject. 33Figure14:Foraminifera. 33Figure15:TypicalRockRevetmentSection. 37Figure16:RenoMattressSectionExample. 37Figure17:Schemeofinteractionofgroyne,waves,currentsandshore. 38Figure18:RockGroyneExample. 39Figure19:ConventionalMulti-LayerRubbleMoundBreakwater. 40Figure20:RockBreakwaterExample. 41Figure21:GeotextileSand-filledContainer-Groyneexample. 42Figure22:GeotextileSand-filledContainer-Seawallexample. 42Figure23:GeotextileSand-filledContainer-Revetmentexample. 43Figure24:GeotextileSand-filledContainer-Breakwaterexample. 43Figure25-32:ExamplesofengineeringworksinCookIslands. 46Figure33-34:CoastalinterventionsinEastTimor(Timor-Leste) 46Figure35-38:EngineeringstructuresinFSM. 47Figure39-64:EngineeringstructuresfoundinFiji. 48Figure65-88:CoastalprotectioninterventionsinKiribati. 50Figure89-101:EngineeringstructuresinRMI. 52Figure102-113:CoastalstructureinNauru. 54Figure114-121:Naturalandman-madestructuresinNiue. 55Figure122-131:EngineeringworksinPalau. 56Figure132-136:CoastalinterventionsinPNG. 57Figure137-140:CoastalinterventionsinSamoa. 58Figure141-150:CoastalstructuresinSolomonIslands. 58Figure151-154:EngineeringstructuresinTonga. 60Figure155-171:EngineeringstructuresinTuvalu. 61Figure172-175:CoastalinterventionsinVanuatu. 62Figure176-178:ExamplesfromCookIslands. 63Figure179-184:ExamplesfromFiji. 64Figure185-186:ExamplesfromFSM. 64Figure187-200:ExamplesfromKiribati. 65Figure201:ExamplefromSamoa. 66Figure202-207:ExamplesfromTuvalu. 67Figure208:TraditionalMPAinVanuatu. 70Figure209:Vetivergrassfullygrown. 72Figure210:PlantingofVetivergrassnearriverbank. 72Figure211-213:CliffsinNiue. 73Figure214:GISmap. 75Figure215:Designofsand-bagseawall. 76Figure216:Relocationhomes. 77Figure217:Niuecliff. 77

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T a b l e o f C o n t e n t sAcknowledgement iAcronyms iiNotefromtheDirector iiiExecutiveSummary ivListofTables viListofFigures vi

C h a p t e r 1 IntroductionbyLukePaeniu,Dr.HélèneJacotDesCombe,AshmitaDeviandPriyaSharma

1.1 Definition:WhatdowemeanbyCoast? 11.2 WhyareCoastsImportant? 11.3 TheProblem:What’swrongwithPacificCoasts? 41.4 ThePurpose:Whatisthisreportfor? 91.5 Thestructureofthereport 101.6 Methodology 10

C h a p t e r 2 NonStructuralInterventionsbyLukePaeniu,ViliamuIeseandPriyaSharma

2.1 Non-structuralOptions: 112.1.1 Understandingthewaycoastalprocesseswork 112.1.2 Adoptapolicyofworkingwithnatureasthebestwayforward 162.1.3 AdoptAdaptiveResponsestrategies:retreat,accommodateorprotectionapproach 162.1.4 ConductanEnvironmentalImpactAssessment 172.1.5 EnforceForeshoreRegulations 182.1.6 AdoptMarineProtectedAreas(MPAsorMMA) 182.1.7 AdoptNationalBiodiversityStrategyandActionPlan(NBSAP) 192.1.8 AdoptanIntegratedCoastalZoneManagementApproach(ICZM) 192.1.9 Adopt‘RidgetoReef’approach 212.1.10Settingengineeringstandards,takingresponsibilitiesandcomplyingwithcodesofethics 222.1.11 AdoptaproperBuildingCode 23

C h a p t e r 3 StructuralOptionsbyLukePaeniu,AntoineDeRamonN’Yeurt,KerrynChungandNicholasHobgood

3.1 Introduction 263.1.1 StructuralEngineeringOptions: 263.2 Softstructuralengineeringoptions: 263.2.1 NaturalSoftEngineeringStructures: 263.2.1.1Maintaininghealthyreefislandsandislets 273.2.1.2Improveseagrassandalgal/seaweedecosystems 283.2.1.3Maintainhealthyfringingandbarriercoralreefs 293.2.1.4PlantingMangroves 303.2.1.5StabilizingCoastalBeaches 32


3.2.1.6PlantingCoastalVegetation(littoralplants) 333.2.1.7BeachNourishment 333.3Hardstructuralengineeringoptions 333.3.1Seawalls 343.3.2Revetment 363.3.3Groynes 383.3.4Breakwaters 403.3.5 GeotextileContainers(InnovativeSolution) 413.3.6 HardEngineeredSolutionsOverview 44

C h a p t e r 4 SelectedExamplesofCurrentInterventionsinthePacificbyLukePaeniuandAlitiKoroi

4.1CookIslands 464.2EastTimor(TimorLeste) 474.3FederatedStateofMicronesia(FSM) 474.4Fiji 504.5Guam 504.6Kiribati 504.7MarshallIslands 524.8Nauru 534.9Niue 554.10NorthernMarianaIslands 554.11Palau 564.12PapuaNewGuinea 574.13Samoa 574.14SolomonIslands 584.15Tonga 604.16Tuvalu 614.17Vanuatu 624.18Interventionsthatdidnotwork 63

C h a p t e r 5 SelectedExamplesofPacificExperiencesbyLukePaeniuandIsoaKorovulavula

5.1HardCoastalStructures 685.2SoftCoastalStructures 695.3BiophysicalStructures 735.4CoastalAdaptationMechanism 745.4.1Participatoryapproach 745.4.2ToolsandDesigns 745.4.3Relocation 775.5AssessmentofCoastalErosioninFSM 775.5.1ScientificapproachestoCoastalManagement 78

C h a p t e r 6 Conclusions 79References 80

B E S T P R A C T I C E S C O A S T A L P R O T E C T I O N 12

1.1 Definition:WhatdowemeanbyCoast?

Coastisabroadtermthatcanbedefinedby:“thepartofthelandadjoiningornearthesea”(Oxfordonlinedic-tionary).

Inthisreport,wewillusethetermPacificCoastwhichinthiscontextmeansthezonewheretheoceanandlandinteract.Thiszoneistheareaimpactedbymarinefactorssuchaswaves,wind,saltsprays,andsaltwaterintru-sion.Thiszoneisexposedtosealevelrise,extremeweatherevents(stormandcyclones)andtidalevents,coastaldevelopmentandmarinepollution.Forsomeatollcountries,almosttheentireislandsandassociatedisletsmaybedefinedascoastalarea.ThedistinctionbetweenPacificcoastsascomparedtocoastsinmostdevelopedcoun-triesliesintheircharacteristics.InthePacificregion,coastalphysicalfeaturesinclude:

•“Coralreefs1whichareacommonandoftendominantfeature •Waveconditionswhichvarysignificantlyintimeandlocationthroughouttheregion •Waterlevelsandcurrentsinthecoastalzonewhicharestronglymodifiedbyfringingreefs •Naturalbeachmaterialwhichiscommonlyandoftendominantlysuppliedfromcarbonatesources •...Mangroves,wheretheyoccur,areaprominentandimportantfeatureofthecoast.”2

1.2 WhyareCoastsImportant?

ThePacificregion’scoastsarewellknownfortheaestheticbeautyoftheirpristinesandybeaches;crystalclearwaters,naturallyformedrocksandlimestoneandtheyareblessedwithcolorfulcoralreefs.3Theyarerichwithdiversecoastalhabitatsandecosystems.

1 Bryne(1994)2 SOPAC(1994)3ibid

Chapter 1: IntroductionbyLukePaeniu,DrHélèneJacotDesCombe,AshmitaDeviandPriyaSharma

C O A S T A L P R O T E C T I O N B E S T P R A C T I C E S 02

However,Pacificcoastsarealsoprovidingroomforhumansettlements:housesandvitalbasicinfrastructureandassetssuchasroads,powerstations,wharves,hospitals,schoolsetc.,arelocatedwithinthecoastalareas.4ItisestimatedthatthepopulationofPacificIslandswhichnumberedaround8.6millionin2000iscurrentlyclosedto10million(SPC,2013)andthat“morethan80%ofPacificIslandersliveinornearcoastalareas”.5Infact,“almost 100 % of Pacific islanders (excluding those in Papua New Guinea) live within 100 kilometers of the coast.” 6

Thesehumanactivitiesandthecoastalecosystemsprovidethesupport forPacific livelihoods,either throughtraditionalactivitiessuchasfishingormoremoderntypeofemploymentinindustryandservices.

“These fragile ecosystems not only support the fisheries and agriculture that the people of the [Pacific] region depend on for food and income, they also provide shoreline protection, places for recreation, [shared] cultural heritage, and many other benefits all of which are at risk from climate change and local stress caused by human activities.” 7

“The shallow ecosystems and productivity of mangroves, seagrass beds, coral reefs and inter-reef seabed are critical natural assets for food production, food security, cultural and recreational activities and livelihoods for many people in Pacific Island States. They also provide important ecosystem services in protection of coasts against storm surges and in production of carbonate sands and debris to nourish beaches and maintain islands. These ecosystems are easily damaged through reclamation, drainage, pollution and destruction of critical habitats for fish and other food species. Once destroyed, these ecosystems are not readily or cheaply restored or replaced.“ 8

“The vital commercial and national assets, essential infrastructure, and populations of most Pacific Island Countries lie in the coastal zone.” 9

However,thedevelopmentofhumanactivitiesaroundthecoastalareasisblamedfordegradingcoastsofthePacificregion.

4SOPAC(1994)5 Howarth(2010)

6RamBidesietal.(2011)7 Keeneretal.(2012)

8 Kenchington(2009)p.19 SOPAC(1994)


“Given that most of the region’s population is settled in coastal areas, changes in population density combined with new technology and changing development priorities have had a significant impact on coastal environments in the last decade” 10

Pacificcoasts,andmostspecificallycoastalecosystemssuchasmangroveforestsandcoralreefsalsoprovidepro-tectionforthelandbyactingasfirstnaturallinesofdefense.

Tosummarize,peoplearemotivatedtoliveonthecoastforanumberofreasons.Coastsoffer“fertile lowland, abundant marine resources, water transportation, aesthetic beauty, and intrinsic values”. 11Thecoastisthecentreofmajoractivitiesthatinclude“commercial,recreational,andsubsistencefisheries;portsandindustrialfacilitiesthatrelyonshippingfacilities;andtourism,agricultureandforestry…”12

However, over the years, this natural beauty and ecosystem integrity has slowly eroded as coasts havebeenchanged,modified,degradedandre-shaped.BothnaturalprocessesandhumaninterventionareinvolvedinthechangesofthePacificCoasts.

Theimportanceofthecoastscanbereflectedinthewayhumansusethecoast.HerearesomeofcurrentusesofPICTsshorefrontthatwererecordedinMaharaj(2000):

•Mariculture(pearlandshellfish)e.g.intheCookIslands, •Subsistencereeffishing,e.g.inallPICTs, •Fillsites,e.g.inmangrovessystemsthroughoutthePICTs, •Liquidwaste(effluent)disposal,e.g.inindustrialareassuchasLami,FijiIslands, •Maritimeandlanddefense,e.g.FijiNavy,FSMPatrolinKolonia,Pohnpei, •Recreationandtourismdevelopment,e.g.touristresortslikeSheraton’sDenarauIslandResortin theFijiIslands, •Landreclamation,fillandhousingdevelopment,e.g.inpartsofalmostallmangroveareasthroughout thePICTssuchasinKosraeandYapStates,FSM, •Constructionofcoolingwaterinletsandoutletse.g.NauruPowerFacility,Nauru, •Constructionofsewageoutfalls/outlets,e.g.onthewestcoastofNauru, •Constructionoftidalinletsandriver-mouthengineeringworks,e.g.RewaRiver,FijiIslands, •Constructionofcoastalprotectionstructureslikeseawalls,groynes,revetments,breakwaters,gabion basketsandbioengineeringprotection,e.g.generallycommonthroughoutthePICTs, •Constructionofpromenadesandinfrastructurefacilities,e.g.coastalroadsinNauru,FSM,Fiji,Kiribati, NewCaledonia,CookIslandsandSolomonIslands, •Constructionofjetties,boatchannelsandmooringfacilities,e.g.Honiara,SolomonIslandsandPort Vila,Vanuatu, •Constructionofindustrialandrecreationalportsandharbors(commercialportsandyachtclubs),e.g. SuvaYachtClub,FijiIslands, •Constructionandlayingofunderseatelecommunicationcables,e.g.CableandWirelessundersea fiberoptictelecommunicationcables,LaucalaBay,FijiIslands, •Constructionandlayingofpipelinesforfluidtransfer(oilandgas,water,industrialproductsandwaste),e.g.VudaPoint,FijiIslandsandKolonia,FSM,

10 Howarth(2010)p.911 GilbertandVellinga(1990)12 ibid

03


•Constructionofresidentialandcommercialbuildings,e.g.throughoutthePICTs, •Marineaggregateextraction(sand,gravel,bouldersandcoral-mining),e.g.throughoutthePICTs, •Onlandquarryoperations,e.g.Vanuatu,FijiIslandsandFSM, •Metalliferousminingandhydrocarbonexplorationandproduction,e.g.PapuaNewGuinea, •Agricultureandforestry,includingtimberandcoconutproduction,e.g.andFijiIslandsandtheSolomonIslands •Protectionandnaturalresourceconservation(marineparksandprotectedareas),e.g.inNewCaledoniaandFrenchPolynesia

1.3 TheProblem:What’swrongwithPacificCoasts?

1.3.1:Theissue

Lookingattheglobalscenario,theworld’scoastsareincrisisbecauseoftheincreasinghumanpopulationlivingincoastalareas(Hinrichsen1995).Theauthoralsoarguedthatthecoastsare“over-developed, over-crowded and over-exploited.” 13InthePacificregion,coastsaredefinitelyinastateofcrisisaswell.ThePacificregionismadeupof23nations14:AmericanSamoa,CookIslands,Fiji,TheFederatedStatesofMicronesia,Guam,Kiribati,TheMarshallIslands,NewCaledonia,Niue,TheNorthernMarianaIslands,Nauru,Pitcairn,Palau,FrenchPolynesia,PapuaNewGuinea,Samoa,TheSolomonIslands,TimorLesteTokelau,Tonga,Tuvalu,VanuatuandWallisandFutuna,thatarescatteredoveravastPacificOceanofsome30millionkm2(Figure1).15

Figure 1 Map of the Pacifi c region. Adapted from Govan (2009) p.13.

13Hinrichsen(1995)14SPC(2013)

15 Haberkorn(2008)

04


PICTs Marine Area (km2) Reef Area (km2) Reef at Risk (%) Coastline (km)

American Samoa 390,000 67 42 116

Cook Islands 1,830,000 212 57 120

Fiji 1,217,000 10,020 68 1,129

FSM 2,980,000 3,172 45 6,112

Guam 218,000 183 100 126

Kiribati 3,800,000 1,967 48 1,143

RMI 2,131,000 1,995 3 370

New Caledonia 1,740,000 4,573 13 2,254

Niue 390,000 15 43 64

Northern Mariana Islands

1,823,000 102 0 1,482

Nauru 436,000 10 100 30

Pitcairn Island 800,000 39 0 51

Table1:MarineAreas,ReefAreasandCoastlinesinPICTs(ModifiedfromGovanatal2009SPREP)

Palau 601,000 709 0 1,519

PNG 2,366,000 13,840 46 20,197

French Polynesia 5,030,000 3,000 29 2,525

Samoa 120,000 200 95 403

Solomon Islands 1,630,000 5,750 46 9,880

Tokelau 290,000 97 0 101

Tonga 700,000 3,587 46 419

Tuvalu 757,000 872 15 24

Vanuatu 680,000 708 70 2,528

Wallis and Futuna 300,000 425 26 129

Timor Leste n/a 35 n/a 735

Table1aboveshowssomeinterestingstatistics.PapuaNewGuineahasahugecoastlineof20,197kmfollowedbySolomonIslandswith9,880kmandFSMwith6,112km.Tuvaluhasthesmallestcoastlineofonly24kmfol-lowedbyNauruwith30km.Intermsofmarineareas,FrenchPolynesiahasthebiggestareawith5millionkm2 whileKiribatihas3.8millionkm2andFSMwith2.98millionkm2.CountrieswithreefsathighriskareNauruandGuamfollowedbySamoaandVanuatu.

These23nationswerehometoapopulationof8.6millionin200016andthispopulationincreasesregularly.ItisestimatedthatthecurrentpopulationofthePacificismorethan10millionandprojectionsfor2035willincreasethisto15millionpeople.17Outofthe8millionpeoplein2000,PNGhasashareof70%.Melanesian’scountrieshadthehighestshareofthepopulationof88%,comparedwithPolynesianislandswith7%whileMicronesian’snationshad5%.18

MajorinfrastructuresthatareimportantinsupportingbasicservicesforPacificpopulationsarealsolocatedwith-inthecoastalareas.19Therefore,theescalatingPacificpopulationnotonlyputsextremepressuresonresourceswithinthePacificcoasts;humanactivitiessuchascoastalengineeringworkonthecoasts(buildingwharves,seawalls,beachrampsandrevetments)allplayamajorroleinthechangingnatureofthePacificcoasts.20

The “introduction of hard-engineered structures has exacerbated island erosion and degraded ecological process.” 21

16SPC(2013)17 ibid18 ibid19 SOPAC(1994)20 OceanPolicyResearchFoundation(2009)21 Kench(2009)p.22

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1.3.2:TheCauses

Gillie(1997)statedthatPacificcoastsaresubjecttocontinualchange.Bothnaturalprocessesandhumanactivi-tiescontributetoseverebeacherosionsinthePacific.22Theshapeofthecoastlinedependsonthebalancebetweenmaterialdepositandremoval.Naturalprocessessuchaswaves,watercurrentsandextremeeventssuchascyclonesarethemainfactorsaffectingthecoast.

“Coastal processes are hydraulic and sedimentary process driven by ti des, currents, waves, coastal winds and tsunamis. Forces exerted by wind and water act on the ocean fl oor and shore face to drive currents, move sediments, erode exposed bedrock and shape the coastline, estuaries and the nearshore seabed.” 23

Figure 2: The depositi onal environments (GeologyCafe, 2012)

Thematerialsthataretransportedgetdepositedtoaparticularlocation,duringthedepositionprocess.Deposi-tioncanincludesand,sedimentandshingle.Therearefourmaindepositionenvironments:beaches(depositionofsand,singlesetc.betweenthehightideandlowtidemark),spits(long-termdepositionthatformslongnarrowridgefromthecoastline),bars(growlikespitsbutjointoheadlands)andtombolos(spitgrowsoutwardjoiningoffshoreislandandland)(Gore,2010).

22 Gillie(1997)23Cummingsetal.(2012)p.9

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Figure 3: Longshore drift current (RegionWorld, 2007) and causes of erosion on cliff s (Geographypods. 2012)

TheseaisconstantlymodifyingtheshapeofthePacificcoastline.Thisishappeningduetowaveactionsinerod-ing,transportinganddepositingmaterials.Whenwavesapproachfromthedeepoceantheymove incircularformsknownasswells.Astheyapproachshallowwater,wavesbecomesteeperandeventuallycollapsecreatingaswash(thewhitefoamthatreachesthebeach).Thereturnwaveisknownasthebackwash.Onbeaches,whenwashisstrong,itbringsmaterialthatfeedsthebeach,whilethismaterialcancauseerosionatthebaseofcliffs(Figure3).Strongbackwashwillremovematerialfromthebeachesandcausecoastalerosion.

