climate change impact assessment 2010 · sca climate change impact assessment 2010 2 executive...

Sydney Catchment Authority

Climate Change Impact Assessment2010

Blue Mountains Catchments

Cooma

Sydney Catchment Authority Drinking water catchments

Pumping station

Canals and pipelines

Prospect WaterFiltration Plant

SCA’s drinking water catchments

Uppe

r Can

al

Pipelines

Braidwood

Canberra

Shoa

lhav

en River

Goulburn

Nowra

Wollongong

Lithgow

Sydney

Wollondilly River

Bendeela PondageLake Yarrunga

Nattai River

Nepean River Woro

nora River

Haw

kesb

ury R

iverCoxs River

ProspectReservoir

WarragambaDam

WoronoraDam

TallowaDam

Fitzroy FallsReservoir

WoodfordDam

Greaves CreekDam

MedlowDam

CascadeDams

CordeauxDam

Broughtons Pass Weir

Pheasants Nest Weir

AvonDam

NepeanDam Cataract

Dam

Bowral

WingecarribeeReservoir

Katoomba

Kowmung R

iver

LakeBurragorang

Wingecarribee River

Dam

Crookwell

ContentsExecutive summary 21 Introduction 6 2 Climate change projections 7

2.1 ClimateprojectionsforSydneyregion 9

2.2 Climatescenariosusedinthisstudy 10

3 Mitigation strategies 124 Climate change hazards and impacts 135 Adaptation 14

5.1 Toolsandsystems 15

5.2 Waterquantity 16

5.3 Waterquality 17

5.4 Environment 18

5.5 Landuse 19

5.6 Infrastructure 20

5.7 Supplychain 22

5.8 Business 22

5.9 Regulationandrelationships 24

6 Conclusion 26 References 27Acronyms 28Contact information 30

SCAClimateChangeImpactAssessment2010

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Executive Summary Changesinclimaticconditions–intheformofincreasedclimatevariability,longer-termaverages,alteredrainfalldistributions,increasedfrequencyand/orintensityofextremeweather-relatedevents–arelikelytohavebroad-rangingimplicationsfortheSydneyCatchmentAuthority(SCA).AcomprehensiveclimatechangeimpactassessmentcompletedbytheSCAin2010hasemphasisedthecomplexityoftheinterrelationsbetweenwaterquantity,waterqualityandcatchmentcondition,andhighlightedthepotentialimpactsofclimatechangeonSCAoperations,infrastructure,businessandregulation.

TheclimatefuturesusedinthisassessmentarebasedonrecentclimateprojectionscoveringSCAcatchmentareas.Projectionsoffutureclimatehavelargeuncertaintiesbecausecurrentmodelsareunabletocapturethecomplexityoffeedbackmechanismsintheearth-atmosphere-hydrospheresystem.Althoughthescienceofclimatemodellingisrapidlyimproving,modelsandprojectionsatbestpresentarangeofpossiblefuturestoconsiderinscenarioandbusinessplanning.SuchknownuncertaintyrequirestheSCAtobeadaptabletorapidchangeandapplyongoingsustainableandflexiblebusinesspracticestoensureresiliencetochangesinclimateandotherexternalforces.

Theimpactassessmentconsideredtwofutureclimatescenarioswithhighertemperaturesandmorevariablerainfallpatterns,andidentifiedandprioritisedimpactsviaaseriesofstructuredinternalworkshops.GroupsofSCAspecialiststhenidentifiedcurrentactivitiesorcontrolsthatpartiallymitigatethepotentialimpacts,andalsodevelopedarangeofresponsesthatcouldbeconsideredinthefuture.Theassessmentfoundthatoverall,theSCAhasahighdegreeofpreparednessformanyofthepotentialimpactsofclimatechange.WaterresourcemanagersinAustraliahavehistoricallyhadtodealwithahighdegreeofclimaticandhydrologicvariability.TheSCAhasidentifiedanumberofbusinessareaswhereimprovedplanning,additionalinvestmentandback-upsystemscouldassistinbuildingadaptivecapacityandbusinessresilience.

Itwasnotedthatexternalforcessuchaspopulationgrowth,changesingovernmentpolicyandinvestmentinsourcediversificationforpurposesotherthanclimatechangemayimpactontheSCAsoonerthanclimatechangeitself.

Theimpactassessmentfoundthatadditionalinvestmentsininfrastructure,modelling,toolsandpreparednesswouldassistinbuildingadaptivecapacityandbusinessresilience.ScenarioexercisesbasedonarangeofclimateandpopulationprojectionswouldinformstrategicplanningandpreparetheSCAforexpandedbusinessopportunities.ThefindingsoftheassessmenthavealreadybeenbuiltintotheSCA’sbusinessplanningaspartoftheCorporateSustainabilityStrategythatprovidestheSCA’sstrategicdirectionforthenextfiveyears.


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Climate change actions

Action 1 – Ensuring climate change scenarios are realistic TheSCAwillworkwithothergovernmentagenciesandresearchproviderstoexpandandimproveclimatemodellingtoencompassabroaderrangeofclimatescenariosandsimulatemulti-yearclimaticfluctuations.

Althoughthescienceofclimatemodellingisimprovingrapidly,modelsandprojectionsatbestpresentawiderangeofpossiblefuturestoguidebusinessplanning.Currentprojectionsoffutureclimatescenarioshavelargeuncertaintiesbecauseofchangingestimatesonemissionlevels,differencesbetweentheglobalclimatemodels,problemsinthesimulationofrealisticfloodanddroughtcycles(hydrologicpersistence),andtheinabilityofcurrentclimatemodelstocapturethecomplexityoffeedbackmechanismsintheearth-atmosphere-hydrospheresystem.

Action 2 – Reducing the SCA’s carbon footprint TheSCAwillcontinuetoinvestigateandimproveenergyefficiency,expandhydroelectricgenerationandassessthebusinessbenefitsofcarbonoffsetsaspartofitssustainabilitystrategy.

Muchattentionisbeingplacedonthedevelopmentofadaptationstrategiestodealwiththeimpactsofclimatechange.Thereisstilltheopportunitytoinfluencethedirectionandmagnitudeoftheoutcomesbyreducingthescaleofgreenhousegasemissions.

Action 3 – Quantifying the impact of climate change on water quantity and quality TheSCAwillreviewitsexistingmodelsaswellasanewgenerationofsoftwaretoassesstheirperformanceunderclimatechangescenarios.

TheSCAreliesheavilyonpredictivemodelsandanalyticaltoolstoinformcatchmentandreservoirmanagementdecisionsandearlywarningsystems.Achangingclimatewillchallengethevalidityofmanyofthesetools,asitmaydriveeventswhicharebeyondourhistoricalexperienceandthereforeoutsideofthecalibrationrangeofourexistingmodels.Asclimatechangeislikelytofundamentallyalterpreviouslyassumedlandandwaterrelationships,morerigorouscalibrationsandtestingofthemodelsisneededunderavarietyofclimatechangescenarios.

Action 4 – Increasing flexibility in the water supply systemTheSCAwillinvestigateincreasingtheflexibilityinthewatersupplysystem,includingincreasedcapacitytotransferwaterbetweendifferentpartsofthesupplysystem.

GreaterflexibilitywouldsignificantlyenhancetheSCA’sabilitytocopewithprojectedchangesinthedistributionofrainfall(wetterincoastalanddrierininlandpartsoftheSCAcatchments)aswellasincreasedwaterqualityrisks(egincreasedriskofcyanobacteriabloomscausedbylongerdroughtperiods,highertemperaturesandmoreintensiverainfallevents).


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Action 5 – Improving SCA’s capacity to monitor short-duration eventsTheSCAwillincreasetheemphasisonevent-basedsampling,offsetbyreducedeffortinroutinesampling.Mostclimatechangeprojectionsareindicatingincreasedstormactivityandhighintensityrainfallinsummerbetweenextendeddryperiods.Thisislikelytoresultinmorerapidandmoreextremechangesinwaterquality,andmorecomplexbehaviourshiftsinreservoirhydrodynamics.Monitoringofextremeevents(bothverylowandveryhighflows)hasalwaysbeenchallengingandyetwillbecomeevenmoreimportantasthisdataisneededtohelpimprovemodellingcapabilitiesandcalibrations.

Action 6 – Reviewing strategies and plans for sensitivity to climate change scenariosTheSCAwillreviewitscorporatestrategiesandplansofmanagementtoensuresensitivitytoclimatechangescenarios.

