WAMI Sept 2011 7 - IWA Publishing · 2019. 5. 22. · (2010).However,indailysewersystem managementpracticethementioned strategies,techniquesandtoolsstill ... w .i ap on lec m/dfu

waterassetmanagementI N T E R N A T I O N A L

SEPTEMBER 2011ISSUE 3 � VOLUME 7

PAPERS2 Deveopment of a data filtration

method for strategic dataacquisition in sewerrehabilitation planningFlorian Kretschmer, Hanns Plihal,Daniela Fuchs-Hanusch,Michael Moederl and Thomas Ertl

7 Sustainable asset planning inSydney WaterGreg Kane

10 Adaptation of Norway’s watersupply and sanitation systemsto cope with climate changeSveingung Sægrov and Rita Ugarelli

13 A three waters vision forDunedin, New ZealandDan Stevens, Tracey Willmott andLaura McElhone

17 Integrated planning for waterinfrastructure usingsustainability principlesRob Blakemore

UN stresses need to embraceright to water and sanitationTop UN officials recently stressed theneed to realise the human right to water andsanitation, saying that it is critical to a life ofdignity and also to achieving progress in areassuch as poverty reduction, improving childhealth and combating diseases. AssemblyPresident Joseph Deiss explained to aplenary meeting that achieving the waterand sanitation Millennium Development Goaltargets is ‘fundamental’ to achieving othergoals such as reducing poverty, boostingeducation and child health, and fightingHIV/AIDS and other diseases.UN Secretary-General Ban Ki-moon told the

meeting that the task at hand is to translate thecommitment to provide access to cleanwater and adequate sanitation into action:‘Let us be clear, a right to water and sanitationdoes not mean that water should be free.Rather, it means that water and sanitationservices should be affordable and availablefor all… and that states must do everything intheir power to make this happen.Adding that many governments have

already included the rights to water andsanitation in their constitutions and domesticlegislation, he urged those that have yet todo so to ‘follow suit without delay’.�

Anew Asian Development Bank (ADB)report assessing the private sectorin the Philippines says that effective public-private partnership (PPP) implementationin the country can boost its competitiveness,as it brings better infrastructure quality andtechnical expertise.In the Philippines, PPPs have typically been

shunned by business because of unclear policyand regulatory frameworks, a cumbersome

government approval process, and a lack ofbankable projects, the bank says.Other obstacles, such as controversial

judicial decisions, have also constrained PPPgrowth, the report notes.To encourage partnerships, the government

should improve transparency in projectselection, provide better accounting ofrevenues and expenditures, and have ahigher-profile anti-corruption drive.�

Asian Development Bank report calls forfurther public private partnerships

Research highlights benefits ofwatsan programmePentair in the US has announced the resultsof a multi-year research programme,Project Safewater-Colon, which suggesta holistic, low-cost ‘micro-enterprise’ modelcan effectively establish water and sanitationin unserved regions.The programme was conducted in the remote

district of Colon, Honduras, where nearly all ofthe region’s 350,000 people lived withoutclean water and around 25% lackedadequate sanitation.The work funded the installation of more

than 200 water treatment systems and over10,000 individual sanitation facilities andalso encompassed widespread communityeducation programme to increase awarenessof the importance of safe, clean drinking waterand the connection between good hygienepractices and health.Project Safewater-Colon established a

micro-enterprise business model, where thelocal community owns the water treatmentsystems and users pay their communities anominal fee for potable water.An independent study on Project

Safewater-Colon’s health impact was led byDr Jeffery L Deal, director of anthropologyand water studies for the Center for GlobalHealth at the Medical University of SouthCarolina. He said: ‘This is the first timeconclusive evidence confirms what manyhave assumed for years – that accessto clean, safe water directly reduceswaterborne illnesses.‘This project has demonstrated that

community-based water treatment systemscan be done cost-effectively. Our findingsprovide us with a replicable, immediatelydeployable model to reduce the incidence ofwaterborne disease and save lives.’�

Over the last 40 years about€22 billion ($31 billion)has been invested in constructionand extension of public sewersystems in Austria.Today, theseworks are considered to bewidely accomplished. In the futurethe main focus in urban drainagewill concern rehabilitationactivities to maintain long-termfunctioning and value of sewersystems. Figure 1 shows pipejacking at a sewer rehabilitationsite in Austria.International research already deals

with different aspects of rehabilitation

planning (Milojevic et al., 2005;LeGauffre et al., 2007;Ugarelli et al.,2007;Dirksen and Clemens,2008;Alegre and Covas, 2009).Besidesintegrated rehabilitation planningstrategies, publications mainly focuson conservation of the value ofsewer systems or modelling of pipedeterioration.Several softwareapplications for decision support areavailable.An overview of differentmodelling techniques for sewer deteri-oration is given inAna and Bauwens(2010).However, in daily sewer systemmanagement practice the mentionedstrategies, techniques and tools still

Development ofa data filtration methodfor strategic dataacquisition insewer rehabilitationplanning

Many of the current tools for sewer

rehabilitation planning are too

complex to be applied in practice,

and in Austria for example, no

standardised approach regarding

sewer rehabilitation planning is

currently available, making

comparison between utilities

difficult. In a three-year research

co-operation between universities

and sewer operators, suggestions

for standardising performance

requirements for sewer

rehabilitation are being compiled,

as well as a supporting data

filtration method. In this paper,

Florian Kretschmer, Hanns Plihal, Daniela Fuchs-Hanusch, Michael

Moederl and Thomas Ertl describe the basic idea of the data filtration

method, as well as the first results obtained regarding the definition

of different performance indicators.