Alongshoredriftoccurswhenwavesentertowardsthecoastalzoneatanangle.Theswashwavesmovesupthebeach,carryingthematerialupandalongthebeach.Ontheotherhand,thebackwashcarriesmaterialsbackdownthebeachatrightangles.Thisprocesscausesaslowmovementofthematerialalongthebeach.Longshoredriftlinkstheerosionanddepositionprocessesbycausingerosionofmaterialsatoneplace,whichisthentrans-portedanddepositedatanotherlocation(RegionWorld,2007).

Anychangeincoastalecosystemsuchasmangroveforestdestruction,orbuildingofstructureonthecoastwillaffectthesenaturalprocessesandmayleadtomorerapiderosion

“Shoreline alterati ons, mangrove and coral harvesti ng, dredge and fi ll acti viti es, sand and gravel extracti on and disposal of waste in the marine environment all result in changes to the natural character of the coast.” 24

Coastalerosionandchangeinshorelinecanbeobservedonmanyislandsintheregion.

24GilbertandVellinga(1990)

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Figure 4: Examples of coastal erosion in the Pacifi c Island countries. a) Fiji: severe coastal damage at Laucala Beach Estate, Suva following cyclone Mick in December 2009; b) Palau: eroded coastline in Koror State; c) Kiribati : unprotected coast at Ewena Village, Abaiang Island; d) Tonga: beach erosion exacerbated by constructi on of jett y at Ha’afeva, Ha’apai

1.3.3SomeExamplesofCoastalProtection

BecauseofseriousconcernsofthechangingnatureofPacificcoasts,thePacificregionwasunderextremepres-suretolookforquickeasyfixestothedegradingcoast,andbecamethehubofwhatisbelievedtobeatestinggroundofhardengineeringstructures.Pacificnationsdeliberatelytakeonboardsomeofthesoftandharden-gineeringstructureswiththeprimaryaimtoprotecttheadverseeffectoferodedcoastlinesandtomaintainitsoriginalnaturalbeauty.

Chapter4containsmanyillustrationsofthetypesofcoastalprotectionpracticesusedinPacificCountries.

Therewere‘failure’and‘success’storiesoftheseengineeringinterventionsintheregioninwhichconstructivelessonsandbestpracticesmeasureshavesurfaced.Gillie(1997)arguedthatcoastalgeologyandcoastalengi-neeringinthePacificaresitespecificbecauseofthelargescalegeographicalvariationsinnaturalprocessesandresponses.Thiswasconfirmedbythe informationcollectedthroughthePSEnetwork,confirmingthatcoastalprotectioninterventionisnota‘onesizefitsall’strategythatmaybeappliedacrossPacificcommunities.

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Inadditiontopresentnaturalprocessesandhumaninterventions,climatechange,sealevelriseandextremeweathereventsexacerbatethedegradingcoasts.Theprojectionsconcerninglow-lyingcoastspresentedintheInter-governmentalpanelofscientificscientistsonclimatechange(IPCC)AR4areequallyofconcerntothePa-cificregion:

1. “Coasts are experiencing the adverse consequences of hazards related to climate and sea level (very high confidence).” 2. “Coasts will be exposed to increasing risks, including coastal erosion, over coming decades due to climate change and sea-level rise (very high confidence).” 3. “The impact of climate change on coasts is exacerbated by increasing human-induced pressure (very high confidence).” 4. “Adaptation for the coasts of developing countries will be more challenging than for coasts of developed countries, due to constraints on adaptive capacity (high confidence).” 25

IntermsofNaturalhazards,thePacificregionranksamongthemostvulnerableintheworld.26Intermsofchang-estocoastlines,themostdamaginghazardsaretropicalcyclones,floods,stormsurgesandtsunami27.Unfortu-nately,thesehazardsarequitefrequentintheregion,withseveraltropicalcyclones(e.g.TCEvaninSamoaandFijiin2012andTCIaninTongain2014)andtsunamis(SamoaandTonga2009,SolomonIslands2007and2013).Floodschangethecoastlinebydepositingmorematerialonthecoastbutalsobydamagingcoastalecosystemsandstructures(e.g.floodsinNadiandBa,2011and2013).

1.4 ThePurpose:Whatisthisreportfor?

WehavedescribedtheimportanceofPacificcoastsandtheproblemstheyarefacingintheprevioussections.ThepurposeofthisdocumentistoprovidegenuineinformationandguidanceonBestPracticesthatmaybeusedbyPacificCommunitiestoimprovetheirresiliencetotheimpactofclimatechange,sealevelriseandextremeweathereventswithreferencetocoastaladaptationprotectionsmeasures.

Bestpractices inthiscontextreferstoaprocessor interventionthathasstoodthetestoftimeandhasbeenproventoworkoverlongperiods.Someofthecriteriausedincludebeinganeffective,successfulandsustainableintervention,ithastobeenvironmentalfriendly,technicallyfeasible,economicallyaffordableandinvolvethekeystakeholders-(FAOGoodPractices).

Thisguidehasbeenproducedtohelpcoastalexperts,managers,andPacificcommunitiesunderstandthevariousmeasurestheycantaketoreducecoastalerosion.Theguidehasbeenmadetobeuser-friendlyandwasbasedonlongtermexperiencesofPacificCountries.ItisintendedforPacificcommunities,localauthorities,nationalgovernments,donors,coastalengineers,coastalmanagers,non-governmentorganizations,andstakeholdersin-volvedinplanning,anddesigning, implementingcoastalprotectioninterventions.It isprimarilydesignedasareferenceforcoastalpractitionersinvolvedindesigningcoastalprotectioninterventionsinthePacific.Theguide-linesprovidedarebroad,genericandnon-prescriptive.

25 Nicholls,etal.(2007)chapter626Bettencourtetal.(2006)27 Ibid

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Therationalesbehindtheconceptionofthisguidearemanyfold:

• Pacificcoastsareincrisis • ThereisanurgentandincreasingneedforPacificcommunitiestoadoptquickfixsolutionsto theirdegradedcoastalecosystems • Manyofthecurrentcoastalprotectioninterventionsareineffective • Coastalerosionanddegradedcoastalecosystemsarecontributingtoanalarmingincreasein thefrequencyofcoastalhazards • Pacificcoastsareasourceoffoodandlivelihoodsecurity • Thevitalbasicinfrastructures,assetsandcoastalpopulationsinPacificcountriesareatgreat riskandfutureprojectionsarequitealarming. • Populationgrowth,extremeweatherevents,climatechangeandclimatevariabilityare exacerbatingtheriskofcoastalerosionanddegradedcoastalecosystemsinthePacific. • EndangeredcoastalassetswillrenderimpossibleeffortsbyPacificcountriestomeettheir MDGsgoals,inparticularthoserelatedtopovertyalleviation.

1.5 Thestructureofthereport

ThestructureofthisreportisdesignedinawaythatitwillhelpguidePacificcommunities,coastalengineersandmanagerstoplanfuturecoastalprotectioninterventions.Thereportincludes:

Chapter1-BriefexplanationofwhyPacificcoastsareimportant,theproblemsfacingPacificcoasts,the purposeofthereport,structureandmethodology; Chapter2-Itprovidesbestpracticesonnon-structuralengineeringstructuraloptions; Chapter3-Structuralengineeringoptions(softandhardmeasures); Chapter4-UpdateonselectedexamplesofcurrentstructuralcoastalinterventionsinthePacific;and Chapter5-SelectedexamplesofPacificexperiencesincoastalprotections.Mostoftheinformation gatheredthroughthePSEnetworkissharedinthischapter.

1.6 Methodology

TheprincipalaimofthisresearchistoconsolidateasmanybestpracticesfromaroundthePacific,aspossible,oneffectivecoastalengineeringinterventionsforprotectingthePacificcoast.Theresearchbeginswithaquerypostedthroughtheclimatechangeexperts’network-thePacificSolutionExchange.Thetwomainqueriesthatweremadewere:

•Shareexperiences(goodpracticesandlessonslearnt)oncoastalprotectionmeasuresand suggestsomesolutionstotheproblem •Provideexamples(toolkits,technologiesetc.)fordesigningandimplementingcoastal protectionmeasures.

ThenextapproachwastoconductaliteraturereviewofcoastalengineeringworkinthePacific.In-CountryCoordinators(ICCs)from15PacificislandscountriesweretaskedtoupdatepartsofChapter4inthisreport.PaCE-SDhasbeeninstrumentalinestablishingareviewcommitteetoproducethisreport.

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2.1 Non-structuralOptions:

Many interventionsondevelopingcoastalprotectionmethods in thePacific regionprovide lessons frombothgoodandbadexperiencesinthefield.SomeoftheadaptationapproachesthathavebeenintroducedinthePa-cificfallintotwoseparatecategories:Non-structuraloptions;andstructuraloptions.Non-structuraloptionsareinterventionsthatareextremelyusefulandarerequiredinprotectingthecoastlinefrombothhumaninducedandnaturalshocks.Theseareinstrumentstosafeguardthenaturalcoastlinezonesandpromotetheresilienceandofferprotectionofcoastlinesystems.Furthermore,theyarealsoimportantpre-requisites(planningandmanage-mentprocesses)put inplacetoguideandensurehumaninterventionstosafeguardthecoastlinesystemsarecarriedoutinamoreefficient,effectiveandsustainableway.Italsoencouragesthechangeinindividualbehaviorandattitude.

2.1.1Understandingthewaycoastalprocesseswork

Pacificcommunitiesmustfirstattemptto,asapre-requisite,obtaininformationoncoastalprocessesandtryandunderstandhowtheyworkbeforedevelopingtheideaofapplyingstructuraloptionstoprotectthecoast.Col-latingthisbasicinformationisvital,asitwillhelpcontributetowardsdesigningabetteradaptationapproachtocoastalprotectionforthecommunity.Someoftheseprocessesarehighlightedbelow:

Coastalenvironmentsareinfluencedbyastronomicalprocesses(effectsofgravitationalforces),meteorologicalprocesses(interactionofstorms,rainfallandclimatechange),tectonicmovements;hydrologicalprocesses(in-teractionsofwavesandcurrentsandwaterlevels),sedimentprocesses(wavesandcurrentsandtransportsedi-ments)andsocialprocesses(anthropogenicinfluences).

Chapter 2: Non structural interventionsbyLukePaeniu,ViliamuIeseandPriyaSharma


“Coastal processes are hydraulic and sedimentary process driven by tides, currents, waves, coastal winds and tsunamis. Forces exerted by wind and water act on the ocean floor and shore face to drive currents, move sediments, erode exposed bedrock and shape the coastline, estuaries and the near shore seabed.” 28

Itwouldbeidealtounderstandthatthereisaphysicalprocessthatinvolveswind,waves,tidetemperatureandsealevelrise.Thereisalsoabiologicalprocesswhichinvolvescoralandmarinespecies.Coastalprocesseshelpbreaksedimentsandtransportitalongtheshoreline.

Therearethreemainprocessesthatalterandsupporttheformationofthecoastalzone:erosion,transportationanddeposition(Summerfield,1991)thatarediscussedindetailinthissection.Erosionisaprocessofgeologicalfeaturesbeinggraduallywornaway.Itisusuallycausedbytheactionofwindsandthecurrentsontherocksandsediments.Depositionistheaccumulationofsedimentontheseafloor,lakesandrivers(orofsolidparticlesfromtheatmosphereontothelandoroceansurface)(Segar,2007).Transportationistheworkofwavesandtidesintransferringthebrokenmaterialsonthebeachsomewhereelse(NSIDC,2008).

Formation of coasts

Mostofthecoastsareclassifiedaseithererosionalordepositionalcoastsdependingontheirformationfactorbeingeitherfromerosionordepositionofsediments.Erosionalcoastsdevelopwheretheshoreisactivelyerodedbywaveactionorwhereriversorglacierscausederosionwhensealevelwaslowerthanitisnow.Depositionalcoastsdevelopwheresedimentsaccumulateeitherfromalocalsourceorafterbeingtransportedtotheareaintheriversandglaciersorbyoceancurrentsandwaves(Segar,2007).Volcaniceruptionsandearthquakescancauseinstantformationofcoasts.However,sealevelchangeandcoralreefgrowthcauseslowcoastformation.

28 Cummingsetal.(2012)


Figure 5 Typical beach systems (Short, 2012)

Hydrodynamics of Oceans waves -itisusefultounderstandhowwavesoperate.Wavesarecreatedwhenwindblowsoverthesurfaceoftheocean.Theimportantfactorsthatdeterminethefeaturesofwavesare:

“the strength of the wind The distance of the water The length of ti me for which it blows” 29

Alltheabovedoinfluencetheheightofwaves.Inaddition,thedepthofwaterisalsoafactorthatinfluenceswaveheight.Thisisimportantforlow-lyingcoralreefislands.Thewaveformedalongacoralreefdependsonthelevelofoffshorewaves,whichisnormallybetween0.2-0.5m.Thewave’sheightatsomedistancefromtheridgeiscloseto0.55-0.65m.Fringingreefsareusefulinreducingwaveenergyandwaveheights(SOPAC,1990).Aswavesapproachtheshore,theymakecontactwithseabed,reefsandisland.Thewaveschangeintheformofrefraction(wavesbendinlinewithseabedcontours)orreflection(wavesarereflectedbackwhenblockedbysolidobject)ordiffraction(wavesspreadoutbehindbreakwaterorisland)orfriction(waveenergyandheightarereducedclosetoshore)orshoaling(wavesincreasesinheightsfromdeepwaterlevelsuntiltheybreakandthenreducesrapidlyinheight.)30Soitisimportantthatweknowhowthechangesthatwemakeatthecoastwillaffectandcausechangesinwavepatterns.

TheseaisconstantlymodifyingtheshapeofPacificcoastlines.Thisiscausedbyactionsofwavesineroding,trans-portinganddepositingmaterials.Whenawavesapproachesfromdeepoceanitmovesincircularformknownasswell.Asitapproachesshallowwater,thewavesbecomesteeperandeventuallycollapsecreatingaswash(thewhitefoamthatreachesthebeach).Thereturnwaveisknownasthebackwash.Wavesarecausedbywindblow-ingoverthesurfaceofthewater.

29 Byrneetal.(1990)30ibid

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AccordingtoGillie(1997),thePacificOceanisdominatedbyfourmajorwavecomponents:Prevailingnortheasttosoutheastseasandswellsaccompaniedbyeasterlytradewinds;westerlyseas;shortterm,largeseasandswellsgeneratedfromcyclonesandstorms;seasonalsouthandnorthswellwavescreatedbymid-latitudestorms.31

Waves,currents,stormsurgesandtropicalcyclonescaninonewayortheothercausedamagetostructures,floodingofthecoastalzonebutalsocontributetoreplenishmentofmaterialsincoastalareas.

Figure 7 Constructi ve and destructi ve waves that alters the coastline (Geographypods. 2012)Figure 6: Constructi ve and Destructi ve Waves

Causes of erosion-Erosionisacombinationofmanyfactorssuchas:-sealevellongtermtrends,cyclicaleventssuchasENSOepisodes,resultofhumanactivitiesandseverestorms.32Weneedtounderstandthemovementsofwaves(swashandbackwash).Thereareconstructivewaveswheretheswashisstrongandbringsmaterialtothebeach.Inthiscasematerialsaretransportedanddepositedonthebeach.Ontheotherhandwehavedestructivewavesandthesewavescausederosionbecauseswashwavesareweakbutstrongbackwashtakesawaymateri-als.Thebackwashwilleventuallytakeawaymaterialfromthebeach.

Themaincausesofseaerosionarenaturalandhumaninducedones.

“Naturalcausesincludeshorttermbeachdynamics,changes/cyclesinlong-termweatherpatterns,naturalshore-lineevolutionorre-alignment,sealevelriseandcatastrophicgeoharzardsinthecoastalzone.Humaninducedcausesincludebeachsandextraction,theeffectofsand-trappingstructuresandthereclamationofshorefrontland,andtheconstructionsofseawalls.”33

Therearefourknownwaysthatcoastsareeroded:

1.Attritionistheprocesswherewavescausetherocksandpebblestocollideandbreakup. 2.Corrosion(solution)ischemicalweatheringwheretheslightacidityofseawatercausesthegradual dissolutionofthepiecesofcliffs. 3.Hydraulicpressurewheretheseawaterandairgetstrappedincracksintherocks,whichbuildup pressureandcausesthemtobreak. 4.Corrasion(abrasion)–thisprocessisdrivenbythewaves.Wavespickupthepebblesandrocksand hurlthematthecliffbase,thusbreakingthem(NSIDC,2008).

31Gillie(1997)p.18132SOPAC(1990)

33Gillie(1997)p.174

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Transportation

Thewavescausethemovementofthebeachmaterials.Thismovementalongthecoastisknownaslongshoredrift.Longshoredriftoccurswhenwavesentertowardsthecoastalzoneatanangle.Theswashwavesmovesupthebeach,carryingthematerialupandalongthebeach.Ontheotherhand,thebackwashcarriesmaterialsbackdownthebeachatrightangles.Thiswaveactionisowingtothegravitationaleffect.Thisprocesscausesaslowmovementofthematerialalongthebeach.Longshoredriftlinkserosionanddepositionprocessbycausingero-sionofmaterialsatoneplace,transportionandthendepositionatanotherlocation.Somemeansoftransporta-tionare:solution,saltation,suspensionandtraction(RegionWorld,2007).

Deposition

Thematerialsthataretransportedgetdepositedtoaparticularlocation,knownasdepositionprocess.Deposi-tioncanaffectsand,sedimentandshingle.Therearefourmaindepositionenvironments:beaches(depositionofsand,singlesetc.betweenthehightideandlowtidemark),spits(long-termdepositionthatformslongnarrowridgefromthecoastline),bars(growlikespitsbutjointoheadlands)andtombolos(spitgrowingoutwardjoiningoffshoreislandandland)(Gore,2010).

Corals

CoralsareoneofthemainfeaturesofPacificcountries.TherearefourtypesofcoralreefsfoundinthePacific:

•Fringingreefs •Barrierreefs •Atollreefsand •Reefislands34

CoralreefsareimportantbecausetheyactaslineofdefenseinprotectingallislandsinthePacific.35

“Coralreefsareimportantbecauseofthewaytheyproducecharacteristic coastalmorphologicalstructures,affectswaterlevelsandcurrentswithinthecoastalzone,and ultimatelysupplybeachmaterials(sand,pebblesandboulders)fromwhichbeaches,small islands(islets,motuorcays),andlonglengthofshorelinesareconstructed.”36

Coralreefsalsoplayanimportantroleinreducingwaveenergy.

Other Factors

Tidesaredrivenbygravitationalforces,whichalterthecoastalprocess.Thelowtideexposestheshoretobecomedryafterthehightideandpromotesshorelineweathering.Tidalrangeplaysanimportantroleincontrollingtheverticaldistanceoverhighwavesandcurrentsthatshapetheshoreline.Tsunamisarelargewavescausedbytec-tonicmovementsthatcanchangethecoastlinestructurewithinminutestohours.Relativesealeveldeterminestheshoreline;riseorfallofsealevelchangestheshoreline(Summerfield,1991).