Climatechangesarelikelytohaveabroadimpactoncatchmentandstreamhealth,andontherelativecontributionsofpollutantsacrossthedifferentsources,andacceleratechangesinlanduseandregionaldevelopment.EvaluationoftheimpactoflandusesandtheinterventionsimplementedthroughtheHealthyCatchmentStrategyarelikelytobeconfoundedbyclimatechanges,whiletheplansofmanagementforSpecialAreasshouldbeexpandedtotakeintoaccountclimatechangeimplications.

Action 7 – Reviewing design specifications of existing critical infrastructureTheSCAwillinstigateanongoingprogramforthereviewofdesignspecificationsofexistinginfrastructure,plantandequipmenttoassessitsvulnerabilitytoextremeeventssuchasstorms,firesandfloods.

AchangeinrainfallpatternsandmoreseverestormeventscouldimpactawiderangeofSCAinfrastructure,includingcriticalcontrolsystemsatdams,pumpingstations,controlstructuresandmonitoringandtelecommunicationssystems.Morefrequentand/orhigherintensitybushfirescanalsothreateninfrastructure.

Action 8 – Building explicit consideration of climate change into new business initiatives and project designsSCAwillembedconsiderationsrelevanttoclimatechangeintoitsplanningandbusinessprocesses.TheSCA’ssustainabilityframeworkhasopportunitiestoalignclimatechangeresiliencewithforwardplanning.Climatechangeimpactsonsupplyandwaterqualitywillincreasetheneedtojustifyprojectexpenditureaswellasputpressureonrevenues.SCAbusinesscases,whicharealreadyrequiredtoincludesustainabilitycriteria,shouldaddressclimaterelatedrisksanddemonstratetheirpotentialtoimprovebusinessresilience.Businesscasesshouldalsoexplorealternativefundingoptionsandeconomicmodels.

Action 9 – Increasing preparedness to manage concurrent or extreme incidentsTheSCAwillimproveitsworkforce’sadaptivecapacityandresponsivenessbyinvestinginskillstrainingandprofessionaldevelopmentforitsstaff.Preparednessformanagingextremeorconcurrentincidentsisabusinessreality.

Highertemperatureandmoreseverestormsarelikelytoleadtoanincreaseinthenumberandcomplexityofdeclaredincidents.Duringaconcurrentorextremeincidentkeyinfrastructurewouldchallengeoperatingproceduresandorganisationalresilience.TheSCA’sincidentresponseandscenario-basedcontingencyplanningarewelldeveloped.TheSCAwillincreaseitsattentiontoincidentmanagement,businesscontinuityanddisasterrecoveryplanningtoensurethatSydney’srawdrinkingwaterismanagedtointernationalbestpractice.

Action 10 – Improving communication and knowledge exchange on climate change TheSCAwillbeproactiveincommunicatingwithcatchmentcommunitiesandthebroaderSydneycommunityregardingtheimpactsofclimatechange.

Changesinsecurityofsupply,watersourcemanagementandwaterqualityresultingfromclimatechangecouldimpactonpublicconfidenceintheSCA’sabilitytodeliverreliablequalitywater.Neworexpandedoutreachprogramswillbeneededtomanagecommunityexpectationsofwaterqualityandsupplyissues.

Adaptingtoclimatechangewillrequirechangesinlandpracticesandprobablycatchmentdevelopmentcontrols.TheSCAwillneedtosupportlocalcouncilsandlandholderstounderstandthechangingcircumstancesandtheimpactsonwaterandtheenvironment,andprovideassistanceinmakingtherequiredchangestolegislationandbestmanagementpractices.


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1 IntroductionClimate change challenges the traditional assumption that past hydrological experience provides a good guide to future conditions 1

ThewatersupplysystemmanagedbytheSCAanditspredecessorshasdevelopedinresponsetothevariableclimateoftheSydneyregionandsteadypopulationgrowth.TheMetropolitanWaterPlan(MWP)2004andsubsequentrevisionscompriseanadaptive,integratedapproachtowatermanagementthroughacombinationofdiversificationofsupplyanddemandmanagement.AcollaborativestudyontheprojectedimpactofclimatechangeonsupplyanddemandhasbeenundertakenundertheauspicesoftheMWP.However,risksimposedbyclimatechangearemuchwiderthancoveredintheMWPstudy,inparticularwithrespecttolanduse,waterqualityandinfrastructure.SydneyWaterhasconductedaclimatechangeriskassessmentofitsoperations(SWC,2008),ashaveotherutilities.AlthoughmanyoperationalareasoftheSCAhaveimplicitlyconsideredtheeffectsofclimatechangeandvariabilityintheirbusinessplans,thisefforthasnotbeencoordinatedorupdatedwiththelatestclimateprojections.

ToassessthebroaderimplicationsofclimatechangeontheSCA,acomprehensiveclimatechangeimpactassessmentwasconductedbetweenAugust2009andFebruary2010.Theassessmentinvolvedaseriesofworkshopswith30seniorstafffromacrosstheorganisation,precededbyseminarsonthescienceofclimatechange.TheworkshopsweredesignedtoassessthecurrentunderstandingofclimatechangewithintheSCA,determineclimateassumptionsbuiltintooperationsandplanning,andexplorethesensitivityofbusinessoperationstoprojectionsofclimaticextremesthatlieoutsidethosepreviouslyexperienced.

About1000potentialimpactswereidentified,andlaterconsolidatedinto171hazardandimpactstatementsinninecategories:waterquantity,waterquality,toolsandsystems,infrastructure,environment,landuse,supplychain,business,andregulationandrelationships.FocussedworkshopswithkeystafffromSCAbusinessunitsthenreviewedtheclimateimpacts,assessedcurrentcontrolsanddevelopedarangeofmanagementactionsthatcouldreduceanypotentialclimateimpacts.


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1 Climate Change and Water, Intergovernmental Panel on Climate Change, 2008, 192 pp

2 Climate change projections

TheIntergovernmentalPanelonClimateChange(IPCC)wassetupbytheWorldMeteorologicalOrganizationandtheUnitedNationsEnvironmentProgrammein1988tosummariseandassessthevastarrayofpeer-reviewedscientificliteratureonclimatechange.TheIPCCpublishedassessmentreportsin1990,1995,2001and2007.Tostandardiseassumptionsofgreenhousegasesforclimatemodelling,theIPCCpreparedaseriesoffutureemissionscenariosforuseinthethirdandfourthassessments.

TheFourthIPCCAssessment(IPPC-4),Climate Change 2007,isthemostdefinitiveintermsoflinkingobservedclimatechangetoanthropogenic(human-induced)generationofgreenhousegases.AnIPCC2008technicalpaper,Climate Change and Water,focusesontheimpactofprojectedclimatechangeontheworld’sfreshwatersystems.

Implicationsofthe2001IPPC-3findingsforAustraliaweresummarisedinClimate Change in Australia,publishedin2007(CSIRO,2007a).AreasmostatriskwereidentifiedastheMurray-DarlingBasin,GreatBarrierReefandsouthwestWesternAustralia,withbroad-scaleprojectionsincludinga40%higherchanceofdroughtineasternAustraliaby2070.

TheNSWGreenhouseOffice,nowpartoftheDepartmentofEnvironment,ClimateChangeandWater(DECCW),commissionedCSIROtoassessprojectedchangesinaverageclimateandclimateextremesforNSWoverthenext70yearsbasedonmodellingoutputsfromthe2007CSIROstudy,whichinturnwasbasedonthe2001IPPCassessment.AseriesofindividualreportsontheimpactofclimatechangeforindividualCatchmentManagementAuthoritiesinNSWwerealsopublished(CSIRO2007b).Theseprojectionsarebasedon200kmgridcellsandareunabletoprovidetheresolutionneededforregionalstudiesrequiredbytheSCA.

In2009DECCWcommissionedtheUniversityofNSWtodevelopregional-levelclimaticprojectionsoftemperatureandrainfallfornineStatePlanregionsofNSWfortheyear2050.TheNSW Climate Impact ProfileformspartofAction in a Changing Climate(CCAP)whichdescribesactionstobetakenoverthenextfiveyearstorespondtothechallengeofclimatechange.Theprojectionsarebasedonamodellinggridsizeof200kmto300kmwithinterpolationdownto50kmx50km,andhavehighuncertaintiesaroundcoastalregions.