Florian Kretschmer, Hanns Plihal andThomas ErtlUniversity of Natural Resources and LifeSciences, Vienna (BOKU), Institute ofSanitary Engineering and Water PollutionControl, Vienna, Austria.Email: [email protected]

Daniela Fuchs-HanuschGraz University of Technology, Instituteof Urban Water Management andLandscape Water Engineering, Graz,Austria. Email: [email protected]

Michael MoederlUniversity of Innsbruck, Unit ofEnvironmental Engineering,Innsbruck, Austria.Email: [email protected]

© IWA Publishing 2011

WATER ASSET MANAGEMENT INTERNATIONAL • 7.3 - SEPTEMBER 2011 • 2

EDITORIAL

Editors

Dr John [email protected]

Professor Stewart [email protected]

Mr Duncan [email protected]

Mr Scott [email protected]

Water Asset Management Internationalis an international newsletter on assetmanagement in water and wastewaterutilities. The focus of the newsletter ison the strategic aspects of this developingfield, providing utilities with internationalperspectives on infrastructure planningand maintenance as they seek to delivercost-effective services to their customers.

Instructions for authors are available at:www.iwaponline.com/wami/default.htm

Papers for consideration should besubmitted to the editors or to:

Catherine FitzpatrickPublishing [email protected]

PUBLISHING

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PublisherMichael Dunn

Water Asset Management Internationalis published four times a year (March,June, April, December) by IWAPublishing. Statements made do notrepresent the views of the InternationalWater Association or its Governing Board.

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ISSN (print): 1814-5434ISSN (online): 1814-5442


waterassetmanagementI N T E R N A T I O N A L

DEVELOPMENT OF A DATA FILTRATION METHOD


DEVELOPMENT OF A DATA FILTRATION METHOD FOR SEWER REHABILITATION PLANNING

seem to be rarely used.According toAna and Bauwens (2007) a possiblereason for the lack of practical applica-tions can be found in the rather rigidand complex architecture of today’stechniques and tools.Additionally,most of these (theoretical) modellingand decision support approachesrequire extensive datasets,which oftenare not available at utility level.Due to the lack of standardised

planning procedures at national levelseveralAustrian sewer operators havestarted to develop ‘in-house’ sewerrehabilitation strategies.Thesestrategies are based on the datacommonly available in sewer practice.However, various planning approachescomplicate the comparison of differentutilities and thus the internal andexternal evaluation of a certainrehabilitation strategy.A standardisedapproach would help solve thisproblem.Additionally, it could serveas a planning guideline, especially forsmall- and medium-sized utilities,which often have not yet undertakenrehabilitation planning.The standard EN 752 (2008)

regarding drain and sewer systemsoutside buildings is considered to be auseful basis for the development of anational perspective regarding inte-grated sewer rehabilitation planning.

Strategic data acquisitionFunctional and performance requirementsAccording to EN 752 (2008) drain andsewer systems have four differentobjectives (public health and safety,occupational health and safety,environmental protection, andsustainable development).Functionalrequirements, 13 in total, ensure thatwhilst taking into account sustainabledevelopment,drain and sewer systemsconvey and discharge their contentswithout causing unacceptableenvironmental nuisance, risk to publichealth,or risk to personnel workingtherein.To enable the evaluation of theperformance of a system it is necessaryto determine measurable performancerequirements.EN 752 (2008) doesnot define any performance require-ments but refers to different nationalorganisations in the countries of theEuropean Union.Today,modern strategies in sewer

operation and maintenance are moreand more demand oriented and nolonger only follow fixed intervals.However, to efficiently managemeasures like demand orientatedsewer cleaning and Closed CircuitTelevision (CCTV) for inspection, theavailability of comprehensive inputdata is imperative.For instance, theanalysis of cleaning protocols can givevaluable information to identify sewersections more or less sedimentation

Pipe jackingat a sewerrehabilitationsite in Austria.Credit:Thomas Ertl.

prone.Based on this informationcleaning intervals can be applied moreaccurately (demand orientated).CCTV inspections do not only deliverinformation about the current state ofthe sewer pipes,but can also be used tooptimise inspection intervals in thedifferent sections of the sewer system(e.g. intensified observation of certainstructural conditions).Due to changingboundary conditions demand orientat-ed intervals have to be adaptedcontinuously.A clear definitionof related data needs,measurableperformance requirements and servicelevels could support and catalysemodern sewer operation and mainte-nance.A standardised approach couldserve as a pattern for sewer operators. Itcould support demand orientatedadaptations of maintenance intervalsand would increase transparency ofdemand orientated measures.Another important task of sewer

operation and maintenance is sewerrehabilitation. InAustria a researchproject dealing with strategic sewerrehabilitation planning is currentlybeing carried out.The duration of theproject is from January 2010 toDecember 2012.The projectconsortium comprises threeAustrianUniversities as well as five of the largestAustrian sewer operators.One majorobjective of the project is to suggestmeasurable performance requirementsand related service levels,which can beused on a national scale in accordancewith EN 752 (2008).On an interna-tional level performance indicators arealready discussed inAshley andHopkinson (2002) as well as in Matos

et al. (2003).Performance indicatorsshall be structured in a rather simpleway and shall only depend on inputdata commonly available or at leasteasily accessible in sewer practice.In a first working step the sewer

operators participating in the projectidentified those functional require-ments quoted in EN 752 (2008) mostrelevant for their daily practice:

• Protection from flooding• Protection of groundwater• Structural integrity and design life• Maintaining the flow• Protection of surfacereceiving waters

• Inputs quality

The sewer operators also defined anadditional functional requirement:minimisation of operational efforts.The next step and the current focus

of the project work is to check theavailability and applicability of existingnational (and international) standardsrelated to the different functionalrequirements mentioned above. If astandard is available and consideredappropriate to a certain functionalrequirement, it can be applied directly.In this way the related performancerequirements (performance indicatorsand service levels) are already definedby the existing standard.If there is no standard available for a

certain functional requirement, theproject team (universities and seweroperators) will work out adequateperformance requirements. In theprocess of compiling representativeindicators, the availability of the needed



input data is brought into focus as well.As a result, a set of SMART perfor-mance requirements will be providedto serve as a basis for a standardisedevaluation of functional requirementsaccording to EN 752 (2008).TherebySMARTmeans that the requirementsformulated are Simple and Measurable.They should beAccepted all overAustria and Relevant for the utilities.Due to increasing standards relating toincrease in prosperity, the requirementsareTime-oriented.Hence,by referringto these requirements, comprehensibleand comparable sewer rehabilitationplanning methods can be adapted.A crucial point related to

performance requirements is theavailability of input data needed todetermine performance indicators.Prior knowledge of input datarequirements is essential for strategicdata acquisition and thus for successfulpractical implementations of certainplanning techniques.