34Gillie(1997)p.18235ibidp.18336ibidp.183-p.184

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2.1.2Adoptapolicyofworkingwithnatureasthebestwayforward

Therearenormallytwooptions.Youeitherworkalongwithnatureoryouworkagainstnature.Pacificcountriesareurgedtoworkalongwithnature.

“Workingwithnaturewillprovemuchmoresuccessfulthanworkingagainstnature”.37

Pacificcommunitiestendtofollowasimilarpattern,whenitcomestoprotectingthecoast,theveryfirstthingthatspringstomindistostrengthenseawalls,offshorebreakers,andrevetments. It isabouttimewechangethisparadigm.Weneedtofirstprotectnaturewhichinturnwillprotectourcommunitiesandfamilies.Thereisastrongneedtoprotectourecosystems.Restoreourwetlands,forestandourmarinereefs.Weshouldnotdisturbourcoastalprocesses,andavoiddisturbingthenaturalhydrologicalcycle.

Somemeaningfulexamplesthatwemaytakeonboardareprotectingourreefs,andplantingofmangroves.

2.1.3AdoptAdaptiveResponsestrategies:retreat,accommodateorprotectionap-proach

Therearethreemaintypesofadaptationresponsestrategiesthatcanbeconsideredforreducingcoastalerosion,protectionofhumanlifeandecosystems–retreat,accommodateorprotect.Inaretreatapproach,coastalsys-temsprocesseswillremainundisturbed.Coastsdynamicwillcontinueasbusinessasusual.People,infrastructureandhabitatsmayhavetomoveinlandorrelocatetohighergrounds.Inanaccommodateapproach,againcoastsdynamicscontinueasbusinessasusualwhilelandusewillbechanged.Usingaprotectapproach,protectionop-tionsareidentifiedwhichmaybeintheformofsoftorhardengineeringstrategies.

“Retreat involves no effort to protect the land from the sea. The coastal zone is abandoned and ecosystems shift landward. This choice can be motivated by excessive economic or environmental impacts of protection. In the extreme case, an entire area may be abandoned. Accommodation implies that people continue to use the land at risk but do not attempt to prevent the land from being flooded. This option includes erecting emergency flood shelters, elevating buildings on piles, converting agriculture to fish farming, or growing flood- or salt-tolerant crops. Protection involves hard structures such as seawalls and dikes, as well as soft solutions such as dunes and vegetation, to protect the land from the sea so that existing land uses can continue.” 38

37MurrayFordandConsultantsNZLtd(2003)38GilbertandVellinger(1990)

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Figure 7: Retreat, Accommodate and Protect strategies (Taken from Dorst in Robbert (ed) (2011)

2.1.4ConductanEnvironmentalImpactAssessment

TheEnvironmentalImpactAssessment(EIA)is“an acti vity designed to identi fy and predict the impact of a project on bio-geo-physio-chemical environment and human health so as to recommend appropriate legislati ve measures, program and operati onal procedures to minimize the impacts.” 39

PacificcommunitiesshouldmakeitapracticetofirstconductanEIAbeforeimplementingacoastalprotectionintervention;theyshouldconductanEIAfirst.TheresultoftheEIAwillhelpformulatestrategiesthatminimizedamagestotheenvironment.AnEIA isusuallyconductedbeforeanyproject is implemented.Thiswillensurethatwewillbeabletodetectorforecastanyharmtotheenvironment.ThegoodthingaboutanEIAisthatitalsoconsidersotherpossiblealternatives.

39AnjaneyuluandManickam(2007)

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2.1.5EnforceForeshoreRegulations

Oneseriousfactorcausingforeshoreerosionisbeachmining.Sandandaggregateontheforeshorearepositionedinsuchawaytoprotectthelandfromforcesofnature.Ifwecontinuetoremovethemwearecontributingtoexposinglandtoforcesofwindandwaves.Thebestthingtodoistocontrolthecontinuousextractionsofmateri-alsfromtheforeshoreaswellasintheinter-tidalzoneandontheseabed.Theimportantstrategyistodevelopaconstructiveforeshorelawthattakesintoaccountmanagementandcontrolofforeshoreandcoastalzone.

“sand extraction through beach mining for construction and reclamation purposes often results in long term depletion of sand resources on beaches and significantly reduces the natural protection that beaches provide.” 40

2.1.6AdoptMarineProtectedAreas(MPAsorMMA)

MarineProtectedAreas(MPAs)orMarineManagedAreas(MMAs)whetherlegalortraditionalareinitiativescre-atedasno-takezones.Theseapproachesarehelpfulinstabilizingandprotectingcoastlines.Theminingofsandandaggregateinanygivencoastalareaexposesthatcommunitytobeacherosion.Byprohibitingtheuseofaparticularspothelpsinprotectingthecoralreefsandseagrassesfromdamage.MPAsorMMAsareimportantinenhancingecosystemswithinthearea.AlmostallPICTshaveMMAsasdepictedintable2below:

Table 2 Comparison of Marine Managed Areas in the Pacific region. Source: Extracted from Govan et al. (2009). Status and potential of locally managed marine areas in the South Pacific.

40Gillie(1997)

PICTs MMA MMA Area (Km2) Active MMAAmerican Samoa 19 174 0Cook Islands 39 19 24Fiji 246 10,880 217FSM 12 23 0Guam 11 170 0Kiribati 15 411,304 0RMI 1 701 0New Caledonia 0 0 0Niue 3 31 0Northern Marianas Is. 8 13 0Nauru 0 0 0Palau 28 1126 0PNG 166 3764 80French Polynesia 10 2837 0Samoa 84 209 54Solomon Islands 127 1381 113Tokelau 3 1 0Tonga 18 10,009 6Tuvalu 10 76 4Vanuatu 55 89 20Wallis & Futuna 0 0 0Timor Leste N/A N/A N/A

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OneofthegreatestachievementsinthePacificwasthedevelopmentofMMAs.Theselocallymanagedareaswereimplementedovermorethan500communitiesandcovermorethan15PICTs.InTable2,Kiribati’smarineman-agedareasisthebiggestinthePacificwith411,304km2whileTongarankedsecondwith10,009km2.FijihasthehighestnumbersofMMAswith246,followedbyPNGwith166andSolomonIslandswith127.FijihasthehighestnumbersofactiveMMAswith217andSolomonIslandshave113activeMMAs.

Theimportanceofestablishing locallymanagedmarineareas isbasicallybecauseoftheirsocial,cultural,eco-nomicandecologicalbenefitsforthosecommunities.Theirmajorcontributingfactorstowardscoastalprotectionarebasedontheconservationofthefirstandsecondlineofdefenseoftheislandfromoceanwavesandextremecycloneandstorms.Undisturbedcoralandseagrassecosystemsactasbufferzonesreducingtheincidentwaveenergy.

2.1.7AdoptNationalBiodiversityStrategyandActionPlan(NBSAP)

NBSAPisanactionplandevisedtoeffectivelyconserveandsafeguardtheover-extractionofbiodiversityandeco-systemswhichhumanpopulationsrelyonfortheirlivelihood.Thestrategieshelpincontrollingtheuseofresourcesandminimizethedisturbancesofcrucialecosystems.TheConventiononBiologicalDiversity(CBD)demandsthateachcountrydevelopaNBSAP.Thesearenationalstrategies,plansorprogrammestoconserveandsustainablyusebiologicaldiversity.NBSAPgivesopportunitiestoprotectandconserveimportantecosystemssuchascoral,seagrass,algalandseaweedthatareimportantnaturallinesofdefense.Protectionofland-basedvegetationisapartoftheconservationmeasures.PacificcountriesthathaveproducedtheirNBSAPareCookIslands,Fiji,Kiribati,MarshallIslands,Micronesia(FSM),Nauru,Niue,PNG,Samoa,SolomonIslands,Tonga,TimorLeste,TuvaluandVanuatu.ThethreemostimportantaspectsofCBDare(1)theconservationofbiologicaldiversity;(2)thesustain-ableuseofbiologicaldiversityand(3)thesharingofbenefitsarisingfromconservingbiologicaldiversity.HavingaNBSAPgivestheopportunityforengagingstakeholders,assessingvitalecosystems,mappingecosystemservicesandidentifyingeconomicservicesindicators.SomegoodpracticelessonsderivedfromNBSAParethecreationofcleargovernancestructure,thereisagoodcommonunderstandingamongstthekeystakeholders,morefocusandastrategicplan,acombinationoftopdownandbottomupapproach,andtheuseoftraditionalknowledge.ThePacifichasarichanddiversebiologicaldiversity.MostofthePacificcountriesNBSAPprovidestrategiestoprotectmarineandterrestrialecosystems,naturalresourcesandendangeredspecies.

2.1.8AdoptanIntegratedCoastalZoneManagementApproach(ICZM)

WhatdowemeanbyanIntegratedCoastalZoneManagement(ICZM)?It is“acomprehensive,multi-sectoral,integratedapproachtotheplanningandmanagementofcoastalareas.Itincludestheprocessofplanningandmanagementforsustainabledevelopment,multipleuseandconservationofcoastalareas.”41

NoonewilldenythecriticalimportanceofcoastalenvironmentsinthePacificregion.RamBidesietal.(2011)arguedthat: “Healthy marine and coastal environments are fundamental to the long term sustainability of island societies, as well as providing the basis for their livelihoods and economic development.”

ThefundamentalchallengesfacingPacificcountriesarethatthesehealthycoastsarequicklybecomingoverex-ploited,ecologicallydegradedandwill likelybecomeunsustainable in thenear future.Awordofadvice is to‘adoptanintegratedcoastalzonemanagementapproach’tosafeguardcoastalresourcesandmaintainlifesup-portingsystemsincoastalareas.RamBidesietal.(2011)hasalsosummarizedthevariousthreatsaffectingPacificCoasts.MostcoastsinthePacificareexperiencingadeclineincoastalresources.Thisisattributedtopollution.Thecompetingusesfordevelopmentpurposesandclimatechangeareamongstthemajorthreats.Overfishing,destroyinghabitats,invasivespeciesandmultiplestressorsaresomeoftheimportantthreats.42

41SOPAC(1994)42RamBidesietal.(2011)

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IfweareplanningforadaptationmeasuresitisalwayswisetotakeintoaccountEcologicallySustainableDevelop-ment(ESD)andICZMframework.Theideaofthisintegrationistoprovideaframeworkthatcombinestheman-agementofbroaddrivers,interrelationships,andeffectsofecological,socialandeconomicforcesandinteractionswiththeeconomy.43

SOPAC(1994)alsorecommendedthatPacificcountriesadopttheintegratedcoastalzonemanagementapproachasaplanningandmanagementtoolforcoastalprotection.

“The goals for Integrated Coastal Zone Management for the Pacific should:

• Sustain natural systems by ensuring sustainability of coastal resources, protecting critical systems, and recognizing the inter-relationships between natural, social, economic and cultural systems. • Be determined by locally identified needs and be appropriate to local social, cultural, political and economic systems. • Balance local, provincial, regional and national goals. • Provide for economic and social needs and aspirations of communities. • Encourage integrated coastal management and strategies at appropriate levels of decision making. • Incorporate measures for capacity building, including training and education at all levels, strengthening institutional capacity, improving information and data bases, and improving the exchange of information, experience and expertise.” (SOPAC, 1994).

Cummingsetal.(2012)recommendedaswelltheadoptionofanESDandICZMframeworktoo.ThecasestudyintroducedbyPostandLundin(1996)onGuidelinesforCoastalZoneManagementinsmallislandstatesisworthtakingonboard.Itprovidesaguideonintegratingcoastalzonemanagementprinciples.PacificcountriesareexpectedtodesigntheirownICZMframeworksthatsuittheirneeds.ThemainobjectivesofICZMarethreefold:

• Reinforcing coastal management through training, legislation and building human resources capacity • Conserving and protecting biological diversity of coastal zone ecosystems • Promoting rational development and promote sustainable uses of coastal resources

ThemaincharacteristicsofICZMare:

• Move away from traditional approaches of managing single factor but promote a whole sector approach • Promotes the analysis of priorities, trade-offs, problems and solutions • Continues managing the use, development and protections of coastal resources • Uses multi-disciplinary approach • Maintain the balance between protecting valuable ecosystems and the development of the economy • Operate within the coastal zones as prescribed by law • Seeks stakeholders input in coastal management • Seeks solutions to various complex issues • Integrate sectoral and environmental needs • Provide conflict management • Promote awareness at all level. 44

43ibid44PostandLundin(1996)

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ThetheoryofICZMwasraisedinthe1970sasa“dynamicprocessinwhichacoordinatedstrategyisdevelopedand implemented for theallocationofenvironmental, socioculturaland institutional resources toachieve theconservationandsustainablemultipleuseofthecoastalzone”45.

TheICZMprincipleandconceptarealsosupportedbyKay(2005).

TheimportanceofICZMisthreefold.1.-developanunderstandingofsystemsandprocesses;2-usingknowledgetoenhancesustainablelongtermenvironmentallyacceptableplansand3-implementingandenforcingaswellaseducatingthepeople.

“ICZM is widely recognized and promoted as the most appropriate process to deal with climate change, sea-level rise and other current and long-term coastal challenges”. 46

Thethreecoastalzonemanagementprinciplesare:

1.Avoiddevelopmentinareasthatarevulnerabletoinundation 2.Ensurethatcriticalnaturalsystemscontinuetofunctionand 3.Protecthumanlives,essentialproperties,andeconomicactivitiesagainstthe ravagesoftheseas47

2.1.9Adopt‘RidgetoReef’approach

The‘ridgetoreef’conceptwasdevelopedasacomponentofthewiderIntegratedWaterResourcesManagement(IWRM)framework.Themajorideaistounderstandhowhumanactivitiesthatdotakeplaceatwatersourcesinthe‘ridge’area(in-landorhigheraltitude)playacrucialroleindegradingthewatershedorcatchmentatthe‘reef’areacausingdamagestomarinelifeandcoralecosystems.Basicallytheridgetoreefapproachisaholisticappreciationofahigh islandecosystemwhereallbiomesand their interactionsare considered. For instance,somethinghappeninguphill(theridge)willeventuallyaffectsomethingdownstream(thereef).Atypicalexampleisdeforestationofagricultureinthehillsthatinputsedimentloadsintoriversthateventuallymakeittothelagoonandchokecoralsandotherorganisms,reducingreefproductivity. Itisveryimportantforcommunitiestounderstandthisconcept,whichtraditionally,Polynesiansusedtopractice.Sometimestheywonderwhytheirlagoonsarelessproductivebutdonotrealizethatitisthroughtheirownde-structionofcoastalwetlandsandalpineforests,uphillanimalhusbandry,poorfarmingpractices,excessiveusesoffertilizersetc.Ahealthyrainforestandwatershedequalsahealthylagoonandreefsystem.(N’Yeurt,2014.pers.com.)

TheimportanceofridgetoreefapproachissimilartoeffortsundertakeninsimilarframeworkssuchasICZM,IntegratedCatchmentManagement(ICM),theIntegratedWatershedManagement,theCommunityBasedEco-systemApproachandtheNationalBiodiversityStrategyandActionPlan(NBSAP).Alloftheseframeworksensurethatecosystemsandbiodiversityareconservedandprotected.

45FarhanandLin(2010)46Nichollsetal.(2007)47GilbertandVerllinger(1990)

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2.1.10Settingengineeringstandards,takingresponsibilities andcomplyingwithcodesofethics

TheguidelinesproposedinCummingsetal.(2012)isinstrumentalintakingtheleadrolewithinthePacificre-gion.IthasbecomeamodelforPacificcountriesbysettingagoodexample.WhiletheguidelinewasspecificallytargetedatAustralianengineerspracticingcoastalengineeringwork,itisequallyrelevantforPacificcountriestoconsider.Beforeacountrythinksaboutputtinginplaceacoastalprotectionintervention,theessenceoftakingfullresponsibilityforyouractions,andcomplyingwithbestinternationalengineeringstandardsandcodeofethicsarecrucial.AustraliahasinplaceacodeofethicsforpracticingengineersandasustainablecharterandacoastalzonepolicywhichcouldformthebasisofadoptionbymostPacificcountries,whichlackthesevitalinstruments.

Manywillwonderwhyitisimportanttocomplywiththeseframeworks.Firstandforemost,theseinstrumentsmayberegardedasdisasterriskreductionmeasures.Itisworthinvestingintheseinstrumentstoavoidpayingtheexpensivecostofecologicalandenvironmentaldamagecausedbyunprofessionalbehavior.Donors,communitiesandinmostcasespoliticalpressureoftenleadtothesetypesofunprofessionalbehaviorintheregion.ThelessongivenbyCummingsetal.(2012)wastoestablishanadaptationdecisionframeworkusingbothlocalknowledgeandscientificknowledge.Thefollowingcoastalmanagementprocesswasoffered:

•Step1-conductliteraturereview •Step2-assessandunderstandcoastalprocesses •Step3-definepastandcurrenthazards •Step4-conductriskassessment •Step5-evaluateallfeasibleoptions •Step6-developmanagementstrategyplan •Step7-adoptmanagementplan •Step8-implementmanagementplan •Step9-conductmonitoringandevaluation48

Settingstandardsisamustinordertoreapthebenefits.Somecountrieshaveanengineeringcouncilthatsetstheseengineeringstandards.EngineeringTechnicianshavetoberegisteredsothattheycarryoutdueresponsi-bilitieswithduecareandobservetheapprovedcodeofconducts.PacificcountriescouldtapUK-SPECasaguideinsettingthesestandards.49Themainfeaturesof‘codeofethics’enablescoastalpractitionersto“demonstrateintegrity,practicecompetently,exerciseleadershipandpromotesustainability.”50Codeofethicsaredesignedinsuchawaythatindividualsandorganizationsfollowsomeformofrulesthatleadstohonesty,integrityandprofes-sionalism.Coastalpractitionersshouldupholdtheprincipleof‘dutyofcare’atalltimesasthisispromotedunderthelawofnegligence.51

Planningforfuturecoastalprotectioninterventionsmustbebasedonasoundunderstandingofcoastalprocessesandfactorsaffectingthecoastalenvironment.52

Humanactivitieswithinthecoastalenvironmentoftenleadtodamagesofecologicalsystemsinthoseareas.ThisiswhyitisusefultodevelopandimplementtheconceptofEcologicalSustainableDevelopment.Theprimeobjec-tiveofESDistoensurethatdevelopmentssafeguardthewelfareoffuturegeneration,protectbiologicaldiversityandmaintainfundamentalecologicalprocessesandlifesupportmechanisms.53ItisalsocommonamongPacificcountriestoconductcomprehensiveEnvironmentalImpactAssessment(EIA)foranyfuturecoastalinterventions.

48Cummingsetal.(2012)49http://www.engc.org.uk/ecukdocuments/internet/document%20library/UK-SPEC.pdf

50 ibid51 Cummingsetal.(2012)

52 ibidp.553ibidp.6

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2.1.11AdoptaproperBuildingCode

Thepurposeofhavingabuildingcodeistoprotectthelife,healthandsafetyofindividualswhowillbeoccupyingthebuildings

“The purpose of various Building Codes is to provide minimum standards to safeguard life or limb, health, property, and public welfare by regulating and controlling the design, construction, quality of materials, use and occupancy, location and maintenance of all buildings, structures and certain equipment within this jurisdiction.” 54

Pacificcommunitieswouldbenefittremendouslyiftheyputinplaceabuildingcode.Infrastructurewouldmeetsomeformofminimumstandards.