TheconsensusofclimatescientistsisthatmanyareasofAustraliaarealreadyshowingevidenceoftheeffectsofclimatechange,forinstancedecadesofreducedrainfallandrunoffintheMurray-DarlingBasinandsouthwestWesternAustralia.TheunprecedentedhightemperatureswhichcontributedtotheseverityoftheFebruary2009bushfiresinVictoriawasalsoaclearclimatechangesignal.HoweverthedatafortheSydneyregionismoreequivocalandaveragerainfallhasnotbeentoodifferentfromlong-termaverages.ItisinstructivetonotethattheclimateinSydney’scatchmentareasisinfluencedbyinteractionsbetweensoutherncirculationpatternsdrivenbytheSouthernAnnualMode(SAM)overAntarctica,IndianOceanseasurfacetemperatures,andnortherncirculationpatternsmorecloselycorrelatedwiththeElNiñoSouthernOscillation(ENSO).Thisinteractionismorecomplexthanclimatedriversinthenorthorsouthofthecountry.Note,also,that SCAClimateChangeImpact

Assessment2010

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rainfallismoredifficulttomodelthanotherclimaticparameterssuchasairpressureandtemperature.

ThemostrecentIPCC-4reportisbasedonpeer-reviewedscientificpapersthatarenowatleastfiveyearsold.Themostrecentscientificdataindicatesthatgreenhousegasemissionsandglobalwarmingobservationsaretrackingonorabovetheworse-casescenarioconsideredbytheIPCCinits2007report.

Regional climate modelsTheclimateprojectionscontainedintheIPCCreportsarecalculatedusinglarge-scalethree-dimensionalmodelswithgridcellsof200kmto300km.Moredetaileddownscaledmodelsarerequiredtomodelclimateonthefinerscalerequiredforwatersupplyplanningatacatchmentlevel.Suchmodelsarecomplexandrequirelargeamountsofcomputingpower.

ModellingrecentlyundertakenbytheCSIROandUniversityofNSW(NSWOfficeofWater,2010)fortheSCAaspartoftheclimatechangesupply-demandcomponentoftheMWPisdownscaledtoa4kmgridsizewhichbettercaptureslocaltopographicandmesoclimateeffects.

Limitations in climate modellingClimateprojectionsarepresentedasarangeordistributionofpossibleclimates–temperatureandaverageorseasonalrainfall–thatareplausibleunderfuturegreenhousegasscenarios.

Oneofthedangersinusingtheoutputsfromclimatemodelsistheadoptionofunrealisticexpectationsoftheaccuracyorcertaintyoftheclimateprojections.Evenwhenrangesformodelrunsaregiven(egtemperaturesvaryfrom+0.2°Cto+5.6°C),thereisanatural,butincorrect,tendencytoassumethecentralvalueas‘mostlikely’.

Moreimportantly,globalclimatemodelscannotyetreproduceinter-decadalcyclessuchasdrivenbyENSOevents,andcannotreproducemulti-yeardroughtsandextendedperiodsofhigherrainfall.Consequently,mostrunoff/yieldstudiesmakeassumptionsinthedegreeofyear-to-yearcorrelation,or‘persistence’infutureclimates.IntheMWPSydneystudyitisassumedthatthefuturepersistenceissimilartothatobservedinthehistorical(100-year)recordintheabsenceofmoreappropriateclimatemodels.Theresultant‘systemyield’isstronglydependentontheassumedpersistence.

Climate extremes and variabilityAtalocallevel,itisdifficulttodistinguishbetweenclimatevariabilityandclimatechange.Inareassuchassouth-easternAustralia,naturalclimatevariabilityexhibitswidefluctuationsyear-to-yearanddecade-to-decadecomparedtolong-termtrendsprojectedinclimatechangescenarios(Figure1).


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Figure 1. Time series of mean annual maximum temperature anomalies in NSW between 1950 and 2003. The red and blue bars are percentage of NSW in the top (hot - red) and bottom (cold - blue) deciles compared to the average between 1961 and 1990 (from Climate Change in New South Wales: Hennessy et al, 2004a).

2.1 Climate projections for Sydney regionThemostdetailedclimatestudyatthescalerequiredbytheSCAistheClimate change impacts on water supply and demand in Sydney(NSWOfficeofWater,2010),whichwasconductedaspartoftheMWP.

Examplesofclimateprojectionsfromthisstudyinclude:• Increaseinrainfallandstreamflowinmetropolitancatchments.• ReducedrainfallandstreamflowinWarragambaandShoalhaven

catchments.• Increaseinsummerrainfallduetostrongeronshoreairflows,slight

decreaseinwinter.• Numberofdaysofextremerainfall(>40mm/day)increasesby45%in

summer.• Increaseinfrequencyofcontinueddryspells(15daysormore).• Doubleinfrequencyofhot(>32°C)andveryhot(>37°C)days.• Evaporationincreasesby10%withdoublethenumberofveryhigh

evaporationdays.

Themostseriouslimitationsofthisstudyarethatresultsarebasedonasingleglobalclimatemodel,andtheassumptionthat‘persistence’(year-to-yearcorrelation)issimilartothehistoricalrecord.

OtherstudiesrelevanttotheSCAcatchmentareaincludeRainfallextremesunderclimatechangeconductedbytheCSIROfortheSydneyMetropolitanCatchmentManagementAuthority(CMA)andpartners(Abbs,inprep),andNSWClimateImpactProfile(DECCW,inprep).ThesestudiesontheanticipatedeffectsofclimatechangeineasternNSWandlocallyintheSydneyregiondemonstratethewidescatterinclimaticvariablesthatarisefromclimatemodellingandtheinherentuncertaintiesinclimateprojections.


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TheSCA’ssystemyieldprojectionsarebasedonhistoricalhydrologicalrecordswhichareunrepresentativeunderclimatechangescenarios.Ontheotherhand,currentprojectionsoffutureclimatescenarios(includingrecentclimatemodellingundertakenfortheMWP)aresubjecttolargeuncertaintiesforanumberofreasonsincluding:• inabilitytosimulaterealisticfloodanddroughtcycles(hydrologic

persistence)• changingestimatesonemissionlevels• differencesbetweentheglobalclimatemodels• inabilityofcurrentclimatemodelstocapturethecomplexityoffeedback

mechanismsintheearth-atmosphere-hydrospheresystem.

AmajorknowledgegapexistsontheevaluationandselectionofclimatemodelsanddownscalingtechniquesfortheSCAcatchmentareas.AsingleclimatemodelwasusedintheMWPclimatestudy,andthemodeloutputscouldnotsimulatemulti-yearcorrelations(persistence)ofdroughtandrainperiods.Asclimaticmodellingtoolsarecontinuallyimproving,thiswilllikelybeanareaofongoingresearcheffortfortheSCA,workingwithotheragenciesandindustrybodiesasappropriate.

Althoughthescienceofclimatemodellingisimprovingrapidly,modelsandprojectionsatbestpresentawiderangeofpossiblefuturestoguidebusinessplanning.

Climate Change Action 1 – Ensuring climate change scenarios are realistic

SCA Corporate Sustainability Strategy key focus area: Stakeholder relationshipsTheSCAwillworkwithothergovernmentagenciesandresearchproviderstoexpandandimproveclimatemodellingtoencompassabroaderrangeofclimatescenariosandsimulatemulti-yearclimaticfluctuationsandafocusonyear-to-yeardroughtandrainfallcorrelations.

2.2 Climate scenarios used in this studyTworepresentativeclimatechangescenariosweredevelopedforSCA’sclimatechangeimpactassessment.Eachscenarioisaplausibleclimaticconditionthatcouldariseatsometimeduringthenext50years.Thescenariosaresufficientlydifferenttocurrentclimatetochallenge‘businessasusual’andarewithintherangeofprojectedimpacts.

Scenario1–Warmerandstormier–wasdesignedtoexplorethefullrangeofimpacts,bothinternalandexternal,thatcouldaffecttheorganisationinachangingclimate.

Scenario2–Hot,dryandstormy–ismoreextremebutstillplausible,andwasusedtotestthecompletenessofthelistofimpactsidentifiedinScenario1.


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Scenario 1: Warmer and stormier• Increasingfrequencyofeastcoastlowsbutextendedperiodsofdry

westerlywinds.• Similaraverageannualrainfallbutlongerdryspells.• Heavierrainfallfromstormeventsduringsummer.• Hotterweather,higherevaporationrates.