Data filtration methodTo support the practical application ofthe suggested performance require-ments in strategic sewer rehabilitationplanning a data filtration method willbe developed within the currentresearch project.The aim of thismethod is to enhance strategic dataacquisition procedures.As mentionedbefore, according to EN 752 (2008)performance requirements have to bederived on a national level.However, inthis context, from a practical point ofview, two different aspects are ofimportance.On the one hand it isnecessary to know exactly what kind ofinformation is gained from a certainperformance indicator (allocation to acertain functional requirement).Onthe other hand it is essential to havepreliminary information about inputdata requirements for the calculationof a specific performance indicator.Based on this information a seweroperator can decide whether a certainfunctional requirement and thereforeperformance indicator is relevant fortheir current planning process, and asewer operator can assess whether it ispossible to calculate a certain perfor-mance indicator with the input dataavailable.As a consequence,missingdata can be collected systematically.Prior to extensive data collection worka cost-benefit analysis might be advan-tageous.The systematic approach ofthe data filtration method is shown inFigure 1.Functional requirements,service levels (and therefore perfor-mance indicators), evaluation methodsand input data are the cornerstones ofthis method.The data filtration method

comprises a reverse and a forwardapproach.To assess the performance of

a system regarding a certain functionalrequirement,one has to focus on therelated service level.A service level isused to describe the degree of targetachievement (e.g. accordance with thefunctional requirement). It defineswhich performance indicator has to beapplied for the assessment.The way ofcalculating the performance indicatoris given in the evaluation method.Eachevaluation method requires a certainand predefined amount of input data.Thus, the data filtration method willdirectly provide the information oninput data requirements for theassessment of a certain functionalrequirement (reverse approach).Focusing on the available input data,

the data filtration method gives anoverview of the applicable evaluationmethods and thus performance indica-tors and service levels to be derivedfrom the existing input data.The‘derivable’ service levels will giveinformation on which of thefunctional requirements can beassessed directly from the availableinput data (forward approach).For all existing and suggested

performance indicators the inputdata requirements have to be listed.In several cases there will be analogiesin the data requirements.However,a summary of all performanceindicators including the relatedinput data requirements willeventually be available.

First resultsIn the following the first results,regarding the collection and develop-ment of performance indicators relatedto the different functional require-ments, are presented.The functionalrequirements are assigned to the fourdifferent aspects of integrated sewermanagement: structural, hydraulic,environmental and operational perfor-mance (EN 752 (2008)).The detaileddescription of service levels is not partof this paper.One functional requirement

concerns the structural conditionassessment of sewers. Structuralintegrity and design life, amongstother aspects, specifies that sewershave to be maintained to ensurestructural integrity.Sewer inspectionis a common practice to observe thestructural condition of sewers (and to acertain extent the hydraulic andenvironmental condition as well).Today, apart from different national andinternational standards (e.g.RLOOE1992,DWAM 149-2 2006),EN13508-2 (2008) is used as a visualinspection coding system inAustria.Further,EN 13508-2 (2008) willreplace all national standards in the EUcountries in near future.For theassessment of sewer conditions differ-

ent national and international stan-dards are available (e.g. ISYBAU 2006,DWAM 149-3).Most of the currentmethods are already based on the EN13508-2 coding system.Methods forstructural assessment as well as inputdata requirements are given by theavailable standards.Regarding service levels all standards

have four to five structural conditiongrades representing the priority ofsewer rehabilitation measures.However, from a practical point ofview in sewer rehabilitation planning itmight be more appropriate only to usetwo structural condition grades (short-term rehabilitation measures needed ornot). Sewer operators would alsorecommend the implementation ofsome kind of ‘rehabilitation grade’performance indicator includingappropriate service levels to be used incombination with sewer conditiongrade assessment. In this new perfor-mance indicator the design life of asewer pipe might be considered aswell.Matos et al. (2003) present afull listing of performance indicatorsfor wastewater services.Herecertain performance indictorsare related to sewer systemrehabilitation (e.g.wOp21 towOp23 (sewer rehabilitation, renova-tion, replacement in % per year)).Another functional requirement

concerns the hydraulic performance ofsewers.Referring to ‘Protection fromFlooding’,EN 752 (2008) states thatflooding events shall be limited tonationally prescribed frequencies.Matos et al. (2003) define floodingrelated performance indicators (e.g.wOp37 to wOp39 (floodings/100kmsewer*year)). In theAustrian guidelineOEWAVRB 11,flooding frequenciesare already defined and categorisedaccording to local boundary condi-tions (rural areas, domestic areas, citycentres, transport facilities, etc.).Hydrodynamic models have to beadopted to prove compliance withprescribed frequencies.Data require-ments are defined by the appliedmodel.Currently another guidelinedealing with sewer maintenance(OEWAVRB 22) is under prepara-tion. In this guideline five hydrauliccondition grades (service levels) shallbe defined.From a practical point ofview two hydraulic condition grades(compliance or non-compliance withthe prescribed flooding frequency)again seem to be sufficient for sewerrehabilitation planning, as publicpressure to immediately solvehydraulic problems (flooding) is high.Two functional requirements

concern the environmental perfor-mance of sewers.The most reliable wayto confirm‘protection of groundwater’is to test the watertightness of sewer



