2015SimPresentation

1UseofMacrophyteTreatmentSystemsforWaterQualityImprovementinSingaporeC.H.Sim,B.S.QuekandW.J.LuPUBSingapore3rdIWASymposiumonLakeandReservoirManagement(3to7August,2015)2Outline•ABCwatersprogramme•Catchmentapproachinwaterqualityimprovement•Examplesofwetlandprojects•Wetlandplantinginreservoirs•Wetlandplantingingolfcoursesandparks•RiverrestorationprojectatKallangriverBishanpark•Currentresearchareas•Futureresearchareas3•Wehavetotaponallsourcesofwaterwithinthewaterloop/cycle•Today,Singaporecollectswateron2/3ofourlandarea•EachdropofrainwaterfallingonourcatchmentisimportantforwatersupplySingapore’suniqueurbanwaterloop=Singapore’slocalsourcesofwatersupply4IntroductiontoABCWatersProgrammeA.ACTIVENewrecreationalspacesB.BEAUTIFULIntegrationofwaterswithurbanlandscapeC.CLEAN-ImprovedwaterqualityLaunchedin2006totransformSingapore’snetworkofdrains,canalsandreservoirsintovibrantandbeautifulstreams,riversandlakes.ABCwatersmanagementstrategytoapplyatcatchmentlevel5CatchmentApproachinWaterQualityImprovement•Placementofsmalltreatmentunitsinstrategiclocationstointerceptnutrientloads–Differentdiffuseandpointsources–Agricultural,industrial,residentialareas–StagnantwaterareasRestorationofWaterways-Islandwideimplementationofdifferenttypesofnaturalplanttreatmentunits6ABCWatersProgramme:TheBlueMapwithprojectsislandwide•DevelopmentofABCWatersmasterplanandprojectimplementation•Promoteadoptionbypublicagencies/privatedevelopers7StormwaterqualityobjectivesforSingapore•TheperformancetargetsofABCWatersdesignfeaturesaredirectedattheprotectionofurbanwaterbodiesinSingapore.•ItisdesirablethatnewdevelopmentsincorporateABCWatersmanagementstrategiesthataddresstheimpactofthedevelopmentsonthewaterthatflowsintoourwaterwaysandreservoirs.PollutantStormwatertreatmentobjectivesTotalSuspendedSolids80%removalorlessthan10mg/L(90%ofallstormevents)TotalNitrogen45%removalorlessthan1.2mg/L(90%ofallstormevents)TotalPhosphorus45%removalorlessthan0.08mg/L(90%ofallstormevents)8ABCwatersdesignfeaturesVegetatedSwalesVegetatedswalesremovesoilparticlesandconveystormwaterviaoverlandflowandmildslopes.Bioretentionswalesarevegetatedswaleswithtemporaryponding(extendeddetention)tofacilitateinfiltration.Sedimentationbasinsarepondsthatprovidetemporaryretentionandareductionofstormwaterflowvelocitytopromotethesettlingofparticlesbygravity.Cleansingbiotopesareaformofartificiallyconstructedwetlandswithrecirculation.BioretentionSwalesSedimentationbasinsCleansingbiotopeBioretentionBasins/RaingardensBioretentionbasinsarevegetatedlanddepressionsdesignedtodetainandtreatstormwaterrunoff.9WetlandscompletedunderPhase1ofABCWatersProgramme1.AlexandraCanalWetlands–demonstrationof4differentsystems2.GroveDriveWetlands–pilotsiteforsurfaceflowwetland3.JurongLakeFloatingWetland4.PandanFloatingWetland5.SengkangFloatingWetland6.YishunPondFloatingWetlandandMarshland7.LorongHalusWetland–treatmentwetlandwithsubsurfaceflowandsurfaceflowwetlandsSengkangFloatingWetlandGroveDriveWetlandLorongHalusWetlandAlexandraCanalwetlands–demonstrationsiteofwetlanddesignsAquaticplantpondSurfaceflowwetlandSub-surfaceflowwetlandSedimentationpond•LocatedinupperreachesoftheSingaporeRiver.•200mstretchoftheopenwaterwaydeckedovertoconstructwetlands.•Waterispumpedfromthecanalintothewetlandsfortreatmentbyplantsandfiltermedia,thenchannelledtotherockscapegardenandbackintothecanal,eventuallyendingupinMarinaReservoir.11SengkangFloatingWetlandinPunggolReservoirYishunPondFloatingWetlandsPandanReservoirandJurongLakeFloatingWetlandsIntroductionoffloatingwetlandsinreservoirsandstormwaterpondsforwaterqualityimprovementFloatingWetlandSystems12SengkangFloatingWetland•SengkangFloatingWetlandisSingapore’slargestmanmadefloatingwetland(2400m2).•Completedon7Nov2010.•Mainfunctionsaretocleanthereservoirwater,improveaesthetics,andcreatenewspacesforrecreation.•Pedestrianbridgeandfloatingboardwalkwereconstructedtoallowthepublicacloserlookatthewetlandwhileminimizingdisturbancetotheplantsandwildlife.13Plantselection•Thereare8plantedislandswith18,500numbersof18speciesofwetlandplants.•Chosenfortheircleansingandaestheticproperties•Plantsabsorbnutrientandpollutantsthroughtheirroots•TheselectedspeciesincludetallemergentsuchasTyphaangustifolia,Cannaglauca,Cyperusalternifolius,Cyperushaspan,PandanusamaryllifoliusandgroundcoverBacopamonnieri,HydrocotyleasiaticaandIpomoeapes-caprae.14LocalsystembyTropicalEnvironmentPteLtd,Singapore•LocatedbesideKhooTeckPuatHospital,inYishunstormwaterpond.•Pondarea4.8ha,wetlandarea3,000m2,completedinJan2011•Marshlandaroundtheshoresoftenstheedgesofthepondwhiletheaquaticplantsuptakenutrientsinthewater.•Italsoprovidesanaturalhabitatforfishesandbirds.YishunPondFloatingWetlandandMarshland(localdesign)WetlandPlantinginReservoirsandCatchmentsCompetesfornutrientsinthewatertocontrolthegrowthofalgaeandinvasiveweedsImproveswaterqualitybyremovingcontaminantssuchasheavymetalsIncreasestheaestheticsoftheareaLotusconservationsiteCattailsSpikerushHanguanaWaterbananaLudwigiaadscendensbedsKnotgrassPolygonumislandKangkungIpomoeaaquaticaalongtheba