Scenario 2: Hot, dry and stormy• Clearclimateshift,weathersystemsmovesouth.• MoresevereElNinoperiodsbringmuchhotterweatherandextended

droughts.• IncreaseinTasmanhighsbringsmoreintensebutinfrequentstorm

events.• Coastaldominatedweathersystems,withmorestormeventsinsummer.• Verydryinland.

Temperature Rainfall Evapotranspiration WindIncreaseby3°Conaverage

Similaraverageascurrentclimate,butincreaseinsummerrainfallanddecreaseinwinterrainfall

10%increaseinsummerandspring

Summerpeakwindspeedsincreaseby10%

Highermaximaandhigherminima

Spatialredistribution–morecoastalrainfall

Doublenumberofhighevaporationdays

Heatwaves(>35oC)twiceascommon

Extendeddryspells

Increasednumberofconsecutivedaysoflightrain

Temperature Rainfall Evapotranspiration WindIncreaseaverageby6°C

20%decreaseintotalrainfall,butincreaseinproportionthatfallsinintense,shortbursts

20%increaseinsummerandspring

Peakwindspeedsincreaseby30%

Moreintenseandfrequentheatwaves

Spatialredistribution–increasedcoastalrainfall(metropolitandams)insummerandautumn.DecreaseinShoalhavencatch-ment.Verydryinland

Highermaximumandhighermini-mumtemperatures

Longerdryspells,multi-yeardroughts

3 Mitigation strategies Whilemuchattentionisnowbeingplacedonthedevelopmentofadaptationstrategiestodealwiththeimpactofclimatechange,thereisstillsignificantopportunitytoinfluencethedirectionandmagnitudeoftheoutcomesbyreducingthescaleofgreenhousegasemissions.Mitigationstrategiesareincreasinglyreflectedingovernmentpolicywithresultantimpactsoncarbonpricing,renewableenergytargets,andelectricityandfuelcosts.

Aspartofitssustainabilitystrategy,theSCAisalreadyseekingtoexpanditsuseofhydroelectricityplantstoreduceitsdependenceoncarbonfuelenergy,investigatingimprovementsinenergyefficiencyandinvestigatingbusinessopportunitiesforcarbonoffsets.

Climate Change Action 2 – Reducing the SCA’s carbon footprint

SCA Corporate Sustainability Strategy key focus area: Resource optimisationTheSCAwillcontinuetoinvestigateandimproveenergyefficiency,expandhydroelectricgenerationandassessthebusinessbenefitsofcarbonoffsets.TheenvironmentalfootprintofSCA’sworkforcecouldbeimprovedbytheuseoftele-andvideo-conferencingand,whereappropriate,activeencouragementoftelecommutingandotherinitiativestoreducegreenhousegasemissions.


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4 Climate change hazards and impacts Climatechangeimpactscanbeanalysedatanumberoflevels.Atthehighestlevelaretheprimaryclimaticvariables(egtemperature,rainfall,evaporation,wind)thatleadtoasecondaryhazard(egincreasedbushfires,shortintensestorms)whichwillgeneratearangeofresourceandbusinessimplications(egincreasederosionandturbidity,greaterbushfiredamage).ThefinallevelencompassesmanagementandcostimplicationsontheSCAanditsstakeholders(egagreementswiththeRuralFireService,disruptionstopowersuppliesandtelecommunications,impactsonpublicsafety).


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Primary climatic hazard

• Increasedtemperaturesandtemperaturevariability

• Changesinrainfalldistribution,frequencyandvariability

• Extremeweatherevents–changesinfrequencyandseverityoffloods,fires,highwindsandlightning

Secondary hazard

• Driersoilsleadingtochangesinrainfall-runoffrelationships

• Increasedbushfirerisk

• Highererosionratesincreasesedimentloadandturbidity

• Increasednutrientloadsandmorefrequentalgalblooms

Implications

• Increasedneedforfire-fightingresources

• Interruptionstocommunications

• Electricitydisruptionsandpumpingstationshutdowns


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5 Adaptation Theterm‘adaptation’inthecontextoftheSCAclimateimpactstudyreferstoactionsthatcanbetakenbytheSCAtoincreaseitspreparednesstodealwithclimatechangeimpactsasandwhentheyarise.Theseactionsmustbedesignedtobuildorganisationalresiliencetoincreasedvariability,severityandunpredictabilityofeventsrelatedtochangesinclimate.AdaptationalsoincludesactionsthatcanbetakenbytheSCAtoachievesustainablebusinessoutcomesinresponseto,andinanticipationof,government,economicandsocialchangethatcouldoccurasaresultofclimatechange.Someoftheseactionsarealreadypartofroutinebusiness;othersrequireadditionalinvestmentornegotiationwithexternalagencies.

TheadaptationresponsesweredevelopedthroughaseriesofninefocussedworkshopswherespecialistsinrelevantSCAbusinessunitscriticallyreviewedthepotentialimpactsandidentifiedexistingcontrolsoractionsthatshouldlessenorpartiallyaddresstheimpactacrossninethemeareas:

1. Toolsandsystems2. Waterquantity3. Waterquality4. Environment5. Landuse6. Infrastructure7. Supplychain8. Business9. Regulationandrelationships

Workshopparticipantsalsoidentifiedadditionalactionsorresponsesthatcouldbeconsideredinthefuture,subjecttofurtherfeasibility,riskassessmentandcost-benefitstudies.Participantsthenrankedtherelativeimportance(low,medium,high)ofeachimpactintermsofthepotentialsignificanceontheorganisation.

Thirtypercentoftheimpactswereconsideredhighimportance,withthebalanceequallydistributedbetweenlowandmediumimportance.Thelargestnumberofhighimportanceimpactswasidentifiedintheinfrastructurecategory,followedbyenvironmentandwaterquantity.TherelativerankingswithineachoftheninethemeareasareshowninFigure2.

Figure 2. Climate change impacts grouped into major themes and ranked by relative importance.


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TheninegroupsofcontrolsoractionsweresubsequentlysortedaccordingtothekeyfocusareasintheSCACorporateSustainabilityStrategy,toensuretheactionsareembeddedintheSCA’splanningframework.

Overall,theSCAhasahighdegreeofpreparednessforhandlingmanyofthepotentialimpactsofclimatechange.InpartthisisduetothefactthatwaterresourcemanagersinAustralia(includingtheSCA)havehistoricallyhadtodealwithahighdegreeofclimaticandhydrologicvariability.Thereforearangeofcontrols(operations,policiesorprocedures)andinbuiltflexibilityisalreadyinplace,whichcanbeacceleratedifneeded.However,theSCAhasidentifiedanumberofbusinessareaswhereimprovedplanning,additionalinvestmentandback-upsystemscouldassistinbuildingadaptivecapacityandbusinessresilience.

Thefollowingsectionssummarisetheidentifiedbusinessvulnerabilities,existingcontrolsandpossibleresponsesaccordingtothekeyfocusareasoftheSCA’sCorporateSustainabilityStrategy.

5.1 Tools and systems

Key vulnerabilities• Increaseinflowvariabilityacrossstorages.• LowerinflowsintoWarragambaDamandTallowaDaminShoalhaven.• MoreinflowsintoMetropolitanstorages(Avon,Cataract,Cordeaux,

NepeanandWoronoradams).• Changesintheorigins,amount,andtimingofpollutantloads.

TheSCAreliesheavilyonpredictivemodelsandanalyticaltoolstoinformcatchmentandreservoirmanagementdecisionsandearlywarningsystems.Achangingclimatewillchallengethevalidityofmanyofthesetools.Thisisbecauseclimatechangemaydriveeventswhicharebeyondourhistoricalexperience(andthereforeoutsideofthecalibrationrangeofourexistingmodels),andbecauseclimatechangeislikelytofundamentallyalterpreviouslyassumedlandandwaterrelationships.TheSCAisbuildingimprovedmodelsofcatchmentstreamflowandtransportofpollutantsduringwetweatherevents.Itisalsoundertakingareviewofbothitsexistingportfolioofmodelsaswellasthenewgenerationofmodelsavailableforsimulatingcatchmentrunoff,pollutantinstreamflows,instreamfateandtransportofpollutantsaswellasgroundwater-surfacewaterinteractionsunderclimatechangescenarios.TheSCA’scurrentwatermonitoringreviewisconsideringimprovementstothemonitoringnetworktoensureitcansupportfuturemodellingneeds.