pipes.Therefore the functionalrequirement ‘protection of groundwa-ter’ is considered to be on a par withthe functional requirement ‘water-tightness’. EN 1610 (1998) and theAustrian standard OENORMB 2503(2004) define all required methods andrelated input data.Currently,bothstandards are being revised.However,EN 752 (2008) states that only newsewers have to be in accordance withtesting requirements of EN 1610(1998).Watertightness of existingsewers shall be in accordance withlocal or national testing requirements.This is a very important point, asconventional tightness testingaccording to EN 1610 (1998) andOENORMB 2503 (2004) is a verydifficult task in operating sewer pipes.Information about the water tightnessof sewer pipes can also be gainedthrough indirect methods such asvisual inspection (optical tightness),quality measurements in the ground-water (residues of pharmaceuticals)and tracer measurements.Fenz et al. (2004) for instance

describe the monitoring of concentra-tions of the anticonvulsant carba-mazepine to quantify sewer leakage.These indirect methods seem to bevery appropriate tools and thus shall bepart of the new national guidelinedealing with sewer maintenance(OEWAVRB 22).Quality and tracermeasurements can be connected withadditional and complex work(groundwater modelling, sampling,etc.), but as a result direct statementsregarding the groundwater quality canbe made.From a work expenditurepoint of view visual inspection toprove optical tightness of sewer pipesseems to be more favourable (exclud-ing water protection areas) as it can becombined with the observation of thestructural integrity.Obviously a highquality of inspection data is of tremen-dous importance.Additional data suchas groundwater level,hydraulicconductivity or type of circumjacentsoil can also support the evaluation

Figure 1Data filtrationmethod – reverseand forwardapproach

process (e.g. risk analysis).Regardingservice levels a two graded scale isconsidered to be sufficient for sewerrehabilitation planning (sewer tightnessconfirmed or not). In Matos et al.(2003) this functional requirement isaddress in performance indicatorswOp30 to wOp33 (inflow, infiltration,exfiltration (m3/km sewer*year)).Regarding the ‘protection of surface

receiving waters’,EN 752 (2008) statesthat surface waters shall be protectedfrom pollution within nationallyprescribed limits. In sewer operationand maintenance (and thus in sewerrehabilitation planning) surface waterswill be mainly affected by combinedsewer overflow (CSO) spills.Thenational guideline OEWAVRB 19(2007) defines operational require-ments (efficiencies) for CSOs.According to wastewater treatmentplant design capacity a minimum shareof the annual wastewater quantity in acatchment has to be conveyed to thelocal treatment plant.To prove compli-ance with the prescribed efficiencyrates,hydrological or hydrodynamicmodels have to be used.Again datarequirements are defined by theapplied model.However, input datawill at least be partially equal to thefunctional requirement ‘protectionfrom flooding’.Regarding servicelevels for sewer rehabilitation planninghere again a two graded scale isconsidered to be sufficient(efficiency constraints met or not).Three functional requirements

concern the operational performanceof sewers.Generally,EN 752 (2008)suggests assessing operationalperformance by the number ofoperational incidents or failures.Thefunctional requirement ‘maintainingthe flow’ is mostly affected by theoccurrence of sewer blockages (sewercollapses, sedimentation, etc.).Therefore,proactive sewer operationand maintenance is the most appropri-ate approach to maintain the flow(periodical or demand orientated). InAustria this approach is considered to

be state-of-the-art. In internationalliterature the performance indicator‘sewer blockages’ is cited (e.g.wOp34(No.of sewer blockages/100kmsewer*year) in Matos et al. 2003).However, inAustria from a seweroperator’s point of view any incidentor failure in sewer operation should beavoided.Sewer operators participatingin the research project have less than0.03 blockages/100km sewer*a.Forthis reason the use of the ‘sewer block-ages’ performance indicator is of onlyvery limited significance.For sewerrehabilitation planning it is mostimportant to know which sewers needthe most maintenance. In this contextthe definition of a novel performanceindicator (including data requirements,evaluation method and service levels)such as ‘operating expense’ could bemore appropriate.With regard to contents it is obvious

that the additional functional require-ment ‘minimisation of operationalefforts’, defined by the projects partici-pants, is mainly related to ‘maintainingthe flow’.As mentioned before,operational activities, such as sewercleaning and sewer inspection, areimportant measures to maintain theproper functionality of the sewersystem. If the work carried out isdocumented appropriately (strategicdata acquisition), essential informationfor sewer rehabilitation planning canbe derived (e.g. cleaning intervals ofcertain sewers, etc.).Regarding the functional require-

ment ‘inputs quality’,EN 752 (2008)states that the quality of non-domesticinputs shall be controlled, so that apartfrom further requirements they do notcompromise the integrity of the pipematerial. InAustria the nationalregulation IEV (2006) providesdischarge and control requirements fornon-domestic wastewater.Allsewer operators are requestedto assemble a register of all relevantdischarges.As certain wastewaterqualities can have negative effectson the fabric of the system,



Visual inspection coding system.EuropeanCommittee for Standardization.Brussels.EN 1610 (1998) Construction and testing

of drains and sewers.European Committee forStandardization.Brussels.Fenz,R,Blaschke,AP,Clara,M,Kroiss,H,

Mascher,D and Zessner,M (2004) Monitoringof carbamazepine concentrations in waste waterand groundwater to quantify sewer leakage.Conference Proceedings 6th InternationalConference on Urban Drainage Modelling,15-17 September 2004,Dresden,Germany.IEV (2006)Verordnung des Bundesministers

fuer Land- und Forstwirtschaft betreffendAbwassereinleitungen in wasserrechtlichbewilligte Kanalisationen (regulation ofwastewater discharge to public sewers).BGBl. IINr.523/2006,Vienna,Austria.ISYBAU (2006)ArbeitshilfeAbwasser –