Table3:ComparisonofbenefitsandlimitationsofCoastalframeworks

Framework Benefits LimitationsUndisturbedCoastalprocesses •Cheap

•Resourcesareaccessible•Easytouselocalcapacity

•Erosioncontinues•Infrastructureatrisks•Seaovertopping•Seadamagingvegetation

WorkingwithNaturepolicy •Cheap•Useoflocalresources•Withinlocalcapacity

•Requireregularmaintenance•Lackofcommunityinterest

Retreat,AccommodateandProtectpolicy

•Easytoimplement•Benefitcommunity

•Lackofinterest

EIA •Avoidenvironmentaleffect•Minimizedenvironmentaleffectatearlystage•Involveallstakeholders

•Costly•Delaysprojectimplementation•Capacitymaybeabsent

ForeshoreRegulation •Protectandenhancenaturalenvironmentandculturalvaluesofthecoastalzone•Minimizedamagedtothecoast•Providesafeforeshoreenvironment•Infrastructuredonotposedamagetocoastalarea•Providessustainableuseoftheforeshore

•Poorenforcement•Lawbreakerscontinuemining

LMMA/MPA •Increasestockabundance•Preservespawningtimes•Providespilloverofjuvenilefish•Reduceoverfishing

Poorenforcement

54TakenFromhttp://www.ci.san-ramon.ca.us/codeforce/bldcodes.html

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•Ecosystemmanagement•Maintaincoastalprocesses•Providecoastalprotection

NBSAP •Protectbiodiversityloss•Reformoflandtenure•Changeinownershipusersright•Equitablesharingofresources•Biodiversitymanagement

Poorenforcement

ICZM •Preservenatureandresourceforfuturegeneration•Ithelpspreservingandpromotingsocialequity•Helpsprotectingtraditional•Usesandrights•Promoteequitableaccessofcoastalresources•Pro-activeplanningsavesmoney•Promotessustainabledevelopment

•Poorenforcement•Lackofpoliticalwill•Lackofcommunityinterest

ComplyingwithEngineeringstandards

•Qualitydesignsareadopted•Communitysafety•Communityreceivetopqualityadvice•Fundsarenotwasted

•Veryfewprofessionalsaround•Toomanyamateurprofessionals•Absentofengineeringstandardslaws/policy

Buildingcodes •Providessafetymeasurespreventionisbetterthancure)•Reducingtherisks•Preventinjuriesanddeath•Structureswithstandstorm

•Costofcomplyingmaybeaproblem•Weakenforcement

Table 3 Comparison of coastal protection frameworks

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Table 4 Comparison of PICTs with or without coastal protection frameworks

Key:

Countryhasframeworkinplace Countryhasnoframeworkinplace Noclue

InTable4,Tonga,Samoa,PNG,andCookIslandsarealreadywayaheadofothersofhavingthesebasiccoastalmanagementinstrumentsinplace.Fiji,KiribatiandTimorLestearealsoheadingintherightdirection.

Table4:ComparisonofPICTshavingbasiccoastalprotectionframeworks

PICTs EngineeringStandards/Codeofethics

ICZMPlan

LMMA/MPA

BuildingCodes

EIA ForeshoreRegulation

CoralProtection

AmericanSamoaCookIslandsKiribatiFijiFSMGuamNewCaledoniaNiueNorthernMarianasRepublicofMarshallPalauPNGPitcairnIslandNauruSamoaSolomonIslandsTokelauTongaTuvaluVanuatuWallisFutunaTimorLesteFrenchPolynesia


3.1 Introduction

TherearemanyexamplesofstructuralengineeringinterventionsthathavebeenimplementedinthePacificre-gion.Thischapterwillsharesomeoftheexperiencesofgoodpracticesofprovidingeffectivecoastalprotectionsthatareofstructuralapproach.Coastalstructurescanbe in the formofman-made interventionsornaturallyformed.Inthischapterwewillidentifytwosetsofengineeringstructures;thosethatarereferredas‘softmea-sures’,andthosethatareknownas‘hardstructures’.

3.1.1 StructuralEngineeringOptions:

3.2 Softstructuralengineeringoptions:

Softstructuralengineeringoptionsareinterventionsthatmaintainandstrengthenthenaturalformofthecoast-line.Inthisconnection,theadoptionofecologicalprinciplesandpracticestoreduceerosionandachievestabiliza-tionandsafetyofshorelinesarepreferred.Softengineeringmethodsworkbestwhenworkinginharmonywithnature.Theyalsoprotecthabitats,improveaestheticsandarecheaptoconstruct.Naturalmaterialsarenormallyused,suchascoral,sandandvegetation.Weshalllookatnaturalsoftengineeringstructuresfirst.

3.2.1 NaturalSoftEngineeringStructures:

Naturehasconstructedvitalcoastalandmarineresourcessuchasmangroves,coralreefs,seagrassbedsandalgalforestandbedswhichprovideproductiveanddiversemarineecosystems.Theseecosystemsprovidevitalhabi-tats,feedinggrounds,andnurseriesformanymarinespecies.Theseresourcesalsoplayausefulroleinprovidingnaturalprotectionasafirstlineofdefense.

Chapter 3: structural optionsbyLukePaeniu,AntoineDeRamonN’Yeurt,KerrynChungandNicholasHobgood


“The shallow ecosystems and productivity of mangroves, seagrass beds, coral reefs and inter – reefs seabeds are critical natural assets for food production, food security, cultural and recreational activities and livelihoods for many Pacific Islands States. They also provide important ecosystems services in protection of coasts against storm surges and in production of carbonate sands and debris to nourish beaches and maintain islands.” 55

3.2.1.1Maintaininghealthyreefislandsandislets

Pacificcoastscanbestbeprotectedbyhavinghealthycoralreefs.Lowlyingislandsareformedfromcoralcaysmadeupoflimestoneskeletonsofcorals,corallinealgae,andothershallowmarinelife.56Fujita(2009)statesthatreefislandsarenormallyformedoverreefflatsofatolls.Theseislandsarelowlying,flatandsmall.Becauseoftheirsmallsizeandisolation,theyarealsoveryvulnerabletotheeffectsofover-populationandclimatechange.Severeweathereventssuchastropicalcyclonesandnaturaldisasters likeearthquakesandtsunamiscanhavedisastrousimpacts,totallyredistributingthesedimentsandchangingtheprofile,evenlocation,ofthereefisland.

ForverysmallreefislandsnationslikeTuvaluandKiribati,itisextremelyimportanttomaintainahealthyreefeco-systemtoavoidissuesofeutrophicationofthelagoon,overgrowthofcoralreefsbyalgae,lossoffishinggrounds,andcontaminationofthefreshwaterlens.Evenso,theseislandsarethreatenedbysea-levelriseduetoglobalwarming,whichpollutesthe little-availablesoilandfreshwatersupplywithsaltwater intrusion.Kingtidesandstormsfurtheraddtothesaltwaterloadonthefragileterrestrialecosystem.

Oneofthebiggestconcernsonsuchsmallreefislandsistheproperdisposalofwastes,especiallysewage(bothhumanandfromanimals)anddomesticeffluents.Thehighloadsofnitratesandphosphatesintheseeffluents,whicheventuallyallpercolatethroughtheporousatollsandysoilandendupinthelagoon,havedisastrouseffectsontheshallowwatertableoftheatolls,andtheircoastalenvironment.Themostconspicuousmanifestationofsuchpollutionisusuallytheappearanceofalgalblooms,whichcantaketheformofmicro-ormacro-algalprolif-erations(forinstanceinvasiveSargassumspp.whichhasbecomeagreatprobleminFunafuti,Tuvalufollowingadroughtin2011).Thesynergyofweathereventslikedroughtsandanthropogenicfactorssuchasthedirectdump-ingofsewageintothelagoonsanduseoftheseaforcleaningandwashingfurtherexacerbatestheissue.OceanacidificationasaresultofhigherCO2loadsintheatmospherestemmingfromtheburningoffossilfuelsthreatentofragilizethecalcifiedalgalridgesofatollcoralreefs,makingshorelinesmorevulnerabletowavesurges,tsuna-misandcoastalerosion.

Themainthingtorememberinthissituationisthatanythingthatisdoneonland(beittheimproperdisposalofwastesorsewage,theover-useofchemicalfertilizers,theburningoffossilfuels)willsoonshowupinthemarineenvironment,andnegatively impactthelagoonandcoralreefswhichultimatelysustainandmaintainthereefislandandthelifethatdwellsonit,bothbiologicallyandgeologically.Propermanagementpracticesneedtobelearnedandimplementedbylocalcommunities,suchassustainableenergysources(biofuel,photovoltaics),recy-clingofwastes(mulching,composting)andtheavoidanceoftheuseofnon-degradablechemicalsandfertilizers.

55 Kenchington(2009)56ibidp.1

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Figure 8: Left : Example of a polluted coastal environment in Fongafale, Funafuti , Tuvalu leading to a brown belt of Sargassum seaweed facing populated areas. Right: Schemati c of how anthropogenic effl uents enter the lagoon of a reef island, leading to algal blooms and reduced producti vity (Source: Funafuti Master Plan htt p://bluesquid.net/Funafuti %20Masterplan.html)

3.2.1.2Improveseagrassandalgal/seaweedecosystems

Seagrassesareanimportantpartofmarineecosystems.57Theyarehigherfloweringplantswhichhavere-adaptedtogrowsubmergedinshallowmarinewaters.Seagrassesareimportantasasourceoffoodformarineorganismssuchasturtlesandmanateesandprovidehabitatsandnurseryforcountlessinvertebratesandvertebratespecies.58 Theycontributegreatlytotheprimaryproductivityofcoastalecosystems,andtheirrootswhichgrowverticallyaswellashorizontallyhelpwithstand thestrongenergyofwavesandcurrents.Apart fromtheir functionsofstabilizingthecoastalseabeds,seagrassesalsotrapsedimentsandfilternutrientsthatflowdownfromtheland,effectivelyactingasasedimentbarrierthatprotectsandbuffersthecoralreefsfrombeingoverwhelmedbypar-ticulatemattersfromtheland.Removingseagrassesfromcoastalareaswouldcontributetothedestabilizationofthecoastalzoneanddegradationofthecoastalmarineecosystem.SoitiswisetomaintainseagrassesasanaturalformofstabilizingthePacificCoasts.SeagrassesarepresentinalmostalltheislandsofMicronesiaandMelanesia,Kiribati,WallisandFutuna,WesternSamoaandNiuebutareabsentintheregionsofTuvaluandTokelau,Phoenix,andtheCookislands.AsinglespeciesoccursintheSocietygroupofFrenchPolynesia;normallyaswegofurtherWest,morespeciesarefound,forinstance1speciesinRotuma,3speciesinWallis,5inFiji,10intheSolomonIslands.59

InmanyPacificIslandssuchasFiji,theimportanceofseagrassareasareoverlooked,andtheyareoftenthevictimsofcoastaldevelopmentandpollution.Beingnotasvisibleasmangroves,theirroleinthemarineecosystemisnotasoftenwellunderstoodbythelocalcommunities.Furthermore,theremovalthroughcommercialfishingofotherorganismsusuallyassociatedwithseagrassbeds(e.g. holothurianssuchsuchasBêche-de-mer,Holothuria atra) further contributes to the lossofproductivityof coastalecosystems in theregion.

57 Takenfromhttp://myfwc.com/research/habitat/seagrasses/information/importance/58 ibid

59 Shortetal.(2001)

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Figure 9: Left : The seagrass Syringodiumisoetifolium, the only one found in Rotuma Island, Fiji. Middle: Halophilaovalis, a common seagrass species on the Suva foreshore area in Fiji (credit: SeagrassWatch). Right: Extensive seagrass beds of Haloduleuninervis in Naselese, Taveuni, Fiji.

Aproperapproachtotheprotectionofseagrassecosystemscouldstartatthecommunitylevel,byraisingtheawarenessoftheimportanceofthesemarinecommunitiestotheoverallproductivityofthereef,onwhichcoastalcommunitieshighlydependforlivelihood.Havingahealthyseagrassecosystemwillinturncontributetoahealthyandstructurallystrongcoralreefecosystem,reinforcingthecoastalprotectionofPacificshorelines.

3.2.1.3Maintainhealthyfringingandbarriercoralreefs

Coralreefshelpinprotectingtheislandfromwavesandtsunami.Coralreefsarenormallyfoundinwarmtropicalandsub-tropicalwaters.MostofthecoralreefsarefoundinthePacificOceanwhilesomearefoundinIndian,CaribbeanandAtlanticOcean.Coralreefdevelopmentfallswithinthe200CisothermlimitswheremostofPacificIslandsarelocated.60Coralreefsecosystemsgrowbestinlow-nutrient,shallowwaters.AccordingtoYamamotoandEsteban(2011),coralreefsareformedfrommicroscopicalgaeandskeletalstructuresofcalciumcarbonate.

“Coral reefs are characterized by a high level of biodiversity and elaborate specializati on of resident species, and provide many ecosystem services that economically support nearby human populati ons. They also off er some level of protecti on from natural disasters such as waves or tsunamis.” 61

Reefhealthisacombinationoffactors,andisintimatelylinkedtothehealthoftheecosystemsoftheentireislandthatthereefssurround(“ReeftoRidge”concept,launchedbytheIUCNin2010).

60SPREP2001.Island Ecosystems: Pacifi c Region61YamamotoandEsteban(2011)p.5

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Figure 10: Left : A healthy island refl ects into a healthy reef system. Right: The Reef to Ridge Concept.(Source: Left -Wikipedia Commons; Right-Micronesia Conservati on Trust).

Inordertoensurethatreefsarehealthy,land-basedinfluenceneedstobekepttoaminimum.Uncheckeddefor-estationforfirewoodandcommercialtimberexploitationonthehillsofhighislandswillleadtoheavysedimentloadsintowatercatchmentsleadingintothelagoon,carryingparticulatematterthatcansmotherfragilecoralpol-yps.Likewise,theexcessiveuseoffertilizersonfarmlandslocatedonriverbankswillleachchemicalcompoundssuchasnitratesandphosphatesintothewaterways;tourismdevelopmentssuchasgolfcoursesalsoleachlotsof fertilizers into thewater table. Eventually all of thesenutrientswill accumulate into coastal areas, causingeutrophicationandalgalblooms.Heavysedimentationwillalsokillseagrassbedsandseverelyharmmangroveshabitats,withtheuncheckedfinesoilparticlesmakingtheirwaytothecoralreefsandharmingthereef-buildingpolypswhichplaysuchanimportantroleinprotectingshorelinesfromincomingwaveenergy.

3.2.1.4PlantingMangroves

Mangrovesareformsofnaturaltropicalcoastalvegetationthatareadaptedtogrowwellundersalineconditions.Protectingmangroveshelpinprotectingthecoast.Mangrovescanreducetheimpactofwaveerosionbytrappingsand.Theyalsohelpinextendingthecoastlineasthemangrovesgrowandextend.Theyhavelongcurvedrootsthatpropsupfromtheground;theserootshelp intrappingsedimentsandsandandreducescoastalerosion.MangrovediversityisgreatestintheWesternIndo-Pacific,withFijiforinstancehavingthethirdlargestmangroveareainthePacificwith517km2andeightdifferentspecies.Theygrowextensivelyonsedimentaryshorelinessuchasdeltas,andhaveveryhighsedimentaccretionratesandsub-surfacecarbonstoragecapabilities.62AswegoEastintothePacificmangrovespeciesdiversitygetsless,andtheyarenaturallyabsentfromeasternPolynesiaalthoughafewintroducedstandsexistinBoraBoraandTahiti(N’Yeurt,pers.obs.).Inadditiontotheirroleassedimentandcarbontraps,mangrovesofferaveryeffectivenurseryareasforthelarvaeandjuvenilesoffishandcountlessothermarineorganisms,playingaveryimportantroleintherestockingofnearshoreislandfisheries.Manyfoodspeciessuchasoystersandclamshellsgrowonmangroveroots,andaretraditionallyharvestedforsubsistencepurposesbylocalcommunities,whoalsodependonmangroveecosystemsforfishingandfirewood.

Whilerisingsea-levelswillhavesomeimpactonthesurvivalofcoastalmangroves(especiallyonhighislandswith-outriversystemsandlitt lesedimentaryareas),thegreatestimminentthreattotheseecosystemsisfromhumanactivity.CoastaldevelopmenthasclearedvastareasofmangroveforestsfromPacificIslandcountriesbeforeregu-latorymeasureswereinplace,andevennowthereismuchillegalcuttingofmangrovesforthesaleoffirewood,mostlybylow-incomecommunitiesthatdependontheseresourcesforalivelihood.Insomeareas,mangrovesarealsousedasconvenientrubbishdumps.

62Ellison,J.(2010)

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Theroleofmangroveareasincoastalprotectioncannotbeoverlooked;inonestudyfollowingtheAsiantsunamiof2004itwasseenthatcoastalareasimmediatelybehindevenrelativelysmallmangroveareassufferedmini-maldamageandlossoflifecomparedtoareaswithoutanymangroves.63Whilethisfindingwaslaterdisputedbysomeotherresearchersastoonaïve,itisclearthatmangroveareasplayanimportantroleindissipatingandbreakingupwaveenergy,uptoacertainlimit(ofcoursenotforaverylargetsunamiwithwaveshigherthantheheightofthemangrovetrees,forinstance).However,bycombiningseveralwaveenergybreakingsystemssuchasrevetments,mangrovesandrowsofcoastalvegetation,muchofthedamagetotheshorelinecanbeeffectivelymitigated.

BecausesomuchofthecoastalmangroveareasofthePacifichavebeenlosttovariousformsofdevelopmentandhavealsobeencutdownforfirewoodorsimplybecauseofthewrongnotionthattheyare‘unhealthy’andfosterdisease(alegacyofill-informedcolonialeraadministrators),thereisanurgentneedtocarryoutreplantingprojects,preferablyinvolvingentirecommunitiesinthecontextofawarenessexercisesastotheimportanceofmangroveecosystems.SuchreplantinghasalreadybeendoneinislandcountriessuchasFijiandKiribati,althoughtheyhavebeenlesssuccessfulinareaswherewhitesandybeachesarepredominantandsoftsedimentarymudareabsent.

Figure 11: Left : Planti ng mangroves in Tuvalu to protect the shoreline from erosion (Source: Japan Internati onal Cooperati on Agency - JICA). Right: the dense and complex aerial roots of mangroves are very eff ecti ve sediment traps that reduce coastal erosion, and also serve to dissipate wave energy in such events as tsunamis.

Onehastobemindfulwhenplantingjuvenilemangrovesnottoplantinhighenergyzonesandthebestsitesarethosewithlowenergytraffic.Kiribati’srecentmangroveplantingisthebestillustrationwherethesitesatBonrikiandTemaikuwereselected.Thesearesiteswherecurrentsareweakasthelongshoredriftandnormalwindfaceoppositedirections.

63Danielsenetal.(2005)

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Figure 12: Left : These mangrove roots (Rhizophorastylosa) trap sediments at the Nasese foreshore in Suva, Fiji. Right: Exten-sive mangrove areas such as this one in New Caledonia act as nurseries for a wide range or marine organisms (Photo by Joyce Avaemai).