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Climate Change Action 3 – Quantifying the impact of climate change on water quantity and quality

Corporate Sustainability key focus area: Reliable waterTheSCAwillcompleteitsreviewofmodelsincludinganassessmentoftheirperformanceunderclimatechangescenarios.Existingmodellingtoolswillbereviewedforsensitivitytoassumptionsonclimaticparametersandrevisedasnecessary,andsensitivityrunsofthemodelswillbeundertakenunderavarietyofclimatechangescenariostogetherwithmorerigorouscalibrationtoimprovemodelpredictionsunderbothdroughtandextremewetweatherevents.Modelswillneedtobeabletoefficientlyhandlestatisticalprobabilitydatasetsaswellashistoricdatasetsandwherepossible,catchmentandreservoirmodellingwillneedtobemorecloselycoupled.SCA’smonitoringprogramwillbemorecloselyalignedwiththeinputandoutputofitsmodellingtools,sothatmodelscanbere-calibratedasrainfallpatternsandinflowschange,affectingbothwaterqualityandyield.Monitoringofextremeevents(bothverylowandveryhighflows)willbereviewedandintegratedwithimprovedmodellingcapabilitiestoimprovemodelcalibrationsattheextremesandtobetterinformtheassessmentofclimateimpacts.Therewillbeincreasedemphasisonevent-basedsamplingpossiblyoffsetbyreducedeffortinroutinesampling.

5.2 Water quantity

Key vulnerabilities• Decreasedsystemyieldaffectingbothreliabilityandsecurity.• Increaseinflowvariabilityacrossstorages.• LowerinflowsintoWarragambaDamandTallowaDaminShoalhaven.• MoreinflowsintoMetropolitanstorages(Avon,Cataract,Cordeaux,

NepeanandWoronoradams).

Totalcatchmentyieldislikelytodecreaseduetohigherevapo-transpirationandincreasedsoilmoisturedeficit,aswellasincreasedlocalinterceptionofrunoffbylandownersexpandingtheiruseoffarmdamsandgroundwaterbores.Evaporationwillbeanincreasinglyimportantconsideration.ChangesinrainfalldistributioncouldlowerinflowsintoWarragambaandplaceincreasingdependenceontheMetropolitanstorages.

Highertemperaturesandextendeddroughtsincreasetheriskofmajorwaterqualityincidentsinthestorages(egcyanobacterialbloominWingecarribeereservoir)andwillrequiremoreflexibilityaroundalternatesuppliesandtransferoptionsifindividualstoragesaretakenoff-lineforextendedperiods.

TheSCAhasarangeoftoolstoassisttheassessmentandplanningofwatersupplyoptionsunderawiderangeofscenarios.Wathnetsystemmodellingenablestheefficientassessmentofalternatefuturescenarios,depletion


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projectionsandyieldriskstudies.DeepwaterpumpingstationsandgroundwaterreadinesshavebeenextendedaspartoftheMWP.AcaseforexpansionofthecapacitythroughreplacementoftheUpperCanalisbeingdevelopedandothertransferoptionsarebeingconsideredaspartofstrategicsupplyplanning.

Climate Change Action 4 – Increasing flexibility in the water supply system

Corporate Sustainability key focus area: Reliable waterFurtheropportunitiesforincreasingsupplyflexibilityacrossthesystemwillbeinvestigatedincludingenhancedtransfercapabilities,and/orgreaterlocalstorage(surfacewater,groundwaterandpotentiallyabandonedmines)intheMetropolitanandShoalhavensystemstomaintainreliabilityofsupply.

5.3 Water quality

Key vulnerabilities• Higherfrequencyand/orintensityofextremewetweatherevents

increasesthepotentialforlargescalemobilisationandtransportofpollutantstowatersupplyofftakes.

• Morefrequentorlargercyanobacterialbloomsinstorages.• Differentcyanobacterialassemblagewithpotentiallyhighertoxicityor

tasteandodourcompounds.• Reducedresilienceofaquaticecosystems.• Potentialdestabilisationoflakeecosystemsleadingtotippingpointin

biologicalintegrityandemergenceofnewdominant‘pest’species.• Bushfiresandstormscompromisewatermonitoringstations.

Mostclimatechangeprojectionsareindicatingincreasedstormactivityandhighintensityrainfallinsummerbetweenextendeddryperiods.Thisislikelytoresultinmorerapidandmoreextremechangesinwaterquality,andmorecomplexbehaviourshiftsinreservoirhydrodynamics.Large,intensebushfirescouldresultinlargequantitiesofash,phosphorous,nitrogenandorganicmatterbeingwashedintostoragesifheavyrainfellwithinseveralweekstoayearafterthefire.

Anincreaseinextremewetweathereventsmayresultinanincreasedriskofmajorpollutionincidents.Thefrequencyorscaleofcyanobacterialbloomsinstoragesmayalsoincreaseasaresultofthecombinationoflowerwaterlevelsandincreasednutrientloadingduringextremerainfalleventsand/orthemobilisationofnutrientsfromlakebedsediments.Changesinhydrodynamicorchemicalconditionsmayalsofavourtheemergenceofnewdominantcyanobacterialspecieswithgreatertoxicityortasteandodourthanpreviousbloomsandwouldcausemajorproblemswithmanagementandtreatment.


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Monitoringofextremeevents(bothverylowandveryhighflows)hasalwaysbeenchallenging.ExistingSCAmonitoringprograms(waterquality,hydrometricandmeteorological)arenotoptimisedformeasuringshorterdurationandsporadicrainfallevents.Highertemperatureandmoreseverestormswouldlikelyleadtoanincreaseinthenumberandcomplexityofdeclaredincidents.ConcurrentincidentsorcascadingfailuresofkeyinfrastructurewouldchallengetheSCA’soperatingproceduresandorganisationalresilience.

Climatechangesarealsolikelytohaveabroadimpactoncatchmentconditionandstreamhealth,andonregionaldevelopmentpatternsandassociatedlandusechanges,andonthemanagementpracticesadoptedwithinexistinglandusecategories.Thesewillallultimatelyimpactontherelativecontributionsofpollutantsacrossthedifferentsources.TheymayalsoconfoundtheevaluationoftheimpactoflandusesandtheinterventionsimplementedthroughtheHealthyCatchmentsStrategy.Itwillbemoredifficulttoassesstheimpactofcatchmentinterventionswhenwaterqualityobservationsareconfoundedbychangesinclimate,andmoresophisticatedmodellingandevaluationtechniqueswillberequired.

Thewatersupplysystemalreadyprovidesmanagementoptionstohandlewaterqualitychallengessuchasofftakeselection,systemtransfers,alternatesources,on-lineaccesstohydrodynamicandwaterqualitydataandlimitedeventmodellingcapability.TheSCA’sincidentresponseandscenario-basedcontingencyplansarereasonablycomprehensive.Researchandinvestigationsintothecauseandbehaviourofwaterqualityeventscontinuestoaidmanagementpreparednessandtheidentificationofsuitableresponses.ResearchintothecausesandeffectsofwaterqualityincidentsassociatedwithextremewetweatherisbeinggivenpriorityattheSCAandnationally,throughWaterQualityResearchAustralia(WQRA).TheSCAisalsoapartnerinanAustralianResearchCouncillinkageprojectattheUniversityofNewSouthWaleswhichisinvestigatingtheimpactofclimatechangeinSCA’sSpecialAreas.

Climate Change Action 5 – Improving capacity to monitor short-duration events

Corporate Sustainability key focus area: Reliable waterMonitoringofextremeevents(bothverylowandveryhighflows)willbecomeamajorfocusoffuturemonitoringandresearch,particularlyasthisdataisneededtohelpimprovemodellingcapabilitiesandcalibrations.

5.4 Environment

Key vulnerabilities• Lossofwetlands,possiblypermanent.• PotentialdestabilisationofpeatswampandmassinWingecarribee

Reservoir.• Deteriorationofripariancorridors.


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• Reducedresilienceofterrestrialandaquaticecosystemsleadstoirreversiblechangestobiologicalintegrityandemergenceofnewdominant‘pest’speciessuchascyanobacteria,weedspeciesandpestanimals.

• Lesswaterforenvironmentalflows.• Extendedbushfireseasonwithmoreintensefires.• Vegetationcommunitycouldshifttowardsmoredrought-tolerantorfire-

resistantspecies.