Planung,Bau und Betrieb von abwassertechnis-chenAnlagen in Liegenschaften des Bundes(Planning, construction and operation ofwastewater infrastructure in properties of theFederal Republic of Germany).Federal MinistryofTransport,Building and Urban Development,Federal Ministry of Defence,Berlin,Bonn.Le Gauffre,P, Joannis,C,Vasconcelos,E,

Breysse,D,Gibello,C and Desmulliez, JJ(2007) Performance Indicators and MulticriteriaDecision Support for SewerAsset Management.Journal of Infrastructure Systems.ASCE.Matos,R,Cardoso,A,Ashley,R,Duarte,P,

Molinari,A and Schulz,A (2003) PerformanceIndicators forWastewater Services. InternationalWaterAssociation,Operations & MaintenanceSpecialist Group.Milojevic,N,Wolf,M,Braunschmidt,S,

Rabe,T and Sympher K-J (2005) KANSAS –Entwicklung einer ganzheitlichenKanalsanierungsstrategie fuerStadtentwaesserungsnetze (KANSAS –Development of an integrated sewer rehabilita-tion strategy for sewer networks).Dr.-Ing.Pecherund Partner Ingenieurgesellschaft mbH fuerSiedlungswasserwirtschaft.Munich.OENORM B 2503 (2004) Kanalanlagen

– Ergaenzende Richtlinien fuer die Planung,Ausfuehrung und Pruefung.Austrian Standardsplus GmbH,Vienna,Austria.OEWAV RB 11 (2009) Richtlinien fuer

die abwassertechnische Berechnung undDimensionierung vonAbwasserkanaelen(Guidelines for the calculation and dimensioningof sewers).AustrianWater andWasteManagementAssociation,Vienna,Austria.OEWAV RB 19 (2007) Richtlinien fuer

die Bemessung von Mischwasserentlastungen(Guideline for the dimensioning of combinedsewer overflows).AustrianWater andWasteManagementAssociation,Vienna,Austria.RLOOE (1992) Richtlinie der OOE

Landesregierung – Zustandserhebung vonAbwasserkanaelen (Guideline of the federal stategovernment of UpperAustria – sewer inspec-tion). Linz.Ugarelli,R,Pacchioli,M and Di Federico,V

(2007) Planning maintenance strategies forItalian urban drainage systems applying CARE-S.Conference Proceedings 2nd Leading EdgeConference on StrategicAsset Management,17-19 October 2007,Lisbon,Portugal.

detailed information aboutnon-domestic discharges cansupport sewer rehabilitation planning.

Conclusions and outlookInternational research is alreadydealing with different aspects ofsewer rehabilitation planning.Severalstrategies, techniques and tools areavailable,but due to their complexitymany of the available approaches arenot applied in practice.InAustria, currently there is no

standardised approach availableregarding strategic sewer rehabilitationplanning.Therefore several seweroperators have developed ‘in-house’strategies.This complicates thecomparison of different utilitiesand thus the internal and externalevaluation of specific rehabilitationstrategies. In a three-year researchco-operation between universities andsewer operators, investigations onstandardised performance requirements(performance indicators and servicelevels) regarding sewer rehabilitation(and maintenance) planning will beworked out.Current project workregarding performance requirementsshows that for functional requirementsregarding the structural, hydraulic andenvironmental performance of sewersystems national or internationalstandards (including performanceindicators, evaluation methods, etc.) areavailable.However, in specific casesadditional and more significantperformance indicators and servicelevels would be appropriate.Regardingthe operational performance ofsewer systems no suitable nationalor international standards exist.Comprehensible strategic sewer

rehabilitation planning requires thedefinition of appropriate structural,hydraulic, environmental and opera-tional service levels and applicableperformance indicators.To support the practical application

of incorporating performance require-ments into rehabilitation planningprocesses, a data filtration methodis derived, in the first stage of thementioned research project.Thismethod shall enhance strategic dataacquisition.A sewer operator shallobtain direct information regarding thekind of input data needed to evaluatethe accordance with a certain function-al requirement (reverse approach), andas well as this an overview shall begiven, indicating which of the func-tional requirements could be addressed,using only the data available (forwardapproach).A standardised approachcould also serve as a planning guidelinefor small and medium-size utilities,which often have not yet begun theirrehabilitation planning.The upcoming project steps

are a further development of theperformance requirements (definitionof performance indicators and servicelevels) according to specific functionalrequirements.Based on the perfor-mance indicators and the requiredinput data, the data filtration methodwill be developed.Subsequently, theapplicability of the method will betested in several case studies in thecourse of the project.�

This paper was presented at Pi2011 –the IWA International Conference onBenchmarking and PerformanceAssessment of Water Services,14-16 March 2011, Valencia, Spain.

AcknowledgementThe work is carried out within theproject INFOSAN (Strategic DataAcquisition for Sewer RehabilitationPlanning inAustria), co-financed bytheAustrian Federal Ministry ofAgriculture,Forestry,EnvironmentandWater Management and theparticipating sewer utilities.Theauthors are grateful for this support.