3.2.1.5StabilizingCoastalBeaches

“Sediments of these islands consist of unconsolidated of bioclasti c sands and gravels. Parti cularly, the upper part of subsurface sediments and surface sediments are mainly composed of foraminiferal sands.” 64

Foraminiferalsandsarepartsofreefsands,theyareeitherdisc-shapedorstar-shapedsand.Theseforaminiferasareorganismsfoundincoralreef.AccordingtoFujita(2009):

“foraminiferas are now being recognized as important sand producers for the maintenance of reef islands”.

InTuvalu,theJICA-fundedForamSandProject,thefirstphaseofwhichwasimplementedonthe1stofApril2009andendedonMarch31st2014,hadtheobjective“toincreasetheresilienceoftheTuvalucoastagainstsealevelrisethroughecosystemrehabilitationandregenerationandthroughengineeringsupportforsandproductionandsedimentationprocesses”.Theproject’spurposewastodevelopamodelofthesandproductionandtranspor-tationprocessesintheTuvalulagoon,takingintoaccounthumanactivitiesandglobalwarming.Followingthis,specificeco-engineering techniqueswere tobedeveloped to createand/or restore sandybeacheserodedbycoastalprocesses.Thecapacityandawarenessofthelocalcommunities,fisheriesandGovernmentstaffwasalsoimprovedtoenableconservationofthecoastalenvironmentandecosystems.

64Fujita(2009)

32


Figure 13: Left : The Tuvalu Foram Sand Project. Figure 14: Right: Foraminifera, or ‘star sand’ (Source: htt p:// cdn.physorg.com).

InitialresultsofthefirstphaseoftheForamSandproject,whileveryencouragingintermsoftheabilitytocultureandreproduceforaminifera intheTuvaluenvironment, indicatethatthisbio-engineeringtechnique isstillnotmatureintermsofthecost-effectivenessonalargescale,andfurtherresearchisstillneededtomakeitpracticaltoimplementintheclimate-changethreatenedatollnation(Dr.AkihiroKawada,pers.com.).

3.2.1.6PlantingCoastalVegetation(littoralplants)

Thecoastallittoralvegetationisoftenneglectedbythecommunitiesandcoastalplantsareoftentheveryfirsttoberemovedwithoutassessingtheimportantparttheyplayinstabilizingandprotectingthebeachandcoastline.Coastallittoralvegetationsareshrubs,grasses,plantsandtreesthatgrowadjacenttothecoastalareas.Humanactivitiesnearthecoastsaretheprimereasonsfordamagingandunnecessarilyremovingofthesevegetations.MostPacificcountrieshavetheirownnaturallittoralvegetationsbutinsomecasessimilarplantsarecommoninmostPacificcountries.Thereisastrongsuggestiontogrowandre-plantthesetypesofvegetationforstabilizingthecoasts.

3.2.1.7BeachNourishment

Beachnourishmentisaninterventionusedtorebuildanerodingbeachorlostshorelineortocreateanewshore-line.Materialsaretakenfromadifferentsourceandfilledintheaffectedshorelinetowidenthebeach.Sandissimplyaddedtotheaffectedbeach. It involvesthedepositingofvolumesofsandwithorwithoutsupportingstructurealongtheshorelinetowidentheexistingbeach.

3.3Hardstructuralengineeringoptions

Theapplicationof‘hardengineered’solutionreferstothedesign,constructionandmaintenanceofman-madeengineeredinfrastructuretomitigatethedetrimentalimpactofclimatechangeandprotectionofthenaturalen-vironment.Typicalcoastalprotectionhardengineeringstructuresarebuiltprimarilytopreventtheriskoffurtherscouringalongtheshorelineinordertoprotecttheexistingtopographyandinfrastructure.

TypesofhardengineeredstructurescommonlyusedinthePacificIslandsincludeseawalls,revetments,gabions,Renomattresses,riprap,andbreakwaters.ThecurrentcoastalprotectioninnovationwasthedevelopmentofthegeotextilecontainerssuchastheElcorockproduct(Hornsey,etal.,2011).

33


Whilethehardengineeredsolutionsmayproposea longerdesign lifecomparedtosoftengineeredsolutions,therearemanycriticalfactorsthatcontributetothesustainabilityofeachstructure.Furthermore,thedetaileddesignsolutionwillvarycasebycasetakingintoaccounttheexistingfeaturesoftheareaandtheavailablere-sources.

Therefore,communitiesareadvisedtooutweighthefollowingoptionsaccordinglytoensureadequatecohesionwiththeexistingenvironmenttooptimizeafeasiblesolution.

Table 5: Hard Engineered Solution Alternatives

3.3.1Seawalls

AseawallisthemosteasilyidentifiedhardengineeredstructureinthePacificIslands.Whentheword‘seawall’ismentioned,majorityofthosehearingitimmediatelypictureaverticalconcreteorrockwallalongsidethecoastalembankment.Seawallsareconstructedparalleltotheshoreline,sandwichedbytheexistinglandformorreclama-tionononesidewhileexposedtooceanwavesorrivercurrentsontheother(Cummings,etal.,2012).Likeanystructure,aseawallwillrequirethoroughgeotechnicaltestingandsubsurfaceinvestigationtoassesstheexistingconditionsinordertoproceedwiththedesignaccordingly.Anenvironmentalimpactassessment(EIA)isalsocon-ductedtoensurethatthereisminimaldisturbancetotheexistingecosystemand/orthenaturalfloraandfaunaisenhanced.

Theseawallcategorybranchesoutintodifferenttypesbasedonthetypeofmaterialusedandformationofthestructure.These includeconcretewall,sheetpiling,gabions,andgeotextilecontainersofwhichthetwocom-monlyusedareconcreteandsheetpiling.

Componentsofseawalldesignincludelocationoftheseawall,height,weightofthestructure,structuralconnec-tions,fillmaterial(landwardoftheseawallface),seawallcap,provisionsforsubsoildrainage,andtoeprotection(ODNR,OfficeofCoastalManagement,2011).

a) Concrete seawall –thistypeofstructureisbuiltintwoways.Eitherbydredgingandpouringfreshconcreteonsiteorplacingprecastconcreteblocksandinterlockingtheminsequence.Constructionofthefoundationisthemostcriticalandcomplexcomponentoftheentirestructure.

Concreteseawallsareexpensivetoimplementbutdependingonthedesigntheycansustaintremendousloadcapacityfromwaveconditionsandhavelongerdesignservicelifecomparedtootheralternativematerials.

Table 1: Hard Engineered Solution Alternatives HARD

ENGINEERED SOLUTIONS

Alternatives

Concrete Steel Rock Timber Gabion Reno Mattress

Geo Container

Cat

egor

y

Seawall • • • • Revetment • • • • Groynes • • • • Breakwater • •

34


b) Sheet Piling- thistypeofstructureismadeofsteelsheetswhicharealignedtogethertoformapilewallalongtheembankment.Thesteelsheetsaredriven into thegroundat thedepthrequiredandeach interlockswiththeadjacentsheetaccordingly.Themethodofconstructingthistypeofstructureofferstemporarydetrimentalimpacts to the surrounding communitywhich include noise,medium to high trafficmanagement due to theuseofheavyplantandmachinery(dependingonthelocation),andairquality.Thesefactorshavetobestrictlymonitoredandmitigated.Thedesignofsheetpilemustbeadheredtoduringconstruction,particularly, inthepreparationofthesheetpilestoensureitsadaptionandsuitabilitytothecoastal(saline)environment.Drillingmethodologyandsequenceof formingthesheetpiles isanothercriticalaspectbecause itdirectlyaffects thedesignlifeofthestructure.

Thecriticalfactorsthatneedtobeconsideredinthedesignofseawallsareasfollows:

Table 6: Seawall Components

No. Component Purpose Diagram

1 Toe scour protection

• To prevent undermining of the structure

http://perfectionseawalls.com/build-a-seawall-bulkhead/

2 Material type • To withstand impact of waves or currents

• To ensure sustainability (balance of obtaining optimum design service life and low maintenance)

3 Filter system • To prevent loss or scour of land behind the structure

4 Crest height • To limit wave overtopping which may be damaging to the structure

http://www.stabroeknews.com/2009/archives/12/31/spring-tides-overtop-seawall/

5 Splash apron

6 Land use • Safe use of land directly behind the structure must be adhered.

http://geography.wr.usgs.gov/pugetSound/

Wave Force Absorb

energy

Water cannot seep through Land

Behind Structure

Filter material (geotextile)

35


Table 7: Seawall Alternative Comparison Summary*Ratings shown are indicative only and are subject to final design, availability of materials, and site specific environment conditions.

3.3.2 Revetment

Revetmentstructuresaresimilartoseawalls.Theonlydistinctivecharacteristicisthatunlikeseawalls,whichareverticalinnature,revetmentsareinclinedatamorehorizontalslope.Revetmenttypesincludeconcrete,ripraporrock(armor)revetments,Renomattresses,andgeotextilecontainers.However,thetwomostcommontypesthathavebeenusedarerockrevetmentsandRenomattresses.

Geotechnicaltestingandsubsurfaceinvestigationandpreparationisnotascomplexasthatofseawall.However,environmentalimplicationsremainsimilar.

a) Riprap or rock (armor) revetment–thisstructureisoneofthesimplestformsofcoastalorriverbank protection.Themajorfactorsaresubgradepreparation(withgeotextilefilter),andthesizeand placementoftherocks.Thisisamorenaturalapproachtoreducingdirectimpactofwaveenergy againsttheembankmentandenhancessustainabilityorpotentialgrowthofnaturalfloraandfauna. However,continuousmonitoringandpossibleneedforconstantfutureextensionsmayprovecostlyin thelongterm(Coates,etal.,2000).

Componentsofatypicalrockrevetmentarearmorlayer,filterlayer,toe,crest,andsplashapron (optional)showninFigure1.

Table 1: Seawall Alternative Comparison Summary

SEAWALL

Alternatives

Concrete Steel Gabion Geo Container

Fact

ors

Structural performance

Design Life

Construction Complexity

Implementation Cost

Environmental Rating

High Moderate Low

36


Figure 15: Typical Rock Revetment Secti onSource: (ODNR, Offi ce of Coastal Management, 2011)

b)Reno Matt resses– thisstructureoffers improvedstructuralstabilitycomparedtorock(armor)revetments.Renomattressesaremadeofwireframedmattresseswhicharefilledwithsuitablysizedrocks.Therefore,rocksaremoresusceptibletoremainintactstructurallywiththeboundaryofthewiremattresscomparedtotypicalrockrevetments.Thethicknessofthemattress,whichislessthan0.3m,(Maccaferri,2013)anditsformenablesitsuniquestructuralflexibilitytobeplacedataverticalradiustoformacrestapronatthetopofthestructureandcontinueovertheembankmentslope.

Figure 16: Reno Matt ress Secti on ExampleSource: htt p://www.terraaqua.com/bank-paving.php [Accessed 11 February, 2015]

37


Table 8: Revetment Alternati ve Comparison Summary*Rati ngs shown are indicati ve only and are subject to fi nal design, availability of materials, and site specifi c environment conditi ons.

3.3.3 Groynes

Groynesarestructuresbuiltperpendicular to thecoastline tomanage thecoastalerosionby interrupting thedirectimpactoflongshorewaves.Theimplementationofgroynesisusuallyaccompaniedbybeachnourishment.Thegroynescausesandaccretionontheupdriftshorelineandconcurrentlyreducethesandfeedtothedowndriftareawhichcausestheerosion(Cummings,etal.,2012).Thereduceddowndrifterosionisthenfurthermiti-gatedbybeachnourishment.ThiseffectisshowninFigure3.

Groynesneedtobeplacedinappropriatelocationsinordertomaximizeenvironmentalopportunitiesinreducingthedependencyonsandnourishmentwhichinturnreducestheoveralldisturbanceoftheshoreline(Coates,etal.,2000).

Figure 17: Scheme of interacti on of groynes, waves, currents and shoreSource: htt p://www.coastalwiki.org/w/images/8/84/File1.jpg [Accessed 11 February, 2015]

REVETMENT

Alternatives

Concrete Rock

Reno Mattress Geo Container

Fact

ors


Design Life


Implementation Cost


38


Thetypeofgroyneisdependentonthematerialtype.Forexamples,groynescanbemadeoftimber,concrete,sheetpiles,rocks,gabionbasketsorgeotextilecontainers.Thetypeofgroynetobeuseddependsontheexistingenvironmentalconditionandavailabilityofmaterials.However,themostcommontypeofgroyneconstructedistherockgroyne.

Timbergroynesintheformofhardwoodhavebeeninitiallyused.However,timbergroynesdonotabsorbthewaveenergybutinsteadreflectitwhichmakesittobefarlesseffectivethanthatofrockgroynes.Furthermore,structural failure ismore likely tooccurwithtimbergroynesdue to the scour channels at the seawardends.(Coates,etal.,2000)

Therefore,idealgroynestructuresnormallyincludetheuseoflargerocksorboulders.

a)RockGroynes–thisisacommontypeofgroynewhichhasproveditseffectivenessovertheyearsin termsofabsorbingwaveenergyandstructuralstability.Unlikerockrevetments,rockgroynesuse muchlargersizerockorboulders.Thesizeselectionistoensurestabilityconsideringthepotentialof thewaveimpactespeciallyduringstormsurgesandstructuralsett lementcausedbylargesediment movements.

Figure 18: Rock Groyne ExampleSource: htt p://www.stacey.peak-media.co.uk/EastonBavents/EastontoSizewellDec08/EastontoSizewell08.htm [Accessed 29 January, 2015]

39


Table 9: Groyne Alternati ve Comparison Summary*Rati ngs shown are indicati ve only and are subject to fi nal design, availability of materials, and site specifi c environment conditi ons.

3.3.4Breakwaters

Breakwatersaregenerallydesignedparalleltotheshorelineandinsomecasesattachedtotheshoreline(U.S.ArmyEngineerResearchandDevelopmentCenter,2015)Breakwaterstendtochangethecoastaldynamicsbyreducingtheamountanddirectionofwaveenergydirectlyimpactingthecoastline(Cummings,etal.,2012).

Thestructuraldesigntoolsforbreakwatersaresimilartoseawallsandgroynessuchasthearmortypeandsize,filteringrequirements,toeprotection,andovertopping(Cummings,etal.,2012).RefertoFigures5and6forex-ample.

Figure 19: Conventi onal Multi -Layer Rubble Mound BreakwaterSource: (Cummings, et al., 2012)

GROYNE

Alternatives

Rock Gabion Geo Container Timber

Fact

ors


Design Life


Implementation Cost


High Moderate Low

40


Figure 20: Rock Breakwater ExampleSource: htt p://www.svsarah.com/Sailing/Atlanti cCircle/Images/Angra%20Marina%201.JPG [Accessed 11 February, 2015]

Typically,breakwatersareconstructedinhighwaveenergyenvironmentsandaremadeupoflargearmorrocksorprecastconcreteblocks.Forlowerwaveenergyenvironments,gabionsorgeotextilecontainersmaybeused(U.S.ArmyEngineerResearchandDevelopmentCenter,2015).

Table 10: Breakwater Alternati ve Comparison Summary.

3.3.5 GeotextileContainers(InnovativeSolution)

Traditionalcoastalerosionprotectionsystemhasrevolvedaroundtheuseofrockandconcretewhichwhilestructurallyeffectiveisnotconsideredenvironmentallyoruserfriendly.Thishadthereforeledtothedevelop-mentofinnovativeproductssuchasthegeotextilecontainers(Hornsey,etal.,2011).

BREAKWATER

Alternatives

Concrete Rock Gabion Geo Container

Fact

ors


Design Life


Implementation Cost


41


Geotextilecontainersaremadeupofgeotextilematerialthatisfilledwithsand(orlocallyapprovedmaterial).Afterfilling,thecontainersareclosedbysewingtheopenendwithanindustrialmachineonsiteandthenplacedinlayersaccordingtothedesign.

Thesecontainertypesholdseveraladvantagesoverrockstructureswhichincludeitscosteffectiveness,rapidandreversibleconstructionmethod,provisionofmarinelifehabitat,anditsnaturalaesthetics(Mocke,etal.,2008).

However,theuseofsandfilledcontainershaslimitationswithrespecttothewaveconditionsandisrecommend-edformildorlimitedwaveclimates(Cummings,etal.,2012).Asaresult,therehasbeencontinuousdevelopmentofspecializedmaterials thathavethecapacitytowithstandharshconditionsexperienced inexposedenviron-ments(Hornsey,etal.,2011).

Today,withimprovedgeotextilematerials,thesesandfilledcontainershaveproventheireffectivenessinthevari-ousformsofcoastalprotectionnamely,groynesandrevetments(Figure21andFigure22).TheyhavealsobeenusedasbreakwatersandseawallstructuresinafewcasesasshowninFigures8and10.

Figure 21: Geotexti le Sand-fi lled Container (Elcorock) Groyne ExampleSource: htt p://www.elcorock.com/case-studies/maroochydore-protected-elcorock [Accessed 29 January, 2015]

Figure 22: Geotexti le Sand-fi lled Container (Elcorock) Seawall ExampleSource: htt p://www.elcorock.com/case-studies/maroochydore-protected-elcorock [Accessed 29 January, 2015]

42


Figure 23: Geotexti le Sand-fi lled Container (Elcorock) Revetment ExampleSource: (Hornsey, et al., 2011)

Figure 24: Geotexti le Sand-fi lled Container (Elcorock) Breakwater ExampleSource: (Hornsey, et al., 2011)

43


3.3.1 Table11:HardEngineeredSolutionsOverviewH

ard

Engi

neer

ed S

olu-

tion

sP

hoto

grap

hM

ajor

Com

pone

nts

Wav

e C

ondi

tion

Lim

it 1

Con

stru

ctab

ility

Envi

ronm

enta

l Im

pact

Cos

t Im

plic

atio

n 2

Ref

eren

ces

Con

cret

e Se

awal

l

http

s://

ww

w.fl

ickr

.co

m/p

hoto

s/ra

obha

sk/

sets

/721

5761

9303

6702

68/

page

2/

• M

ade

up c

oncr

ete

and

stee

l rei

nfor

cem

ent

• Th

ickn

ess

and

shap

e of

wal

l dep

ends

on

the

desi

gn w

hich

is s

ubje

ct to

lo

catio

n•

Wal

l thi

ckne

ss le

ss th

an

0.5m

ave

rage

.•

Con

cret

e st

reng

th ra

nges

fro

m 2

0-50

MPa

• D

esig

n lif

e of

50

year

s

• M

ediu

m to

Str

ong

wav

e co

nditi

ons

• C

ompl

exity

leve

l – h

igh

• G

eote

xtile

laye

r is

plac

ed

prio

r to

the

plac

emen

t ste

el•

Dep

th o

f fou

ndat

ion

depe

nds

on s

oil c

ondi

tion

• C

oncr

ete

may

be p

oure

d on

site

or p

re-f

abric

ated

of

f site

and

con

stru

cted

on

site

in s

ectio

ns

• Se

awal

l mat

eria

l sha

ll be

de

sign

ed to

sui

t mar

ine

envi

ronm

ent

Initi

al c

ost –

hig

h

Low

mai

nten

ance

(Roy

al H

asko

n-in

gDH

V, 2

012)

Shee

t pilin

g

http

://w

ww

.asc

eoc.

org/

imag

es/u

ploa

ds/0

30.J

PG

• M

ade

up o

f she

et p

iles

that

are

des

igne

d to

resi

st

corr

osio

n in

con

stan

t exp

o-su

re to

mar

ine

envi

ronm

ent

• Sh

eet p

iles

can

be m

ade

of P

VC, fi

ber

glas

s or

ste

el•

Des

ign

life

50 to

75

year

s

• M

ediu

m to

Str

ong

wav

e co

nditi

ons

• C

ompl

exity

leve

l – h

igh

• Sh

eet p

iles

are

driv

en a

t a

sign

ifi ca

nt d

epth

bel

ow

seaw

ater

leve

l to

ensu

re

stru

ctur

al s

tabi

lity

• D

epth

of s

heet

pile

de-

pend

s on

exi

stin

g gr

ound

co

nditi

ons

• A

nti-c

orro

sion

mea

sure

s su

ch a

s pa

int a

pplic

atio

ns

are

appl

ied

to th

e st

eel

shee

t pile

s.•

Hea

vy m

achi

nery

(pi

le

driv

ers

are

used

) to

driv

e th

e pi

les

in s

eque

nce

whi

ch a

re th

en in

terlo

cked

.