Thenaturalenvironmentprovidesawiderangeofecosystemservicestoprotectwaterqualityandbaseflowintostreams.Changesinclimatearelikelytohaveabroadimpactonbothterrestrialandaquaticecology,affectingcatchmentandstreamhealth,biodiversityandenvironmentalcondition.Theremayalsobesecondaryflow-onenvironmentalimplicationsfromchangestoSCAoperationssuchaswatertransferandenvironmentalflows.

TheHealthyCatchmentsStrategy,includingplansofmanagementofSpecialAreas,StateEnvironmentalPlanningPolicy(SydneyDrinkingWaterCatchment)2011(SEPP),bushfiremanagement,riskandoperationalplansareinplaceandaregenerallyflexibleenoughtohandlechangesincatchmentconditions.

ItwillbeincreasinglydifficulttodifferentiatebetweenoutcomesfromactivecatchmentinterventionbytheSCAandenvironmentalandwaterqualitychangescausedbyclimatechange.Increasingly,moresophisticatedmodellingandevidence-basedevaluationtoolswillberequired.

TheSCAshouldworkcloselywithotheragenciessuchasDECCWandresearchproviderstoimproveassessmentofecologicalconditionandenvironmentalstressors.Theongoingdevelopmentofknowledgerelatingtotheimpactoffireonwaterqualitywillneedtobereflectedinrevisionstofiremanagementpolicies.

5.5 Land use

Key vulnerabilities

• Changesinlanduse(egcropandgrazingtypeandintensity)andretirementofmarginalland,displacedcommunities.

• Increaseinlocalwaterextraction(groundwaterandsurfacewater).• Inadequatestormwaterdesignintownshipsandsewagetreatmentplants

(pointsourcepollutants).• Increaseofdiffusesourcepollutants.• Increasedunderstandingoftheroleofbio-sequestration(bothin

improvingsoilcarboncontentandrevegetation)incarbonmarketswillopenopportunitiesforlandownersandtheSCAinalternativelanduses.

Thedemographicsandmakeupoflocalcommunitiesarelikelytochangeasexistingagriculturebecomeslessviableandhobbyfarmsandretirementacreageincrease,particularlyalongtheSydney-Goulburngrowthcorridor.Thisdemandonlocalwatersupplies,combinedwithapossibleincreaseinthenumberandsizeoffarmdamsandlocalretentionstructurestooffsetreducedrainfallininlandareas,willdecreasetherunoffintostreamsandSCAreservoirs.

ModuleswithintheHealthyCatchmentsStrategyshouldincorporatenewclimatescenariosandprojectionsastheybecomeavailable.TheseincludetheNeutralorBeneficialEffect(NorBE)toolkit,theStrategicLandandWaterCapabilityAssessment(SLWCA),andtheCatchmentDecisionSupportSystem(CDSS),aswellasrurallanduseguidelinesandrecommendedbestmanagementpractices,SewageTreatmentPlan(STP)design,andCMAincentives.ItwouldbebeneficialtoupgradeSCAmonitoringprograms(waterquality,hydrometricandmeteorological)sothattheycanmeasureshorterdurationandsporadicrainfallevents,andmodelsimprovedtobetterunderstandtheimpactofchanginglanduseandclimate.

TheSCAshouldbeproactiveinidentifyingandencouragingnewpracticesthatimprovewaterquality,butnotattheexpenseofrunoffandyield.TheSCAcouldpotentiallyexpanditsCurrentRecommendedPractice(CRP)program.

Climate Change Action 6 – Reviewing strategies and plans for sensitivity to climate change scenarios

Corporate Sustainability key focus area: Reliable waterClimatechangewillbeexplicitlyconsideredinfuturerevisionsoftheHealthyCatchmentsStrategy.DecisionsupporttoolssuchastheCDSS,theNorBEtoolkit,andtheplansofmanagementfortheSpecialAreaswillallneedtorecognizeandbeadaptabletotheprogressivechangesinclimate,catchmentresponseandlandusepatterns.

5.6 Infrastructure

Key vulnerabilities• Moreintensestorms,highwindsandlightning,highertemperaturesand

increasedbushfireweather.Criticalsystemfailurefordams,pumpingstations,controlstructuresandotherfacilities(egon-sitepowersupplies,controlsystems,communications,actuators,pumps,watermonitoringstationsandradiotelemetryassets).

• Flood,waterorhaildamagetoSCAinfrastructure(includingtelemetryandcommunicationssystems).

• Watersupplyinfrastructurenotsuitedtochangedinflowpatterns.• FlooddesignbasedonAustralianRainfallandRunoff(ARR)andProbable

MaximumFlood(PMF)estimatesinadequate.• Debrisingatesandofftakes,weirfailure.

AchangeinrainfallpatternsandmoreseverestormeventscouldimpactawiderangeofSCAinfrastructure,includingcriticalcontrolsystemsatdams,pumpingstations,controlstructures,monitoringandtelecommunicationssystems.Morefrequentand/orhigherintensitybushfirescanalsothreateninfrastructure.Regulatoryrequirementsfordamsandweirsarelikelytobereviewedandrevisedunderclimatechangewithpotentialinfrastructureimplications.SCAClimateChangeImpact

Assessment2010

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TheSCA’swatertransfersystemcouldbechallengedbytwopotentialimpactsofclimatechange:• Achangeinrainfallpatterns(eghigherrainfallinmetropolitan

catchments)couldcreateincreasedrelianceontheUpperCanaloritsreplacementforSCAsupplytogreaterSydneyand/orincreasedtransfervolumesbetweenMetropolitandams.

• IncreasedcompetitionfromdesalinationandincreasedsupplyfromtheMetropolitanDamscouldaffectSCAwatertransferoperationstoProspectusingtheWarragambaPipelinewhichiscurrentlyconstrainedbyminimumflowrequirements.

Ananticipatedincreaseinclimaticextremeswillputstressontelecommunicationinfrastructurethatsupportsdatacollectionsystems.Moreintensebushfirescouldresultinfailureofcriticalsystemsatdams,pumpingstationsandcontrolstructures.AchangeinrainfallpatternsandmoreseverestormeventscouldimpactawiderangeofSCAinfrastructure,includingcriticalsystemsatdams,pumpingstations,controlstructuresandtelecommunicationsystems.Morefrequentbushfireweatherandhigh-intensitybushfireswouldhaveflow-oneffectstowaterquality,yieldanddamagetoinfrastructure.Thedesignspecificationsofcriticalinfrastructureshouldbereviewedandthevulnerabilityoftelecommunicationlinksandcriticalmonitoringsitesassessed.Regulatoryrequirementsfordamsandweirscouldbealteredunderclimatechange.Furthermodelingofprobablemaximumfloodsunderrevisedclimatemodelswouldassistinplanningupgradesorchangestooperatingregimessuchaspre-releaseinadvanceofflood.

Designspecificationsaresubjecttoregularreview,andmanycriticalsystemcomponentsincorporateredundancyandareconsideredincontingencyplanning.Improvedemphasisonresiliencetoextremeeventswouldbebeneficial.Damsandweirsmeetcurrentregulatoryrequirementsbasedonhistoricalestimatesofpeakfloodandrainfallintensity.Contingencyresponseplans,conditionmonitoringandearlywarningsystemsareinplace.Thereissomeduplicationofcommunicationssystemsandbackupgenerators.

Climate Change Action 7 – Reviewing design specifications of existing critical infrastructure

Corporate Sustainability key focus Area: Reliable waterAforwardprogramforthereviewofdesignspecificationsofexistinginfrastructure,plantandequipmentwillbedevelopedtoassessvulnerabilitytoextremeeventssuchasstorms,firesandfloods.Scenariotestingofcriticalinfrastructure,vulnerabilityassessmentandincreasingredundancyatcriticalsiteswillalsobeundertakenwhereappropriate.Detailedmodellingofdemand/supplyoptionsandfurthermodellingofprobablemaximumfloodswillbeconsideredtoassistinplanningupgradesorchangestooperatingregimessuchaspre-releaseinadvanceofaflood.


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5.7 Supply chain

Key vulnerabilities• Inabilitytosupplysufficientwatertocustomersasperagreements.• Inabilitytomeetwaterqualityparametersinwatersupplyagreements–

impactonfiltrationplants,publichealth,customerconfidenceandcomplaints.

• Changesincustomerdemandduetochangesinpopulationdistributionandconsumption(seealsoWaterQuantity).

• Increasedelectricitycostsimpactupstreamanddownstreambusinesses.• Decreasedreliabilityofelectricitysupply(moreblackouts)impactabilityto

transferwater.