ReferencesAlegre,H and Covas,DIC (2009)Arehabilitation planning handbook for watersupply infrastructures.Conference Proceedings3rd Leading Edge Conference on StrategicAssetManagement,11-13 November 2009,Miami,USA.Ana,E and Bauwens,W (2007) Sewer

network asset management decision-support tools:a review. International Symposium on NewDirections in UrbanWater Management,12-14September 2007,UNESCO Paris,France.Ana,E and Bauwens,W (2010) Modeling

the structural deterioration of urban drainagepipes: the state-of-the-art in statistical methods.UrbanWater Journal,7(1),47-59.Ashley,R and Hopkinson,P (2002) Sewer

systems and performance indicators – into the21st century.UrbanWater,4(2),123-135.Dirksen, J and Clemens,FH (2008)

Probabilistic modelling of sewer deteriorationusing inspection data.Water Science andTechnology,57(10):1635-41.DWAM 143-2 (1999) Optische Inspektion

– Inspektion, Instandsetzung,Sanierung undErneuerung vonAbwasserkanaelen und–leitungen (Visual inspection – inspection andrehabilitation of sewers).Verlag fuerAbwasser,Abfall und Gewaesserschutz,Hennef.DWAM 149-3 (2007) Zustandserfassung

und –beurteilung von Entwaesserungssystemenaußerhalb von GebaeudenTeil 3:Zustandsklassifizierung und –bewertung(Inspection and assessment of sewer systemsoutside buildings part 3 – condition classificationand assessment).GermanAssociation forWater,Wastewater andWaste,Hennef.EN 752 (2008) Drain and sewer systems

outside buildings.European Committee forStandardization.Brussels.EN 13508-2 (2008) Conditions of drain

and sewer systems outside buildings – Part 2:


SUSTAINABLE ASSET PLANNING IN SYDNEY WATER

SydneyWater is beingchallenged with servicingpopulation growth and cityexpansion while managing theexisting asset base and customerservice in a sustainable manner.Future customer needs, behav-iours and demands will change,and climate change will have aconcurrent impact.TheAustralian water industry

generally has become a leader insustainable asset management throughits strong focus on:• Responding to change andcontinuous improvement

• Investing for the long-term• Understanding risk• Adapting to climate change• Questioning the status quo• Providing superior customer service• Protecting people’s health andenhancing the environment

This paper describes how SydneyWater uses asset planning methods formanaging some of these challenges,and how it has produced two keytypes of asset plans: area plans forgrowth and asset management plansfor the existing asset stock.

Asset planning challengeThe population of Sydney is expectedto grow significantly over the next 20years.During this time,past experi-ence tells us that customer demandsand expectations of services andproducts will undoubtedly change; andmost likely the movement will be inthe direction of being more demand-ing and with higher expectations,underpinned by the desire for andavailability of information aboutservices (for example through the useof data from smart meters).Customersand shareholders will continue to seekefficiencies and value for money. It isexpected that climate change willaffect the (frequency, extent andvariability of) ‘extreme’or ‘abnormal’events, and also will produce anunderlying change in the (day-to-day)operating environment for assets.The assets in the urban water

Sustainable asset planning inSydney WaterAustralian utility Sydney Water has a strong focus on asset management, creating plans

for future growth and management of existing assets. In this article, Greg Kane

discusses Sydney Water’s approach to managing the utility’s assets.

Greg KaneSydney Water, Sydney, NSW, Australia.Email: [email protected]


industry generally have the followingcharacteristics:• Many of the assets are buried and outof sight,which makes visibleassessment of asset integrity verydifficult and costly.

• Water industry assets are generallyexpected to operate over long lives

• Long lead times are required to planand build new water industryinfrastructure

• There is a high degree ofconnectivity between service levelsto customers and prudent assetmanagement practices

Though many of the infrastructureassets have long lives, a greatnumber were built some time agoand are aging.New models forcompetition will change thebusiness operating environment,and a range of suppliers of differentproducts are likely to emerge.Against that backdrop,SydneyWater

is facing two concurrent challenges:existing assets and how to managethem into the future; and building newassets for future services and customers.A sustainability approach is the clear

way forward for theAustralian urbanwater industry.Our industry hasstewardship ofAUS$110 billion(US$115 billion) of assets used toprovide safe clean drinking water andwastewater services to protect andenhance the environment.Education and awareness, and a

strong shift in attitudes, culture and

moral codes for sustainability arealready prevalent and growing in theindustry and the community in gener-al. However,while this is important,wehave decided that it also requires anapproach that more systematicallyincorporates and integrates a sustain-able approach in our planning anddecision making processes.

Discussion and analysisSydneyWater defines assetmanagement as:‘A businessdiscipline for managing the lifecycle of assets to achieve a desiredlevel of service and financial returnwithin an acceptable risk framework.’Most definitions of strategic assetmanagement would indicate that isinherently a sustainable approach.In discussion with its members,

theWater ServicesAssociation ofAustralia (WSAA) has adopted asimilar definition:‘Sustainable assetmanagement is a risk-based processto manage infrastructure to achievethe optimal whole of life cost,which provides a desired level ofservice now,and into the future, takinginto account environmental, economicand social considerations.’The author observes that the ‘future’

view has been consciously included toemphasise the longer-term view andsome sustainability aspects have beenmore explicitly described.SydneyWater’s asset management

policy supports the company’sapproach to sustainable asset manage-

Sydney Water’sdesalination plant.Credit: SydneyWater.



ment. It includes a requirement for theCorporation to implement a set ofprinciples in the development andmanagement of SydneyWater assetsthat include actions to:• Consult with relevant stakeholdersto define requirements for servicedelivery

• Deliver a level of service that drivescustomer and stakeholdersatisfaction and willingness to pay

• Consider both asset and non-assetsolutions before settling on theproposed approach

• Pursue lowest whole of life costsat an agreed level of risk indelivering the services

• Apply a triple bottom line approachto life cycle costs, including theexternalities of social, environmentaland economic impacts

• Use SydneyWater’s SustainabilityPlanning Manual in decisionsrelating to sustainable planning

• Apply agreed management practicesthroughout an asset’s lifecycle forinformed decision making

The asset planning processSydneyWater’s asset planning process isillustrated in Figure 1.The first step is to understand the

requirements of customers, sharehold-ers, stakeholders such as interestgroups, the community in general andits regulators.One of SydneyWater’smajor regulators is the IndependentPricing and RegulatoryTribunal(IPART) that assigns an operatinglicence for the Sydney region and thenmonitors performance against it.IPART also determines the prices thatmay be charged to customers.ForSydneyWater many of the company’sservice expectations are reflected andcaptured in the operating licence andin the associated customer contractwith each of our customers (forexample, levels of service in relation todiscontinuity of potable water supplyservices, and for the water pressureprovided to customers).Other servicelevels set by regulators include waterquality related requirements by theDepartment of Health, and environ-mental outcomes set in system licencesby the Department of Environment,Climate Change andWater (on matterssuch as the quality of treatment plantoutputs and frequency of sewageoverflows).Beyond regulation,SydneyWater researches customer demands toestablish levels and standards of service.This step also includes action totranslate those requirements intopotential ‘specifications’ for assets.Atthis stage (of the planning process) notall of the requirements are setand agreed,but will be comparedagainst the capability of theorganisations asset systems.