• Se

awal

l mat

eria

l sha

ll be

de

sign

ed to

sui

t mar

ine

envi

ronm

ent

• Sh

ort-

term

env

ironm

enta

l di

stur

banc

e su

ch a

s no

ise

and

dust

to b

e m

itiga

ted

durin

g co

nstr

uctio

n.

Initi

al c

ost –

hig

h

Low

mai

nten

ance

(Am

eric

an

Soci

ety

of

Civ

il En

gine

ers,

20

13)

Roc

k re

vetm

ent

http

://w

ww

.mr-

idea

ham

-st

er.c

om/h

owto

/kay

ak/

imag

es/r

evet

men

t.jpg

• M

ade

up o

f dire

ct p

lace

-m

ent o

f sui

tabl

y si

zed

rock

s•

Roc

k si

ze d

epen

ds o

n w

ave

heig

ht, p

erio

d an

d di

rect

ion

and

slop

e•

Rev

etm

ent c

rest

can

be

str

uctu

re in

to a

pub

lic

wal

kway

• D

esig

n lif

e 3-

5yea

rs

• M

ild w

ave

cond

ition

• C

ompl

exity

leve

l – lo

w

• G

eote

xtile

laye

r is

plac

ed

prio

r to

the

plac

emen

t of

rock

s•

Roc

ks p

lace

d at

incl

ina-

tion

or b

atte

r slo

pe to

m

erge

with

the

exis

ting

land

form

• C

rest

mus

t be

abov

e hi

gh

wat

er m

ark

or la

rges

t pro

-je

cted

sto

rm w

ave

impa

ct

• D

issi

pate

wav

e en

ergy

pr

even

ting

scou

ring

• Ef

fect

iven

ess

may

de

crea

se o

vert

ime

if co

n-tin

ued

fore

shor

e er

osio

n•

Larg

e ro

ck re

vetm

ent c

an

be a

haz

ard

due

to p

oten

-tia

l bu

ildup

of a

lgae

Initi

al c

ost –

med

ium

Med

ium

mai

nten

ance

(Con

tinuo

us e

xten

sion

al

ong

adja

cent

pro

per-

ties

may

be

requ

ired)

(Coa

tes,

et a

l.,

2000

)

44


3.3.1 TableII:HardEngineeredSolutionsOverview

Har

d En

gine

ered

Sol

u-ti

ons

Pho

togr

aph

Maj

or C

ompo

nent

sW

ave

Con

diti

on L

imit

1C

onst

ruct

abili

tyEn

viro

nmen

tal I

mpa

ctC

ost

Impl

icat

ion

2R

efer

ence

s

Ren

o M

attr

esse

s

http

://w

ww

.geo

fab-

rics.

com

.au/

prod

ucts

/pr

oduc

ts/3

6-re

notr

ade-

mat

tres

ses/

over

view

• M

ade

up o

f wire

mat

-tr

esse

s w

hich

are

fi lle

d w

ith s

tone

s•

Thic

knes

s of

mat

tres

s ra

nges

from

0.1

7m to

0.3

m•

Ston

e si

zes

are

80m

m to

15

0mm

• Th

e w

ire b

aske

t has

a

PVC

coa

ting

whi

ch p

ro-

tect

s it

agai

nst c

orro

sion

.•

Des

ign

life

5-10

yea

rs

• M

ild w

ave

cond

ition

• C

ompl

exity

leve

l – m

e-di

um

• G

eote

xtile

laye

r is

plac

ed

prio

r to

the

plac

emen

t of

the

mat

tres

s•

Mat

tres

s is

a fl

ex-

ible

str

uctu

re th

at c

an b

e pl

aced

at a

radi

us to

mer

ge

with

the

exis

ting

land

form

• Su

bgra

de to

be

stab

ilized

pr

ior t

o pl

acem

ent o

f mat

-tr

esse

s.

• St

abiliz

es s

lope

or e

m-

bank

men

t•

Prov

ide

inte

rlock

ing

thro

ugho

ut th

e pr

otec

ted

area

.•

Enab

les

grow

th o

f loc

al

fl ora

and

faun

a

Initi

al c

ost –

med

ium

Low

mai

nten

ance

(Mac

cafe

rri,

2013

)

Gab

ions

http

://w

ww

.fost

ersu

pply

.co

m/P

rodu

cts/

Eros

ionc

on-

trol

/Gab

ionB

aske

ts.a

spx

• M

ade

up o

f wire

bas

kets

w

hich

are

fi lle

d w

ith ro

ck

piec

es.

• R

ock

size

s ar

e 10

0mm

to

200m

m•

The

wire

bas

ket h

as a

PV

C c

oatin

g w

hich

pro

-te

cts

it ag

ains

t cor

rosi

on.

• D

esig

n lif

e 5-

10 y

ears

• M

ild w

ave

cond

ition

• C

ompl

exity

leve

l – m

e-di

um to

hig

h

• St

ruct

ure

is in

clin

ed (

4-10

°) a

s sh

own

in th

e fi g

ure

to e

nhan

ce s

tabi

lity

• B

acki

ng e

arth

(ba

tter

slop

e) m

ust b

e st

abi-

lized

prio

r to

erec

tion

of

stru

ctur

e.•

Gab

ion

bask

ets

stre

tche

d pr

ior t

o fi l

ling

of ro

ck

mat

eria

ls.

• Fi

lled

gabi

on b

aske

t sur

-fa

ces

(all

roun

d) m

ust n

ot

allo

w p

oten

tial b

reak

out o

f in

divi

dual

rock

s.

• St

abiliz

es s

lope

or e

m-

bank

men

t•

Prev

ent s

oil e

rosi

on•

Abs

orb

wav

e en

ergy

• C

an b

e de

trim

enta

l if n

ot

desi

gned

and

con

stru

cted

pr

oper

ly

Initi

al c

ost –

med

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ThissectionwillprovideabriefupdateofbaselineinformationoncurrentcoastalprotectioninterventionsaroundsomeofthecountriesinthePacificregion.Thevariousengineeringapproachesusedbydifferentcountriesintheregionwillbepresented.

4.1CookIslands

IntheCookIslands,theengineeringapproachesusedareconcreteseawalls,rockboulderrevetments,groynes,rock breakwater, and beach replenishment. Specific locations of interest are the beach replenishment at theNortherncoastlineandrockmountedbreakwateratAvatiu.BelowaresomeexamplesofengineeringworksintheCookIslands:

Figure 25 Rock riprap wall, Figure 26 Avarua rock groynes, Figure 27 Gabion basket wall, Figure 28 Ngatangiia concrete wall (Source: Fig.25-28: He, 1999).

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Figure 29 Concrete Revetment west of airport. Figure 30 Rarotonga Hotel concrete revetment. Figure 31 Avarua Harbor seawall and revetment. Figure 32 Reclaimed Coast Protecti on: Te Tautua Village, Penrhyn Island, Cook Island. (Source: Fig.29-32: He, 1999).

4.2EastTimor(Timor-Leste)

Wavebreakers infrontoftheportofDiliandDiliAirport,mangroves,coastalandMarineProtectedAreasonsomeofTimor Leste’s coastare commoncoastalengineeringapproaches found inTimor Leste.Recently,bigstonesfromrivershavebeenplacedonstretchesofbeachcalled“PantaiKelapa”toserveaslow-costwavebreak-ers.ThemangroveplantingsiteoftheEU-GCCAproject is inUlmeravillage,sub-districtBazarteteanddistrictLiquica,thoughmangroveconservationisalsooneoftheprioritiesfortheGovernmentandNon-GovernmentalorganizationsinTimor-Leste.Inadditiontothat,Timor-LesteisworkingonICMwithinthecontextoftheCoralTriangleInitiative(CTI).Thecountryalsohasmanynationalparks,bothmarineandterrestrialamongwhichisacommunitybasednationalparkcalled‘NinoKonisSantana’

Figure 33 Mangroves in Ulmera village Figure 34 Wave breakers at port Dili, Timor Leste

4.3FederatedStateofMicronesia(FSM)

Seawalls,causewaysandgroynesarecommonengineeringstructuresfoundinFSM.ShownbelowaresomeoftheengineeringstructuresinFSM:

Figure 35 Concrete coral seawall. Figure 36 Coral rubble seawall. Figure 37 Coral seawall. Figure 38 Coral rubble seawall (Source: Fig. 35-38: Maharaj, 1998)


4.4Fiji

InFiji,causeways,bridgesandseawallsarebeingused.FijihasanIntegratedCoastalZonemanagementPlaninplace.ProtectedcoastalareasaretheGreatAstrolabeReefinOnoisland,Kadavu;NadiBay(Tai,Levuka,VomoSewaislandsfringingandoffshorereefareas);Namenalalafringingandbarrierreefs;YaduaTabafringingreefsandsurroundingwaters;andLauGroup.

TheprotectedmangroveareasareBaDelta-Nawaqarua-Natutu;RewaDelta-Muanicake-Nasoatariver;LabasaDelta-LabasariverandLabasadeltamouth.65

SomeofcurrentengineeringstructuresfoundinFijiarepresentedbelow:

Figure 39 Navulivatu concrete seawall. Figure 40 Lomeri concrete wall. Figure 41 Lomeri Rock wall. Figure 42 Lomeri rock wall.

Figure 43 Naitonitoni rip rap rock wall. Figure 44 Naitonitoni rock wall. Figure 45 Lami rubber ti re wall. Figure 46 Lami Gabion basket wall.

Figure 47 Concrete wall in Suva Wharf. Figure 48 Concrete wall in front of Civic Centre. Figure 49 Concrete wall in front of the President’s Residence. Figure 50 Rock wall at Suva Grammar beach front.

65DepartmentofEnvironment,(2011)


DepartmentofEnvironment,(2011)

Figure 51 Naselesele bridge. Figure 52 Rock wall. Figure 53 Naselesele rock wall. Figure 54 Rip rap rock revetment.

Someofthenaturalcoastalprotections

Figure 55 Korotogo Mangroves. Figure 56 Korotogo juvenile mangroves. Figure 57 Namada reef fl at. Figure 58 Namada inter-ti dal reef.

Figure 59 Namatakula Beach rock. Figure 60 Namatakula beach rock. Figure 61 Namatakula beach rock. Figure 62 Navulivatu Shoreline Mangroves.

Figure 63 Mangroves at Naselesele. showing aerial roots trapping sediments. Figure 64 Naselesele Mangroves, Taveuni


4.5Guam

ThecommoncoastalengineeringapproachesfoundinGuamarerevetments,seawallatEastAgana,VegetationatCocosIsland,coralboulderrevetment,concreteandrockseawall.

4.6Kiribati

ThetypesofinterventionsfoundinKiribatiareverticalcoralrockseawalls,cementverticalcoralrockwall,Ga-bionbasketfilledwithcoral,sandbags,cementfrontwall,slopingcoralrockwallwithcement,motorwaysandcauseways.SomeexamplesofseawallsinKiribatiarepresentedbelow:

Figure 65 Concrete Sandbag wall. Figure 66 Rock wall. Figure 67 Causeway Concrete wall. Figure 68 Concrete revetment wall at Parlia-ment House.

Figure 69 Bonriki Sloping sandbag wall. Figure 70 Concrete slabs at Oceanside of Bonriki airport. Figure 71 Sloping concrete wall at Red Beach, Beti o. Figure 72 Wave Breakers at Beti o Wharf.

Figure 73 Mangroves and sand bags wall at Bonriki. Figure 74 Dainippon Causeway Bairiki to Beti o. Figure 75 Private land-reclaiming project using sand bags wall at Bairiki. Figure 76 Sloping cement wall protecti ng Parliament House.


Figure 77 Concrete wall. Figure 78 Rock Wall Figure 79 Rock and concrete wall. Figure 80 Concrete wall.

Figure 81 Nanikai Stone wall. Figure 82 Tarawa sea wall. Figure 83 Mormon Church seawall. Figure 84 Reclaim seawall extend to lagoon. (Source: Fig.77-84: Woodroff e and Biribo, 2011)

Kiribatiusesmangrovesasaprotectivemeasureforthecoasts.ThePresidentofKiribatiH.E.DrAnoteTonghasbeeninstrumentalinempoweringKiribatiyouthtoplantmangroveseedlingsaseffectivemeasuresinprotect-ingerodedbeaches.

Figure 85 Mangroves. Figure 86 Mangrove project. Figure 87 Mangroves planted in lines. Figure 88 Juvenile Mangroves.

51


4.7MarshallIslands

Generallyspeaking,coastalprotectionintheRMIisintendedto“holdtheline”andmaintainafixedshoreline,i.e.limiterosionandtoalesserextentlimitfloodingandinundation.ThisisparticularlyevidentinthepopulatedcentersofMajuroandEbeyewherecoastalprotectionislargelyadhocandundertakenatthelevelofindividuallandowners.OtherthantherevetmentandseawallattheMajuroairport,therehavebeenfewcoordinatedorcentralizedcoastalengineeringinterventionspost-independence.Typicallylandownerswillarmorshorelinesus-inganyavailablematerial.Thosewithaccesstotechnicalandfinancialresourceswilluserip-raprevetmentandverticalconcreteblockorcementedcoralwalls.Gabionbasketsfilledwithcoralgravelarealsoused.Morefre-quently,amixofinorganicdebrisincludingtires,scrapmetalandoldheavymachineryisused.RecentlytheRMIendorsedguidanceintheformofapublicationonoptionsforcoastalprotectionforlandowners.

UniversityofHawaiiSeaGrantinassociationwithRMIagenciesisworkingwithcommunitiestobroadentheop-tionstoincludesofterridge-buildingandre-vegetationtechniques,alongwithamoreconcentratedapproachtoreefandreefflatprotection.Whileongoingworkintheouteratollsisstillfocusingonharderfortificationmea-suresandroadelevationalongcauseways,theapproachisbecomingmoreintegratedandinnovativeintermsofcombiningoptionswherepossible.Thiswillhavelongtermbenefitsofmainstreamingwithotherresourceman-agementobjectives(e.g.reefprotection)andmakingitmorelikelythatbenefitsfromlimitedadaptationfundscanbeusedoveralargerarea.

Figure 89 Rip-rap rock wall Figure 90 Sand bags Figure 91 Concrete stone wall(Source: Fig 89 - 91: Karl Fellenius)

Figure 92 Concrete wall Figure 93 Seawall structure Figure 94 Concrete wall(Source: Fig 92 -94: Karl Fellenius)

52


Figure 95 Seawall in Majuro. Figure 96 Seawall protecti ng huge buildings(Source: Fig.95 - 96: Murray Ford and Coastal Consultants NZ Ltd, 2013).

Figure 97 Seawall placed on rock. Figure 98 Breakwaters in Majuro.(Source: Fig.97 - 98: Murray Ford and Coastal Consultants NZ Ltd, 2013)

Figure 99 Vehicle ti re neatly stacked as seawall. Figure 100 Concrete wall. Figure 101 Seawall protecti ng oil tanks. (Source: Fig.99 - 101: Murray Ford and Coastal Consultants NZ Ltd, 2013).

4.8Nauru

ThecoastalengineeringapproachesusedinNauruareCoralboulderrevetmentandconcreteandrockseawalls.ThetwomajorcoastalengineeringworksdoneonNauruincludetheextensionoftheairportrunwayandtheconstructionofthenewboatharborinAnibareBay.HerearesomeexamplesofengineeringworkinNauru.

53


Figure 102 Rip rap rock revetment. Figure 103 Concrete wall. Figure 104 Long concrete wall. Figure 105 Concrete wall with rocks at base-ment. (Source: Fig.102 - 105: Maharaj, 2000).

Figure 106 rock revetment. Figure 107 layout of rock revetment. Figure 108 rock wall. Figure 109 rock wall protects a house(Source: Fig.106 - 109: Maharaj, 2000)

Figure 110 Nauru new wharf Figure 111 Rip-rap rock wall(Source: Fig 110 - 111: Maharaj, 2001).

Figure 112 Boat ramp and rip-rap rock wall Figure 113 Rip rap rock wall(Source: Fig 112 - 113: Maharaj, 2001)

54


4.9Niue

Niueissurroundedbynaturalhighcliffstructureswhichprotectstheislandfromwavesandstrongwinds.AseawallwasconstructedatAvateleBay.TherearetwoMPA’soneinAlofiandoneinMakefu.(fromNiueICCMsBirthaTogahai)

Figure 114 High Cliff of Tamakautoga, Niue Figure 115 High cliff s of Niue (Source: Fig 114 - 115: Susanna Sionetuato)

Figure 116 Walking down the cliff , Niue. Figure 117 Waves cuts the cliff below-Avatele Bay. Figure 118 Pathway down the cliff

Figure 119 Tall Concrete wall at Avatele Bay. Figure 120 Concrete Beach ramp, and seawall. Figure 121 Stone wall at Anaana point, Tamakautoga.

4.10NorthernMarianaIslands

Thecoastalengineeringstructuresfoundareseawalls,bulkheads,andbeachnourishmentatBeachRoad.

55


4.11Palau

TheshorelineofMelekeokstateinPalauconsistsofmangroves,sandybeaches,seawalls,reclaimedlandatthemarina,andgroynes.HerearesomeexamplesofengineeringworkinPalau:

Figure 122 Rip rap rock wall. Figure 123 Grouted rock wall. Figure 124 Rock wall Figure 125 Concrete wall (Source: Fig.122 - 125: Kench, 2008)

Figure 126 Ngerubesang rock groyne. Figure 127 Concrete groyne. Figure 128 Long groyne. Figure 129 Rock groyne at dock area (Source: Fig.126 -129: Kench, 2008)

Figure 130 Melekeok rock wall protecti ng the road Figure 131 Ngermelech rock wall(Source: Fig. 130 - 131: Kench, 2008)

56


4.12PapuaNewGuinea

InPapuaNewGuinea,coastalengineeringapproachesusedarebricksandrockseawalls,drystoneseawalls,coralseawallsandboulders.

Figure 132 Dry stone seawalls at Gapagapa village, central province, PNG

Figure 133 Stone wall at Mou Kele village. Figure 134 Sandbag and tree trunk wall. Figure 135 Rock wall at Gilibwa village. Figure 136 Gabion Basket wall at Los Negros Island.

4.13Samoa

InSamoathecoastalengineeringapproachesarestonewalls,volcanicbouldersatLufilufi,Vaialabeachseawall,semiverticalseawallatTusitalaHotel,revetmentatAggieGrey’sHotel,groynesatMulinwuPeninsula,largerockatoldHideawayHotelatMulivai,Revetmentandbeachreplenishment,ChinesefundedseawallatApiawaterfrontandatthebeach.