ChangesinclimaticconditionsandgovernmentpressuretoreducecarbonemissionsarelikelytohaveupstreamanddownstreamimpactsontheSCA,intermsofsuppliersofgoodsandservicestotheSCAaswellasthedeliveryofwatertoitscustomers.SomeofthesechangeswillcreatenewormodifiedriskstotheSCAwhileotherswillpresentopportunities.

Torespondtothesechallengesandopportunities,theSCAwillneedtofurtherutiliseorexpanditsexistingrangeofoperatingprotocolsandformalandinformalprocessesforregularcommunicationwithcustomers,suppliersandotherstakeholders,liaisonthroughgovernmentnetworks,flexiblewatertransferandconfiguration,MWPforecasting,andincidentmanagement.

TheabilityoftheSCAtosupplywaterthroughgravityfeedandtheuseofback-upgeneratorsforcontrolsystemsinsulatestheSCAfromelectricitydisruptionstosomedegree,butthereisaneedtoexpandtheuseofstand-aloneelectricitygenerationandre-engineersomekeysystemsformanual/analoguecontrol.

Increasedfrequencyandseverityofstormsandextremeeventscouldpotentiallydisruptservicedeliveryofcriticalitemssuchasdieselfuel,powersuppliesandsubsequentlyotherservices.Thereisaneedtoimproveunderstandingofsupplychainvulnerabilities.

Anincreasedemphasisontheformalassessmentofvulnerabilityofgoodsandserviceproviderstoenergydisruptionsandotheroutages/unavailabilityofcriticalrequirementswouldbebeneficialinresponsetoclimatechangeaswellasotherexternalforcesoutsideoftheSCA’sdirectcontrolsuchaspopulationgrowthanddistribution.

5.8 Business

Key vulnerabilities• Difficultyinmatchingsupplytodemand.• Lossofsalesquantitywithresultantchangestorevenue,expenditure,

dividendsandfinancecosts.• DecreasedpublicconfidenceinSCAtodeliverreliablequalitywater.• Increaseindisruptionandnumberofdeclaredincidents(egfloods,

declareddroughts,algalblooms);concurrentincidents.• Decisionsupporttoolsarenotabletopredictclimatechangeimpactson


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futureplansandoptions.• Communicationsystems,SCADAcompromised(seealsoInfrastructure).• Businessinvestmentsaresub-optimalunderachangedclimate.

Climatechangehasarangeofimplicationsonrevenuefromwatersales,capitalexpenditureandpumpingcosts,aswellasoncompetitionfromalternativewatersourcessuchasdesalination.Impactsonsupplyandwaterqualitywillincreasetheneedtojustifyexpenditureandputpressureonrevenues,withflow-oneffectstoSCA’snegotiationswithregulatorsandratingsagencies.

Variabilityinsystemyieldcouldbeoffsetbyalternativefinancialinstrumentsandforwardsalescontractstomanagepricerisk.

Financialimpactscouldbemitigatedbymoresophisticatedeconomicmodelling,alternativefinanceoptionssuchasinsuranceforunanticipatedpumpingcostsandalternatebusinessmodelstoenablegreaterdiversificationandflexibilityinsupply.Thereisaneedtoimproveincidentmanagementcapability,businesscontinuityplans,workforceadaptivecapacityandmulti-skillingofstaffforworkplaceflexibility.TheSCAmightalsoconsiderexpandingitsroleinthedeliveryofalternate(outofcatchment)watersupplyschemes.

Climatechangeimpactsonwatersupplyandwaterqualitywillincreasetheneedtojustifyprojectdesignandexpenditure.Businesscasesfornewprojectproposalscurrentlyincludesustainabilitycriteria,butnotclimaticassumptionsorsensitivities.

Climate Change Action 8 – Building explicit consideration of climate change into new business initiatives and project designs

Corporate Sustainability key focus area: Business viabilityEnhancedworkforceflexibilityandorganisationalresiliencewillbedeveloped.Incidentresponseplanswillbeexpandedtoaddressabroaderrangeofscenariosandthedisruptiverisksthroughimprovedcontinuityanddisasterrecoveryplanning.Attentiontoincidentmanagement,businesscontinuitymanagementanddisasterrecoveryplanningwillbeincreased.Otherresponseoptionswillbeexploredincludingforwardsalescontractsandalternativefinancialinstrumentstomanagepriceandsupplyrisk,improvingworkforceadaptivecapacityandresponsivenessthroughup-skillingandculturalchange.

InthefutureallSCAbusinesscases,whicharealreadyrequiredtoincludesustainabilitycriteria,willberequiredtoaddressclimaterelatedrisksanddemonstratetheirpotentialtoimprovebusinessresilience.Businesscaseswillalsoexplorealternativefundingoptionsandeconomicmodels.


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AchangeinclimatewouldhavefundamentalimplicationsforSCAbusiness,affectingsales,competition,customersatisfactionandcommunityconfidence.Climatechangeisbecomingincreasinglyreflectedingovernmentpolicywithresultantimpactsoncarbonpricing,renewableenergytargetsandelectricityandfuelcosts.Improvedmodellingoftheimpactofclimatescenariosandclosecollaborationwithexternalagenciesandongoingreviewofadaptationplansisessential.

Highertemperatureandmoreseverestormswouldlikelyleadtoanincreaseinthenumberandcomplexityofdeclaredincidents.Concurrentincidentsorcascadingfailuresofkeyinfrastructurewouldchallengeoperatingproceduresandorganisationalresilience.

Increasedattentiontoclimatechangeinsupplyplanning,systemmodelling,IndependantPricingandRegulatoryTribunal(IPART)negotiations,CorporateSustainabilityStrategy,businesscontinuitymanagementanddisasterrecoveryplansiswarranted.

Climate Change Action 9 – Increasing preparedness to manage concurrent incidents

Corporate Sustainability key focus area: Business viabilityWhiletheSCA’sincidentresponseandscenariobasedcontingencyplanningarereasonablycomprehensive,increasedattentionwillbepaidtoincidentmanagement,businesscontinuityanddisasterrecoveryplanning.Thiswillalsoconsiderthepotentialforimprovedworkforceadaptivecapacityandresponsivenessthroughupskillingandculturalexchange.

Key vulnerabilities• Unabletomeetcustomerdemandduetoreducedinflowstostorages.• ChangeinfunctionandownershipoftheSCA.• DECCW–changestotheSpecialAreasStrategicPlanofManagement

(SASPoM),bushfiremanagement,licensedpollutercompliance,climatescienceprogram,openorclosedcatchments.

• Regulators(IPARTandothers)–increasedpressuretoquantifyimpactsandjustifyexpenditureonclimateimpacts.

• DepartmentofHealth-revisionstoAustralianDrinkingWaterGuidelines;WaterQualityCharacteristics.

Changesinsecurityofsupply,watersourcemanagementandwaterqualityresultingfromclimatechangecouldimpactonpublicconfidenceintheSCA’sabilitytodeliverreliablequalitywater.AninabilitytomeetwaterqualityparameterscouldimpactonpublicconfidenceintheSCA’sabilitytodeliverreliablequalitywater.Longerdroughtperiods,elevatedtemperaturesandsporadicperiodsofheavyraincouldresultinbreachesofsupplyagreementswithcustomers,requiringre-negotiationandamendmentstorelevantlegislationandsupplyagreements.Longerterm,climatechange


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impactsonwaterqualitycouldbelessofaproblemthanquantity,becauseawiderrangeofcontrolmeasures(sourceandofftakeselection)andtheabilityofcustomerstoupgradetreatmentplants.Impactsonsupplyandwaterqualitywillincreasetheneedtojustifyexpenditureandputpressureonrevenues,whichinturnwillflowthroughtoSCA’snegotiationswithregulatorsandratingsagencies.

SCAhasstrongrelationshipswithstakeholdersandregulators,atbothpolicyandoperationallevels.TheWaterforLifeprogram,coordinatedbetweenSydneyWater,theSCA,theNSWOfficeofWaterandDECCW,provideseffectivepublicoutreach,butcouldbemoreproactiveineducatingthepubliconalternativewatersourcesthatmaybeconsideredinthefuture.TheSCAworkscloselywithIndustry&InvestmentNSWwithitsruralandgrazingoutreachprograms.