The assessment of asset capabilityincludes monitoring in the currenttimeframe and more importantly intrends for parameters such as condi-tion, performance, and capacity.Theassessment of the asset system is notonly the asset themselves, but themanagement and enabling systems thatsupport it e.g., people management,financial management, risk manage-ment, logistics, and IT and qualitymanagement systems.The above steps inform the estab-

lishment of the service levels.Thesemay be set by regulatory direction,orcollaboratively by negotiation, consul-tation or internal decision-making.The life cycle strategy for the asset

(types, groups and / or systems) is thendeveloped from a comparison andassessment (trade-off) of the require-ments of various stakeholders and thecapability of SydneyWater.This will bea trade-off of lowest life cycle cost, riskand customer levels of service.So, forlarge water mains where the conse-quence of failure may be significantcommunity impact, costs to the utilityand disruption to customers’ service, anavoid fail or preventative approach isidentified.Conversely, for some smallmains where the impact of failure islow and asset systems are in place forrapid response, rectification andminimisation of consequences andimpact then a run-to-fail (or plan torepair) approach is a more appropriatelife cycle strategy.This analysis then provides the basis

for estimating the resourcing needs tocontinue to provide that level ofservices in that approach.This includesa forward forecast of capital needs fornew and renewed assets and for expen-diture on operations and maintenance.This ‘first pass’of the planning

process effectively establishes thebaseline of a life cycle strategy and theresourcing needs to deliver to it.The planning process is repeated

annually where the inputs andassumptions are reviewed andconfirmed. It is also during this‘pass’of the cycle that any existingor future potential gaps are identified –for example trends of product perfor-mance, asset reliability, conditions, etc.These are risk assessed for significanceand for those where a decision is madeto reduce or control the risk, theoptions are assessed and adjustmentmade to the resourcing needs.

Asset plansSydneyWater has two main typesof asset plans arising from thisplanning process.Area plans are SydneyWater’s

strategic servicing strategy for the city.The purpose of these plans is todetermine the most sustainable way of

servicing an area.Sustainabilityincludes economic criteria such aslowest lifecycle cost, but also reflectscommunity and stakeholder views onenvironmental and social values.Astrong emphasis of the area plan is tointegrate plans for the water,waste-water, recycled water and stormwatersystems, and (initially looked) tomaximise potential recycled waterprojects and other water conservationmeasures.The plans necessarily focus inon geographical areas (hence the namearea plans).The initial priority forpreparation of these was to focus in onlocations with greatest potentialrecycled water markets, such as areaswith high population growth or largeexisting water users.The output of thearea plans is a high level water cycleplan covering the sources of watersupply, the range of products andservices to be provided to customers(such as the extent and grade ofrecycled water provided) and anydischarges to the environment.The highest level of area plan

also looks at natural resourcemanagement (water balance,demand /supply balance, etc.) that is a majorconsideration in sustainable assetmanagement.This has been an area ofconsiderable focus for SydneyWater,but this paper does not describe orexplore that other key area.Asset management plans describe

the asset lifecycle strategy to managedifferent asset classes, such as pumpstations,pipes and treatment plants.The plans define the target levels ofservice and the optimum way to meetthese considering (life cycle) cost andrisk.The plans describe the way assetsin each asset class will be managedthrough their life cycle and includedecision frameworks for how decisionswill be made on aspects such as whento renew versus continue to maintain.The plans include an overarchingapproach to the renewal of assets usinga risk based methodology and assetcondition assessment.The plans defineshort- and long-term demands forcapital investment by driver, identifyconsequential changes to operatingcosts, and provide justificationfor renewals,maintenance andoperations expenditure.The asset planning approach

above applies to both forms of asset

Figure 1Asset planningprocess



developments,market forces, assetdeterioration and aging, etc.

Decision frameworksTo support the implementation of the(derived) asset life strategies, SydneyWater has also developed decisionframeworks.These were developedto streamline the management ofknown work such as major periodicmaintenance and asset renewal.Adecision framework clearly defineshow decisions on identifying assets forwork are to be made.These representthe thinking, the approach and the‘how’of certain asset managementdecisions (i.e. relevant factors and howthey will be considered and used).Forexample,how to decide when to stopmaintaining an asset and renew ordispose of it (at the end of its economicor service life);or, as another example,when to apply major periodicmaintenance to a type of asset(such as the relining of the interiorcoating of water reservoir tanks).In some decision frameworks, aspects

of sustainability have been moreexplicitly and transparently includedand reinforced.For example, theinclusion of social and communityimpacts in the asset life cycle decisionsfor the renewal of water mains.Or forexample, the strategy for leakage,which targets reduction to the pointwhere it makes sustainable businesssense (the economic level of leakagebased on the marginal cost of water).In the development and

management of these decisionmaking frameworks,SydneyWater’s approach and intent isfor the following to be achieved:• Safety and efficiency are keyconsiderations in the company’sasset management decisions

• An effective decision makingframework exists for each majorasset class

• The frameworks are flexible andadaptable over time

• They are successful in balancingeconomic, environmental andsocial outcomes

Document support toolsSydneyWater has also developed asustainability planning manual as aplanning support tool – this wasbuilt on earlier cooperative work ofmembers under the overview ofWSAA and underpins sustainabledecision making and planning.Thedecision making framework assists indealing with complex issues, sustain-ability requirements and licencecompliance for SydneyWater.Thisapproach integrates sustainability intodecision making frameworks, andincludes principles such as: a ‘project’should be ‘financially, environmentally,

technically and socially sustainable’.Stakeholders, community, etc.need tobe able to understand,participate inand accept decisions.The manual outlines a decision

making process and frameworkin six simple steps (phases) andprovides supporting guidelines,resources and tools.The six stepsare illustrated in Figure 2 andinclude definitions of objective,generation of creative options,selection of (sustainability) criteria,screening of options,detailed optionsassessment (with a multidisciplinaryteam and including engagement ofstakeholders) and recommendationof a preferred option by applying amulti-criteria approach, as a robust andtransparent method of ranking options.