ThemainapproachesusedinSamoaarehardstructuralarmorrockrevetmentsorseawallsandsoftmeasuressuchasplantingofmangrovesandothersalt tolerantcoastalplantspecies.Thedesignsandconstructionsoftheseinterventionsaredoneonanadhocbasis.Onestandarddesignusescompactedbackfillscoriamaterial,geotextilecloth,secondaryandprimaryarmorrocksplacedat rightslopeandheight. (TakenfromMs.MoiraFaletutuluoftheMinistryofNaturalResourcesandEnvironment,Samoa),HerearesomeexamplesfromSamoa:

57


Figure 137 Parti al concrete revetment at Piula. Figure 138 Rock wall at Sataoa.(Source: Fig.137 - 138: Moira Faletutulu)

Figure 139 Aerial view of groynes along Mulinuu Peninsula shoreline. Figure 140 Rock wall and vegetati on. (Source: Fig.139: Nati onal Mapping Services, MNRE, Samoa. Fig. 140: Moira Faletutulu)

4.14SolomonIslands

ThemostpopularlowcostengineeringapproachintheSolomonIslandsforcoastalprotectionistheuseofsea-walls.Thesearebuilt fromrockbouldersfromthesurroundingcoastalenvironment.AsshowninFigure141,wheretheseawallisvulnerabletorelativelyintensewaveaction,itisreinforcedbywoodenpillarsimpaledintothebenthos.Becausethelifespanofpillarsisnotthatlongthereforeitrequirescommunityorfamilyefforttomaintainthem.

Someseawallsaremadeofcoralbouldersfromthereefsreinforcedbylogs.Figure142belowshowssuchawallattheSouthernendofNolaHamletinNgawaIslet(ReefIslandsgroupingofTemotuProvince).SeawallslikethisarealsoreinforcedbytherootsofAbalolotreesthatinterlocktherockstogether.

Mangroveforestsalsoplaysamajorrole incoastalprotection intheSolomon Islands,unfortunatelytheirex-ploitationhaveseendramaticincreaseindenselypopulatedareasaroundthecountry.TheLangalangaLagooninMalaitatheSolomonIslandshasseenagreatdealofmangrovedeforestationinthelast15years,increasingcoastalerosion.InNgawaIslandintheReefIslands,thecommunityinanattempttoprotecttheircoastsfromerosion,decidedtoplantmangrovetrees,alongtheircoastintheintertidalzone.Accordingtothevillages,themangroveshavestartedhelpingtheretrievalofthecoastline(seefigure,143).Initiativeslikethesecanonlybeeasilypursuedandachievedthroughgreatercommunityparticipationastheprocessesofplantingandcaringforthemangroveshastocomefromthecommunityasawhole.

58


Figure 141 Rock Boulders seawall Figure 142 Rock seawall Figure 143 Mangrove Planti ng Theuseofconcreteseawalloftenrequiresmajorinvestments.Theycanbeverycostlytobuild,thusareonlysuit-ableandpracticalinurbanareasandareaswhichhavesomelevelofdevelopment.InSolomonIslandsexamplesincludes,theHoniaraPortsArea,HoniaraCentralMarketandmajorhotelsthatoccupythecoastlinewhichhaveconcreteseawalls.Despitetheircostliness,theyareproventobemoredisasterproof.

Seawallswhichusegabionnetsarealsoeffectiveandcostlybutunlikeconcreteseawalls,theirlifespandependsontheabilityofthewirestoresistcorrosion,theirexposuretophysicalforcesofnaturesuchaslargeoceanswellsandthechemicalpropertiesoftheoceanorestuary(AnupdatefromResearchAssistantJohnWha-leneanea).

Figure 144 Breakwater structure. Figure 145 Gabion structure. Figure 146 Breakwater structure. Figure 147 Concrete revetment. Figure 148 Concrete seawall.

59


Figure 149 Mangroves in Ulmera village Figure 150 Wave breakers at port Dili, Timor Leste

4.15Tonga

InTonga,limestoneboulderseawallatNukualofabeachfront,andbeachsandseawallatHihifointhewesternareaareused.BreakwaterinEuaIsland.TheseawallatthewaterfrontofNukualofawasconstructedaftercycloneIsaacof1982andcompletedaround1985-86.Thiswasconsideredhighlysuccessfulinprotectingthebeachfrontinthecapitalarea.TheKanokupoluSeawallwasconstructedbythevillagersthemselveswithsomeassistancefromNGOs,GovernmentsandDonors.Thishasbeenverysuccessfulatpreventingfurthererosionatthesite,butonceagainamajorheadacheattheedgeoftheseawallwheretheneighboringvillagesarenowfacingcoastalinundationatagreatermagnitudeandfrequency.SoftengineeringapproacheshavebeenconductedinmoreshelteredlagoonsitevillagessuchasLapahaonthemainislandofTongatapu.Mangrovereplantingandcoastalplantreforestationisongoingastheyattempttoreducetheimpactsofinundationandcoastalerosion.TheuseofsandbagswaspilotedbyonecommunityinHa’apai.Thisprojectwasnotsosuccessfulastheyusedbagsthatwerenotdurable,howevertheconcepthasitsmeritsintermsoftheavailabilityofresourceslocally,andjustneedsfurthermodificationstogetitright(AnupdatefromInCountryCoordinator-Mr.TevitaFakaosi).

Figure 151 Concrete seawall. Figure 152 Waterfront seawall. Figure 153 Rock seawall. Figure 154 Sandbag seawall-Tonga (Photo credit: Fig.151 -154: Tevita Fakaosi)

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4.16Tuvalu

InTuvalu,thecommonengineeringapproachesareseawalls,gabionbasketofstones,andconcretecuberevetment.

Figure 155 Concrete wall behind the boat. Figure 156 Concrete wall at Wharf. Figure 157 Concrete cubes beach ramps.

Figure 158 Private wall made up of 44-gallon drums fi lled with concrete. Figure 159 Concrete wall in front of Hotel. Figure 160 Nukufetau jett y and reef channel. (Source: Fig 158: Ms. Makereta Komai. Fig 160: Temata Shozo)

Figure 161 Niutao causeway and Mangroves. Figure 162 Nukulaelae beachramp. Figure 163 Concrete wall in Funafuti .

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Figure 164 Stone beach south Fogafale. Figure 165 Stone beach and reef. Figure 166 Storm Bank just aft er Hurricane Bebe 1972. Figure 167 Nukulaelae storm bank. (Source: Fig.166: Tuvalu Meteorological Stati on)

Figure 168 Vaitupu Fisheries Harbor. Figure 169 coral rubble at Vaitupu. Figure 170 Vaitupu reef. Figure 171 Vaitupu seagrass. (Source: Fig.168 -171: Xue, 2002).

4.17Vanuatu

InVanuatuthereisaseawallinPortVilaHarborwhichwasdamagedbyacyclone.Vanuatucomprisesofover83inhabitedislands.Mostpeoplelivingonthecoasthavemoreorlessignoredordonenothinginthenameofengineeringtocountertherisingsealeveland,orcoastalerosion.Some–oncoastalcalmwaters–haveresortedtopilinguprockscollectedfromthesand.Thisisnotveryeffectiveasitiseasilywashedawayduringstorms.Oth-erswhohaveextrafundstospendmightbeableto,orhavebuiltconcretewallsorusecementtoholdtherockstogethertoformaseawall.Thisagainisnotveryeffectiveeitherduringroughstormsandovertimewhenthewaterdigsaroundthewalls.Yetotherswithfundsandorwithexternalsponsorshiplayoutgabionbasketsandfillthemupwithrocks.InLuganvilleandPortVilasomeportionsofthecoastshavebeenburied(landreclamation)andconcreteandmetalwallshavebeenconstructed.TheseengineeringworksweredoneduringthecolonialeraandmostlybytheAmericansduringtheirbriefstayinthecountryduringthesecondworldwar.Alotofmoneywasputintothisinitiativeandalsobecausethewaterconditionsinthesetwolocationsisnormallycalm,thesestructureshavebeeninplaceforquiteawhileandcanstillbeseentoday.Sealevelriseandfrequentcyclonesinthe90shaveerodedthemetalwallsinLuganvilleandrecentstormshavedamagedpartsoftheconcrete/metalseawallinPortVila.Almostalltheattemptsdiscussedoccurwherethewaterisusuallycalm.Areasconstantlyexposedtoroughseaslargelyignoreanyengineeringworkatallaspeopleknowtheireffortswillbefutile.(AnupdatefromVanuatuICC-WilliamBaniArudovo).

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Figure 172 Concrete structure at Vanuatu. Figure 173 Same concrete structure.

Figure 174 Veti ver Grass at Piliura village on Pele Island. Figure 175 Gabion basket at Worasiviu. (Source: Fig.174 -175: Christopher Bartlett - SPC/GIZ)

4.18Interventionsthatdidnotwork

Let’snowturnourattentionandtryandcaptureinterventionsthatdidnotworkinsomeoftheselectedPacificcountries.Photosbelowwilltellthestory:

ExamplesfromCookIslands:

Figure 176 Sea erosion caused by failed seawall. Figure 177 Collapsed seawall in Cook Islands. Figure 178 Collapsed groyne at west end. (Source: Fig. 176 -178: He, 1999)

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ExamplesfromFiji

Figure 179 Part of seawall at Lomeri High School collapsed. Figure 180 Same seawall looking from seaside. Figure 181 Poor engineering work

Figure 182 Tire wall collapsed at end of seawall. Figure 183 Tire wall was ineff ecti ve. Figure 184 Vehicle ti re wall at end collapsed

ExamplesfromFSM

Figure 185 Polap Island erosion at toe of seawall. Figure 186 Collapsed seawall at Satawan Island. (Source: Fig 184 -185: Maharaj, 1998).

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ExamplesfromKiribati

Figure 187 Erosion at end of seawall-Eita, Tabiteuea North. Figure 188 Collapsed seawall-Tewai school, Tabiteuea South. Figure 189Collapsed seawall at Temotu island, Nonuti . (Source: Fig. 187 -189: Gillie, 1993).

Figure 190 Collapsed wall at Roti ma, Nonouti . Figure 191 Eroded road and seawall collapsed at Roti ma..Figure 192 Collapsed concrete fi lled sandbag wall at Nonouti . (Source: Fig.190 -192: Gillie, 1993).

Figure 193 Collapsed seawall in Abemama. Figure 194 Collapsed seawall in Kuria. (Source: Fig.193-194: Gillie, 1993).

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Figure 195 Erosion of important monument. Figure 196 Remains of stone wall. Figure 197 Gabion basket -broken wire.

Figure 198 Erosion begins where wall ends. Figure 199 Erosion at end of seawall. Figure 200 Erosion seen at toe of sandbag wall.

ExamplesfromSamoa

Figure 201 Collapsed seawall in Samoa (Source: Yamamoto and Esteban, 2011)

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ExamplesfromTuvalu

Figure 202 Collapsed Concrete cube Seawall at Nanumaga. Figure 203 Collapsed Concrete cube revetment at Funafuti . Figure 204 Collapsed Gabion basket wall and Tree Trunk wall at Nukulaelae. (Source: Fig.203: Tuvalu NBSAP)

Figure 205 Damaged boulders at toe of concrete seawall, Funafuti . Figure 206 Damaged seawall at Vaiaku Lagi Hotel. Figure 207Collapsed concrete cubes revetment. (Source: Fig.205 -207: Xue and Malologa, 1995).


Basedonthepreviouschapters,thischapterprovidesasummaryofkeyPacificandothersmallislanddevelopingstatesexperiencesofthevariouscoastaladaptationsystemandprocesses.Thefollowingareselectedcasestudiesthatillustratesomeofthepromisingcoastaladaptationsystemsandprocesses.Thesesystemsandprocessesare:

•Hardcoastalstructures; •Softcoastalstructures; •Bio-physicalstructureand •Coastaladaptationmechanism.

5.1HardCoastalStructures

Solomon Islands

Building Stone Walls (TonyWale,Aoke,LangalangaApexAssociation,Honiara,SolomonIslands) ThissimplemethodhasworkedforthecommunityofLangalangaLagoon.Theyareseeingsanddepositedatthecoastandtheirbeachgraduallybeingreplenished;mangroveswillbereplantedalongthestonewalltocreateabufferzonefortheirshores.

Samoa

Groynes (fromKevinPetrini,UnitedNationsDevelopmentProgrammePacificCentre,Suva,Fiji) InSamoatheywereoptingforconstructionofgroyneswhichmightprovetobea“lengthyandrelativelyexpensive”intervention.

Chapter 5: selected examples of pacific experiences By Luke Paeniu, Viliamu Iese and Isoa Korovulavula


Nauru

Rock Extensions(GodfreyWaidubu,MedicalOfficer(ClimateChange),Nauru)InNauru,theerectionofwhatwasconsideredaminorseawalli.e.rockextensionstothereefintheshorttermwouldprovidethenecessaryprotection.However,inthelongtermitwouldcausethemovementofsandinlargevolumestootherareas.Hence,mostoftheseawallsorextensionswouldbecomebarewithoutsandonbothsidesanddependonthecoastalprocessesinthatgivenarea.AsinthecaseofNauru,thesandstartedtoaccu-mulateagain.

Murray Ford and NZ Consultants Ltd (2013)

Inarecentpublication“ALandowner’sGuidetoCoastalProtection”,someimportanttipswereshared:Indesigningseawalls- it isbettertohavewallsthatarehigherthanthewavesheight,especiallykingtideandstormwaves.Ensurethatthetoeoftheseawallisbuiltinawaythatitisnotscoured.Thewallshouldbeextendedlongenoughtoprotectadjacentcoastsandnotonlyinfrastructureonthesite.Theseawallshouldbebuilttowithstandwaveenergyanddebristransportedbywaveactionsandcurrent.

Incasesofrevetment,wallsshouldbehighenoughtoavoidwavesovertopping.Placingoffilterclothisnecessarybeforebuildingarevetment.Ensurethefoundationisprotectedfrombeingeroded.Theslopeoftherevetmentshouldbe1:2orat300angle.Thestructureshouldbestrongenoughtowithstandhighenergywaves.Groynesarebuilttobehighenoughtotrapsandandsedimenttransportedalongthebeach.Thegroynesshouldbeextendedlongenoughtocapturethesandmovement.Spacingoutgroynesisimportantandthepreferredoptionistohavethemthreetimesthelengthofthegroynes.Breakwaterstructuresshouldbebuilttobehigherthanthestormwavesheightsothatitbreaksofftheincomingwaves.Breakwatersbuiltfarfromthebeachwillhelpreducethewavesenergyandhelpbuildabeachontheleewardside.Theuseoffilterclothisrecommendedwhenbuiltonasandybeach.Itisalsowisetobuildbreakwatersthataresubmergedinthesea.

5.2SoftCoastalStructures

Federated States of Micronesia

ReplantingMangroves and Pandanus (Vita Akapito Skilling, Secretary of Health and Social Affairs, FederatedStatesofMicronesia)

Inattemptingtodissipatetheenergyfromthewavesthaterodetheshore,womenofKosraearereplantingman-groveforestalongthecoastline.InPohnpei,thewomenareplantingpandanustreesalongthecoast,especiallyontheatollislandsinthehopeofslowingdowntheerosionandprovidevitaminArichfoodsforthepeopleresid-ingontheislands.

Tuvalu

“Foraminifera”inTuvalu(ShigekiIshigaki,JapaneseInternationalCooperationAgency(JICA),Suva,Fiji)The Foram Sand Project is a joint research project by Japanese and Tuvalu research organizations and waslaunchedwiththesupportofJapanInternationalCooperationAgency(JICA)andJapanScienceandTechnologyAgency(JST).Thisprojectaimstoreproducelocalspeciesofforaminifera(atypeofmicroscopicmarineorganismwithasilica-basedcellwall)toproducenew‘foramsand’thatcanbeusedtoreplenisherodedareas.Thedown-sideofthisinitiativeisthehighcostinvolvedandslowgrowth.

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Samoa

CommunityBasedAdaptationInitiatives(KevinPetrini,UnitedNationsDevelopmentProgrammePacificCentre,Suva,Fiji)

AspartoftheirCBAproposal,someofthesoftsolutionsrelatedtowatershedmanagementandmarineprotectedareaswere identified.Forhardsolutions,however, theywereoptingforconstructionofgroyneswhichmightprovetobea“lengthyandrelativelyexpensive”intervention.Relocationandcontinuingwithothersoftmeasuresremainasthebestpracticesforcoastalprotection.

Caribbean Barbados

The3StrandsStrategy(LornaInniss,CoastalZoneManagementUnit,Barbados)InBarbados,abestpracticeinthisareaofcoastalclimatechangeadaptationconsistsofthree(3)strands:Pro-tection,conservation,restorationofthefivenaturallinesofdefenseagainsthighwaterlevel(mangroveswampsandothercoastalvegetation,beachesandsanddunes,seagrassbeds,fringingreefs,andbankreefs),Controlofhumanbehaviorthrougharigorousregulatoryframeworkandasthelastresortusetargeted,well-designed,science-basedshorelinestabilization“hard”structuressuchasgroins,breakwatersandrevetments.

Vanuatu case study - Traditi onal Marine Protected Areas(WilliamBaniArudovoIn-CountryCoordinator,Vanuatu)

Apalmleaferectedonthecoastliketheoneinthephotobelowsignifiesatabooandcouldmeaneitheroftwothings:

•someoneisdisputingownershipofthisparticularcoastalareaandhence,thisprohibitsusage ofresourcesand,orstopsanydevelopmentthatislikelytotakeplaceinthearea

•Thissignifiesataboo(stop)totheharvestofmarineresourcesinthearea(MPA)untilsuchtime whenthepalmleafisremovedbywhoeverplacedit.Therewouldusuallybeanumberof leaveserectedforthispurposetoindicatetheboundaryoftheMPA.

Onehastoaskaroundwithinthecommunityinordertoknowtheexactpurposeoftheleafthatwaserected.

Figure 208 Traditi onal MPA in Vanuatu

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Papua New Guinea case study - Marine Protected Area (MPA)

(RoseGodana,PNG)-Outofthe52protectedareas,therewerenineMPAinPNG.InMadangprovincetherewerethreesites-Baqiai(13,760ha);CrownIslandWildlifesanctuary(58,969ha)andRanba(41,922ha);KamialiofMorobeprovince(65,541ha);MazaofWesternprovince(184,230ha);NdrolowaofManusprovince(5,850ha);PirunqofNorthSolomonprovince(43,200ha);TaleleIslandNationalParkReserveofEasternNewBritain(12ha)andTavaloofEasternNewBritain(2000).PNGisincludedintheCoralTriangleInitiative(CTI).TherearefourCTIdemonstrationsites.TheyarelocatedinManua,Kimbe,MilneBayandMadangprovinces.TheKimbeBayMarineManagementAreaisanetworkcomposedof11locallymanagedmarineareaswhereCTIisworkingat.

Samoa case study – Marine Protected Area (MPA)

SamoahasMPAsinAleipataandSafata.Theprojectgoalwastoprovideforthesustainableuseandprotectionofcoastalmarinebiodiversitywhichisunderthreatinthesetwolocations.InAleipatadistrict,protectionwasfocusedoncoralreefs,nestinggroundofseabirdsandfeedingandnestinggroundsforturtles.InSafataconserva-tionmeasuresaretargetingcoralreefs,lagoonandmangroveshabitats.