ThelegislativeandregulatoryframeworksthatdefineexpectationsoftheSCAarebasedonhistoricallyachievablevaluesofwaterquantityandqualitysuppliedfromSydney’sdrinkingwatercatchmentsandreservoirs.Climatechangewillincreasinglyinfluencerelationshipswithexternalagencies,inparticularDECCWthroughitsCCAP,publiclandsmanagementandscienceprograms.NSWHealthwillcontinuetoplayakeyroleinrevisionstotheAustralianDrinkingWaterGuidelinesandemerginghealthrisks.

Climate Change Action 10 – Improving communication and knowledge exchange on climate change

Corporate Sustainability key focus area: Industry ExcellenceNeworexpandedoutreachprogramswillbedevelopedtomanagecommunityexpectationsofwaterqualityandsupplyissues.Atthesametimeadaptationstoclimatechangewillbeincludedincatchmentdevelopmentcontrolsandbestmanagementpractices.Thoseresponsiblefortheirimplementation,suchaslocalcouncilsandlandholders,willbekeptinformedandassistedtoadjusttheiractivitiesanddecisionsinresponsetoclimatechangeimpacts.

ToavoidtheimpactofclimatechangeoncatchmentcommunitiesandlandownersputtingadditionalpressureontheSCA’sroleinplanning,incentivesandcompliance,toolssuchasCDSS,NorBE,SLWCA,stormwaterandonsitewastesystemmodelswillberegularlyupgradedtoreflectchangingormorevariableclimate.EducationandoutreachprogramsandcloseliaisonwithlocalgovernmentandtheDepartmentofPlanningwilldrivetherequiredchanges.

Pre-treatmentathigh-risksitesandre-negotiationoftheacceptablerangeofwaterqualityparameterswithwaterfiltrationplantoperatorswillbeexploredaspossibleresponseoptions.Opportunitiesforpubliceducationandoutreachonrelativehealthrisksofdifferentwatersources,themanagementofcommunityexpectationsandimprovedpublicpreparednessforpossiblewaterqualityincidentswillbeexplored.

6 ConclusionTheclimatechangeimpactassessmentconductedbytheSCAin2010foundthatoverall,theSCAhasahighdegreeofpreparednessforaddressingmanyofthepotentialimpactsofclimatechange.

TheclimatefuturesusedinthisassessmentwerebasedonrecentclimateprojectionscoveringSCAcatchmentareas,andinvolvedtwofutureclimatescenarioswithhighertemperaturesandmorevariablerainfall.Theassessmentemphasisedthecomplexityoftheinterrelationsbetweenwaterquantity,waterqualityandcatchmentcondition,andhighlightedthepotentialimpactsofclimatechangeonSCAoperations,infrastructure,businessandregulation.

TheassessmentidentifiedandprioritisedpotentialclimatechangeimpactsontheSCA,identifiedcurrentactivitiesorcontrolsthatpartiallymitigatetheimpacts,anddevelopedarangeofresponsesthatcouldbeconsideredinthefuture.Theseresponsesincludeidentifyinganumberofbusinessareaswhereimprovedplanning,additionalinvestmentandback-upsystemscouldassistinbuildingtheSCA’sadaptivecapacityandbusinessresilience.

ThefindingsofthisclimatechangeimpactassessmenthavebeenbuiltintotheSCA’sbusinessplanningaspartoftheCorporateSustainabilityStrategythatprovidestheSCA’sstrategicdirectionforthenextfiveyears.

Projectionsoffutureclimatehavelargeuncertaintiesbecausecurrentmodelsareunabletocapturethecomplexityoffeedbackmechanismsintheearth-atmosphere-hydrospheresystem.Althoughthescienceofclimatemodellingisrapidlyimproving,modelsandprojectionsatbestpresentarangeofpossiblefuturestoconsiderinscenarioandbusinessplanning.SuchknownuncertaintyrequirestheSCAtobeadaptabletorapidchangeandapplyongoingsustainableandflexiblebusinesspracticestoensureresiliencetochangesinclimateandotherexternalforces.


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References

Abbs,D(inprep).ImpactofclimatevariabilityandclimatechangeonrainfallextremesinWesternSydneyandsurroundingareas:DraftreportfortheUpperParramattaRiverCatchmentTrust.

CSIRO,2007a.Climate change in Australia:CSIROTechnicalReport2007,<http://www.csiro.au/resources/Climate-Change-Technical-Report-2007.html>.

CSIRO,2007b,Climate change in NSW catchments,seriesofreportstotheNSWGovernment,<www.environment.nsw.gov.au/climateChange/nswreports.htm>.

DECCWinprep,NSW Climate Impact Profile: The impacts of climate change on the biophysical environment of New South Wales,DepartmentofEnvironment,ClimateChangeandWater,Sydney.

HennessyKJ,PageCM,McInnesKL,JonesRN,BatholsJM,CollinsD,JonesD.2004a.Climate change in New South Wales.Part1:Pastclimatevariabilityandprojectedchangesinaverageclimate/ConsultancyreportfortheNewSouthWalesGreenhouseOffice.Aspendale:CSIROAtmosphericResearch,46pp.

HennessyKJ,McInnesKL,AbbsDJ,JonesRN,BatholsJM,SuppiahR,RickettsJR,RafterAS,CollinsD,JonesD.2004b.Climate change in New South Wales.Part2:Projectedchangesinclimateextremes/consultancyreportfortheNewSouthWalesGreenhouseOffice.Aspendale:CSIROAtmosphericResearch,79pp.

IPCC:IntergovernmentalPanelonClimateChange<www.ipcc.ch/>.

IPCC2008,Climate Change and Water:Bates,B.C.,Z.W.Kundzewicz,S.WuandJ.P.Palutikof,Eds.IPCCSecretariat,Geneva,210pp,June2008,<http://www.ipcc.ch/publications_and_data/publications_and_data_technical_papers_climate_change_and_water.htm>.

MWP,2004,Meeting the challenges: securing Sydney’s water future: the Metropolitan Water Plan.NSWDepartmentofInfrastructure,PlanningandNaturalResources.

NSWOfficeofWater,2010.Climate change impacts on water supply and demand in Sydney(Sydneywaterbalanceproject):NSWOfficeofWaterincollaborationwiththeCommonwealthDepartmentofClimateChange,theDepartmentofEnvironmentClimateChangeandWater,SydneyWaterCorporation,SydneyCatchmentAuthority,UniversityofNewSouthWalesandCSIRO.

Steffen,W,2009,Climate change 2009: Faster change and more serious risks:DepartmentofClimateChange,<http://www.climatechange.gov.au/publications/science/faster-change-more-risk.aspx>.

SWC,2008,Sydney Water infrastructure and operations climate change risk assessment:SydneyWaterCorporation,Dec2008.

AcronymsARR AustralianRainfallandRunoff

CCAP ClimateChangeActionPlan

CMA CatchmentManagementAuthority

CRP CurrentRecommendedPractices

CDSS SCA’sCatchmentDecisionSupportSystem

CSIRO CommonwealthScientificandIndustrialResearch Organisation

DECCW DepartmentofEnvironment,ClimateChangeandWater

ENSO ElNiñoSouthernOscillation

IPART IndependentPricingandRegulatoryTribunal

IPCC IntergovernmentalPanelonClimateChange

MWP MetropolitanWaterPlan

NorBE Neutralorbeneficialeffectonwater

PMF ProbableMaximumFlood

SAM SouthernAnnualMode

SASPoM SpecialAreasStrategicPlanofManagement

SCA SydneyCatchmentAuthority

SCARMS SCA’sReservoirManagementSystem

SEPP StateEnvironmentalPlanningPolicy(SydneyDrinking WaterCatchment)2011

SLWCA StrategicLandandWaterCapabilityAssessment

STP Sewagetreatmentplant

WQRA WaterQualityResearchAustralia


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Contact informationSydneyCatchmentAuthorityPenrithOfficeSydneyCatchmentAuthorityLevel4,2-6StationStreetPenrithNSW2750

Telephone +61247242200 1300SCAGOV(1300722468)

Fax +61247252599

Officehours 8.30amto5pmMondaytoFriday

Website www.sca.nsw.gov.au

Email [email protected]

©SydneyCatchmentAuthority

©StateofNewSouthWalesthroughtheSydneyCatchmentAuthority,2010.Thisworkmaybefreelyreproducedanddistributedformostpurposes,howeversomerestrictionsapply.Seethecopyrightnoticeonwww.sca.nsw.gov.auorcontacttheSCAon1300722468.

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