Fiji- LMMA

FijihasinitiatedanetworkofLocallyManagedMarineAreas(LMMA)aroundtheregion.Theideaistoshareex-periencesonhowmembercountriesinthePacificconducttheirownLMMA.SomeexamplesofLMMAarefoundinPNG,wheretheyhaveM’bukeAilanMarinMenesmenEria,ManusProvince.IntheSolomonislandstheyhaveCommunityBasedManagementofMarineResources in Jorio,VellaLavella. InVanuatu, theyhave integratingnatural resourcemanagement,ecosystemswithsocial,political,economic,environmentalelementsatMarouandEmua,NorthEfate.InFiji,theyhavetheNamenaMarineReserve,Kubulau,BuaIsland.IntheCookislands,theyhavetheAiutakitrochusmanagementexperienceofcontrollingoverharvestingoftrochusshells.InTuvalu,theyhaveIslandConservationAreasinTuvalu,animprovementofmarineresourcemanagement.InSamoa,theyhavetheCommunitybasedFisheriesManagementProgramme.IntheMarshallIslands,theyhaveReimaanlok-Developinganationalconservationareastrategy.WhileinFrenchPolynesia,theyhavetheManaandBiosphereconservenaturalbiodiversity,ecosystemsandlandandseascapeprogramme.

Tuvalu case study - Planting of Coastal littoral vegetation

LikeallPacificcountries,therearenaturalcoastallittoralvegetation.Therearegrassesandplantsgrownonbeachareas, followedbyplantsandtreesbeyondthehighwatermark in land.These littoralvegetationarenaturalformedofcoastalengineeringstructuresthathelpsinprotectingtheisland.InarecentpublicationofthePlantsofTuvaluwrittenbyThamanetal.(2012),thecreepingvineknownasbeachmorningglory(Ipomoea pes-caprae) arenormallyfoundoncoralrampartofoceancoastofFogafale,Funafuti.Beachheliotrope(Tournefortia argen-tea)arecommoninbeachesofTuvaluplaysimportantroleinstabilizingbeachesandprotectingcoastlines.Salt-grass,swampcouchgrassandseashorepaspalum(paspalum vaginatum)aredensegrassesformednearbeachesinTuvalu.Burrgrass(Cenchrus echinatus)isaweedygrassoftenfoundinsandyareasnearthecoastinTuvalu.Anothercommonshrub (Scaevola taccada) is found inabundant incoastal littoralvegetation.The largetreesthathelpprotectthebeachesinTuvaluareCalophyllum inophyllum, Barringtonia asiatica, Thesapesia populnea, Cordia subcordata and Luumnitzera littorea.66

66ExtractedfromThamanetal.(2012)

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Tonga case study- Coastal reforestati on in Tonga to protect coastlines (Prof.RandyThaman,AndrewSmithandTevitaFaka’osi).67

Over30indigenousspecieswereplantedinthreephasesovera2kmofcoastlinesinTonga.Thesespeciesin-cludedcoconutpalms,Panadanus tectorius,Hibiscustiliaceus,Excoecariaagallocha,Calophyllum inophyllum,Hernandianymphaeifolia,Terminaliacatappa,Tournefortiaorgentea,BarringtoniaasiaticaandNeisospermaop-positifoliumandotherspecies.Theyplantedcasuarinasintworowsaswindbreakersandontheleesideofthesecasuarinastheyplanted30indigenouscoastaltrees.Aftersixmonthstheyplantedlesstoleranttrees.Finallytheyplantedhardtreestoincreasediversity.

Veti ver grass (DrChristopherBartlett,SPC/GIZCopingwithClimateChangeinthePacificIslandsRegion,Vanuatu)68

TheSPC/GIZjointinitiativeshopetoenablelocalcommunitiestocopeinwaysthatarenotprohibitivelyexpen-siveandarelocallyimplementable.Theseinitiativesincludelanduseplanning,sand/aggregateminingcontrol,rehabilitating/replantingcoastalareaswithindigenousterrestrialvegetationsuchascreepingvinesandplantingof‘vetiver’grasstocontrolbothinlandandcoastalerosion.AlsoincludedintheprogramarehardtechnologiessuchasGabionbaskets.

TheplantingofVetivergrassisasuccessfuloneinFijiespeciallyclosebytheriverbank.Thesoilisrichenoughtoassistinthegrowthofthevetivergrass.

Figure 209 Veti ver grass fully grown. Figure 210 Planti ng of Veti ver grass near river bank(Source: Photo credit Mr. Leone Limalevu)

MoreinformationonVetivergrasscanbefoundinthemanualbyFenemor et al., (2010)- Veti ver: The proven soil conservati on technique. A training manual for communiti es and fi eld workers.

Vanuatu case study- A revegetati on technique to prevent sediment damage to fringing reefs in Vanuatu. (DonMillerandJamesComley).

SeveresoilerosionoverthesteepslopesofAneityuminVanuatuovermanyyearshavecauseddamagedtothefringing reefat sea.Thesolutionwas theuseofeffectiveVetiverplants-Chrysopogon zizanioides.Theywereplantedaroundhillslopestoholdbackthesoilfromerosion.Thisrevegetationtechniquewasasuccessfuloneasitreducessedimentationerosionandimprovecoralreefhealth.

67WilkinsonandBrodie(2011)p.82-8268WilkinsonandBrodie(2011)p.58-59

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Fiji Case study- Implementi ng Ecosystem-based management (StacyJupiter) 69

TheWildlifeConservationsociety,WetlandsInternationalOceaniaandtheWWFSouthPacificprogrammede-velopedand implementedEBMwithintheVatuIRaandCakaulevuregionofVanuaLevu.TheyproducedtheKubulauEBMPlan.

Fiji case study- Integrated Coastal Management in Vanuaso Tikina, Gau Island. (DrJoeliVeitayaki)70

Thevillagerswereabletodeveloptheirresourcemanagementplantopreservetheirenvironmentresources.Amongtheiractivitiestheywantedtoconservepartsoftheirfishinggroundsusingtheirtraditionalrights,prohib-itingtheuseofdestructivemethods,protectingandrehabilitatingmangroveforestsandcoastalvegetations,andmanymore.TheICMwassuccessfulastheydeclaredano-takezoneinsixvillages,theybuiltstonebreakwaterstoprotectthecoastsinNaovukaandLamiti,replantingofcoastalforests,restockingofgiantclamsinprotectedareas,replantingofmangrovesetc.

Niue Sustainable Coastal Development PolicyNiueismovingintherightdirectionwithitssustainablecoastaldevelopmentpolicy.Itsvisionis‘asafe,produc-tiveandsustainablecoastalenvironmentforNiue”.Ithassixmajorthematicgoals:

1.UpholdingcoastalareasasnationalTaogaforallNiue 2.Integratedcoastalplanning,managementanddevelopment 3.Pollutioncontrolandwastemanagement 4.Sustainablemanagementanddevelopmentofcoastalresources 5.Disasterriskreductionanddisastermanagement 6.Strengtheninggovernanceandcapacitybuilding71

5.3BiophysicalStructures

Niue case study

Niue,‘theislandoftherock’hascliffsthatofferbestexamplesofnaturalformsofcoastalprotectionstructures.

Figure 211 Niue cliff with wave acti ons Figure 212 Niue High Cliff s Figure 213 Niue’s cliff as front-line of defense

69ibidp.74-7570 ibidp.72-7371 SOPAC(2008)

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5.4CoastalAdaptationMechanism

Thissectionwillpresentthreeofthemaincoastaladaptationmechanisms.Thesemechanismsare:

•Participatoryapproach; •ToolsandDesigns; •Relocation.

5.4.1Participatoryapproach

Oneofthemosteffectivemeansofensuringsustainabilityofanycoastaladaptationinitiativesistheinvolvementofaffectedstakeholdersinparticularthecoastalcommunities.Therefore,participatoryapproacheshavebeenproventobeaveryeffectivemeansofensuringthattheaffectedcommunitiesareinvolvedintheimplementa-tion,maintenanceandrehabilitationworkoftheirbuiltand/ornaturalcoastalprotectioninitiative.

Vanuatu-‘CommunityParticipatoryModel’onEpiIsland(fromIanIerct,PacificAdaptationtoClimateChangeProject,PublicWorksDepartment,PortVila,Vanuatu)

The‘CommunityParticipatoryModel’becameaworkableinterventiononEpiIslandduetoproperconsultationswiththecommunityleadersandabetterphysicaloverviewoftheroadissues.Theyinturn,identifiedtheaffectedareasaroundthecoastandagreedtogive‘forfree’theirlandandresourcesforPACCprojectimplementationonEpi.ItishopedthatthismodelisreplicatedinotherislandsinVanuatuandothercountries.

Coral Triangle Initiative (CTI)

FivePacificcountriesarewithintheCoralTriangleInitiative(CTI),whichincludeTimorLeste,PapuaNewGuinea,Fiji,VanuatuandtheSolomonIslands.TheCTIprogramswouldleadtoimprovingmarineandcoastalecosystemswhich in turnenhance foodsecurityandbuildcapacity in integratedcoastal resourcesmanagement in thesecountries.InTimorLeste,CTIwillintroduceintegratedcoastalresourcemanagementandecosystembasedfish-eriesmanagementinBatugedeandAtauroIslands.InPNG,CTIwillundertakecoastalresourcesmanagementinKimbebayandManusIsland.InFiji,CTIwillintroduceLocallymanagedmarineareacommunitybasedmanage-mentmodelinRaProvince.InVanuatu,CTIwilldevelopplanningincoastalcommunities.TheCoralTriangleInitia-tivewillfocusattentioninMalaitaandIsabelProvince.

Fiji - Linking initiatives to Livelihoods and Well-being (FloydRobinson,UnitedNationsDevelopmentProgrammeMultiCountryOffice,Suva,Fiji)

Acritical factorwhenworkingwithcommunities is linking initiatives to their livelihoodsandwellbeing.Com-munitysupportisenhancedoncetheyunderstandandidentifythelinkbetweentheestablishmentofnofishingzonesandreplanting(mangroveplantsnotonlyprotectedthecoastlinebutalsoattractedcertainfishspecieslikemulletsandcrabs).

5.4.2ToolsandDesigns

TherearemanytypesoftoolsidentifiedthathavebeenputtouseinthePacificforcoastalprotectionandtheyincludethecoastalcalculator,GIS,mappingtool,GPS,thecoastalprotectionguidelineandfactsheets.Somede-signsofseawallsarealsoidentified.

Cook Islands ‘CoastalCalculator’(PaulMaoate,PacificAdaptationtoClimateChangeProject,MinistryofInfrastructureandPlanning,CookIslands)

Thecreationofthe‘CoastalCalculator’isanidealexampleofPACCCookIslands’efforttoincorporateclimatechangerisksintosustainabledevelopmentprogrammes.

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Itwasdesignedtohelpengineersdeterminewaverun-upduringstormsandhurricanes,aswellasallowthemtoincludesea-levelriseprojectionsinthedesignsofharborsandcoastalinfrastructure.

Collect good quality maps and aerial photographs

Itisimportanttogatherdigitalimagesof‘hotspots’orproblematicareasofthecoast.Theuseofdigitizedsatel-liteimagesthroughGIS(geographicalinformationsystems)technology,GPSandGoogleEarth.Mappingoftheimportantareasprovidesvitalinformationtoguidedecisionmaking.Inmostcasesthelocalcommunitydoesnotenjoyaccesstothesetechnologiessooutsidehelpmightbesoughtafterinsuchcases.AgoodcasestudywasthatwrittenbyLaurettaBurkeandZacharySugg(Watershed-basedthreatanalysisfortheMesoamericanreef:UsingthepowerofsatellitesandGIStechnologytotackleproblems).TheinformationgatheredfromGIStechnologywashelpfulinrecommendingbestpracticestoreduceerosionandpollution.

Figure 214 Using GIS as a tool to highlight at risk areas by calculating height above sea level. (Image by Siu I Fanga Pouvalu , Kevin Mai-tava, Andra Whiteside and Mavis Yuen). Kiribati case study

KiribatihasaCoastalprotectionguidelinedevelopedwiththeassistanceofBecaInternationalConsultantLtdin2010toprotectcoastline.Thefollowingareessentialstepstaken:

Step1-identifycoastalhazardsandcoastalprocesses Step2-assessthecoastline Step3-choosehighrisksite Step4-collectessentialinformation Step5-observecurrentstatus(existingenvironment) Step6-reviewinformationcollected Step7-decidewhattodo Step8-Consideralloptions Step9-Profilesurvey Step10-outlinedesign Step11-comparedesign Step12-obtainapprovals Step13-detaildesignandpre-construction Step14-qualitycontrolduringconstruction

KiribatihascreatedtheWorld’slargestmarineprotectedarea.ThePhoenixIslandsProtectedArea(PIPA)coversanareaof410,500km2.

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SOPAC Fact Sheet

SOPAChasdevelopedaFactsheetNo.7wheretheyprovideinformationaboutcoastalerosioninthePacific.Thisisonewayofbuildingawarenessintheregiononcoastalerosion,coastalprotectionandadviceonerosion.Sometipssharedwere:

Whatyoushoulddoabouterosion?:

•Complywithbuildingcodesandzoningplans •Consideralloptionsandplaneffectivestrategy •Understandyourcoastalprocesses •UseGISandmapouttheaffectedarea •Donotbuildadjacenttobeachleaveareasonablespace

Whattoavoid?:

•Donotdisturbthemovementofsandandwaves •Avoidbuildingtooclosetothebeach •Avoidbuildingseawallunlessnecessary •Avoiddumpingofsolidwasteonbeach

(Source: SOPAC (2007)).Kiribati Seawall designsTheuseofsandbagsasseawalls:

Figure 215 Design of sandbag seawall in Kiribati . (Source: Holden (1992))

BecaInternationalConsultantsLtdwassuccessfulinintroducingsomecreativeseawalldesignsforKiribatiaspartofKAPIIproject.Theseincludetheuseofsandbagseawalls,reinforcedconcretewalls,andplantingofmangroves.TocitemoreseawalldesignoptionsseetheKAPIIreportbyBecaInternationalConsultantLtd.

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5.4.3Relocation

Fiji – Relocati on

ForthefirsttimeVunidogoloavillageundertheProvinceofCakaudroveinVanuaLevu,Fijiwasrelocatedthroughthegovernmentnewclimatechangeprogram.TheVunidogoloavillagerelocationprojectwascompletedin2014andwasofficiallyopenedbythePrimeMinisterVoreqeBainimarama.Thevillageislocatedclosetothesea.Thereasonbehindtherelocationwasduetosealevelrisewherethevillageeasilygetsfloodedduringhightide.QuiteafewotherrelocationprogramsfacingalmostthesameproblemsareinthepipelineinFiji

Figure 216 Relocated Homes Figure 217 Top of cliff looking down to the sea,Niue Images By. Teddy Fong

Niue – Relocati on HigherGround(HadenTalagi,PacificAdaptationtoClimateChangeProject,DepartmentofEnvironment,Alofi,Niue)

RelocationwasfoundtobethemostsuitablecoastalprotectionmeasureinNiue.Thisentailedmovingfromthelowerterracetotheupperterrace,20metersto30metersabovesealevelandalsorelocatingfurtherinland.ThismeasureiscosteffectiveascomparedtobuildinginfrastructurethatcanwithstandaCategory5cyclone,similartotheonethathitNiuein2004.

Samoa – Relocati on

(KevinPetrini,UnitedNationsDevelopmentProgrammePacificCentre,Suva,Fiji)InSamoarelocationandcontinuingwithothersoftmeasuresremainasthebestpracticesforcoastalprotection.

5.5AssessmentofCoastalErosioninFSM

(RecommendationsofferedbyMaharaj(1998)

•DonotconstructseawallsandGroynes •Donotreclaimbeaches,mangrovesandreefareas •Donotminethebeachessurfzoneorbackreefareas •Donotblastthereeforcutreefchannels •Donotbuildalongthebeachfront •Buildingsshouldbesetbackfromtheshoreline •Donotdestroyshorelinevegetation

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•Re-vegetatethecoastline •Donotdisposeofwasteandgarbageinmangrovesandreefs •Obtainaggregatefromadjacentuninhabitedislandsorthemainland •Nourishbeacheswherepossible •AirportconstructionshouldbeprecededbyEIA’sandEIS •Relocateandredistributepopulationincrowdedareas •Educatepublicontheuseandmanagementofcoastalresources.

5.5.1ScientificapproachestoCoastalManagement

Pacificcountriescouldbenefitfromadoptingscientificapproachestothemanagementofcoastalzones.Someoftheseapproachesareintegratedcoastalzonemanagement(ICZM);Ecosystembasedmanagement(EBM);Marinespatialplanning(MSP);Ecologicalmodelling;andmappingtool.ICZMisadynamicprocesswherebybothhumanandecologicaldimensionsareconsideredforsustainableuseandprotectionofcoastalzones.TheEBMtakesintoaccountthecumulativeinteractionsofdifferentactivitiesandimpactsanddefinesthestrategicobjectivestosustainablymanagethem.MSPactuallyfocusonplanningofdifferentusesofcoastalandmarineecosystemandfindingsolutionstotheseproblems.Ecologicalmodellinghelpsincreatingunderstandingofhowmodelsandprocesscontributetoeffectivecoastalmanagement.72

72 Nobre(2011)

78


Chapter 6: ConclusionS

By Luke Paeniu, Viliamu Iese and Isoa Korovulavula

Inthisreportwehavedefinedthecoastasthezonewherewavesandlandinteract.WehavealsodescribedwhycoastsareimportantinsatisfyinghumanneedsintermsofhowPacificIslandersusethecoastformanypurposes.TheproblemfacingPacificcountrieswithregardstothedeteriorationoftheircoastlinesarealsoontheriseastheycontinuetobepopulated,whilethesecoastlineskeepchangingasaresultofthenaturalclimateandespe-ciallyasaresultofthehumanengineeringinterventionsthathavetakenplace.

Theprimaryaimofthisreportwastoprovideimportantguidelinesandlessonsofcoastalprocessesandbeachdynamics,differenttypesofinterventionsandhowtodevelopeffectivecoastalprotectionsinfuture.Theseguide-linesand lessonswerecollectedfromnumerous literatureswithinthePacificregion.TheapproachedusedtocollecttheseimportantknowledgewerethroughpostingandsharingofviewsinthePacificsolutionexchangenetworkhostedbyUNDPandobtainingrelevantinformationfromSOPAClibraryandliteraturesearchthroughUSPlibraryandGooglesearch.

Thereportidentifiednon-structuralandstructuralcoastalprotectioninterventions.Non-structuralinterventionsinclude-knowledgeofcoastalprocesses,policyonworkingwithnature,retreat,accommodateandprotectap-proach,Environmental Impactassessments framework,Foreshore regulations, Locallymanagedmarineareas,NBSAP,integratedcoastalzonemanagementplans,Adoptridgetoreefapproach,establishedengineeringstan-dardsandbuildingcodes.ExamplesofstructuralinterventionsfoundinthePacificwereMaintaininghealthyreefislandsandislets;protectionandrestorationofseagrassandseaweedsystems;maintaininghealthyfringingandbarriercoralreefs;plantingofmangroves;stabilizingcoastalbeachesandbeachnourishment.Hardstructuresareseawalls,groynes,revetments,gabions,andbreakwaters.

ThereportwasabletocapturesomeexamplesofthesestructuralinterventionsinsomePacificcountries,throughphotographs.

SomeselectedPacificexperiencesweresharedonhardandsoftstructures,biophysicalstructures,coastaladapta-tionmechanism,participatoryapproach,toolsanddesignsandrelocationoptions.


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