Asset management frameworkAsset plans represent a snapshot in timeof the asset planning process.They arejust one element of a strategic assetmanagement framework in SydneyWater, that includes:• Policies – for asset management, assetcreation and maintenance

• Processes – plan, create,operate,maintain, renew,dispose

• Asset plans• Life cycle management strategies• Decision support tools• Risk management framework• (Quality) management system• Models and information systems• Competencies in asset management• Benchmarking, for continuousimprovement in asset managementprocesses

SydneyWater also prepares a State oftheAssets report annually.This providesa snapshot of aspects such as assetcondition and performance, and theoutcomes of previous investment, forexample,how that has changed riskprofiles. Importantly it also providesan assessment of the organisation’sasset management capability andof any improvement plans in placeor proposed to improve the assetmanagement capability. �

This paper was presented at the AustralianWater Association Sustainable Infrastructureand Asset Management Conference, 23-24November 2010, Sydney, Australia.

AcknowledgementThe preparation of the asset plansdrew on a range of expertise inasset planning,operations andmaintenance, and finance andeconomic skills inside SydneyWaterand from its planning partners.

ReferencesWSAA (2005) Evaluating the OverallSustainability of UrbanWater Systems.

plans. In effect, the plans representthe capture of the assumptions,processand the outcomes of two focusedforms of asset planning.SydneyWater carried out the initial

asset planning to prepare asset manage-ment plans in 2005 and has repeatedcycles since to update the asset plansfor each of its major categories orclasses of infrastructure assets:• Wastewater treatment plants• Water treatment plants• Sewage pumping stations• Water pumping stations• Reservoirs• Water pipes• Sewer pipes• Stormwater pipes

These plans are updated annually asa part of the business planning cycleand the outputs are aligned to thecycle.Area plans have been in placesince 2009.The asset plans are used as the

basis of the submission to thepricing regulator, i.e. they validate theprudency and robustness of investmentdecisions and expenditure allocations,and thus underpin the sustainability(of funding) for the organisation tocontinue to provide services.The outputs of the asset plans are

projections in three time horizons –quite precise and detailed in year oneestimates, a detailed forecast for fiveyears, and longer-term predictions andforecast for 30 plus years.The longer-term view is one key element tosustainable asset management.We havefound that scenario planning is a keytool for developing this longer-termview and that a range of scenarios needto be produced and assessed because ofthe uncertainty of inputs to theplanning process.The variability anduncertainty comes in the inputs suchas growth, customer values anddemands, climate change, technology

Figure 2Six phases of thedecision makingprocess andframework

Expected climate change effectssuch as increased rainfall /runoff, temperature rise, and risein seawater level will influence thewater infrastructure in Norway inseveral ways. If we consider theurban water system fromupstream water source to down-stream receiving water, climatechange in Norway will influencerunoff patterns to drinking watersources (i.e. lakes or rivers) andthereby affect raw water quality,longer drought periods willchallenge reservoir capacity andconsumption patterns, organiccompounds in water may lead toincreased biofilm growth andcorrosion in water pipes, andchanges in freeze / thawpatterns may cause morefrequent pipe bursts.On the wastewater side, increased

frequency of extreme runoff will be achallenge for the existing wastewaternetwork and operation of treatmentplants.More frequent CSO (combinedsewer overflow) outflow may disturbthe water quality of receiving bodies,and storm runoff combined with ahigher sea water level may affectdownstream sections of the wastewatersystem, for example by floodingCSOs and pumping stations andby submerging lower parts of thegravity network.Norway’s citieswill experience the effects of climatechange in different ways,dependingon the type of water sources usedand the catchment area,whetherthey are situated inland or on thecoast, and the current capacity oftheir water supply andwastewater systems.To avoid these potential problems,

several actions have to be taken that arebased on local circumstances, so acareful analysis of expected localimpacts of climate change is thereforenecessary.Based on these, legal actions

and regulation can constrain buildingon flood plains, and bring into placestricter requirements for treatmentplants, etc.Drinking water treatmentplants may need to be upgraded tocope with more organic substances inraw water, as well as emerging micropollutants.Weak parts of the drinkingwater network may need to be rehabil-itated to maintain system reliability, andcontrolling stormwater at source mayreduce extra hydraulic load on waste-water networks.Energy recovery fromwastewater flow and wastewatertreatment processes is also important inorder to obtain a carbon neutral urbanwater system.These potential actionsneed to be planned within a holisticscope,based on comprehensive riskanalysis.A national programme‘Cities of the Future’,hosted by theNorwegian Directorate for CivilPreparedness in conjunction with themain water utilities in Norway,hasbeen established in order to assistclimate change planning in the cities.

Recent events in NorwaySeveral recent events show thekind of problems that are expectedto increase in future.For example, a severe flood incident

occurred inTrondheim in 1997,whenheavy rain fell on frozen, snow-coveredground and caused an immediaterunoff response.Gullies connected tothe stormwater network were cloggedby ice,which increased the severity ofthe event (Milina 1999).Madsen(2007) similarly described andmodelled the impact of potentialflood events in the city of Bergen.Some events have been brought to

court to decide whether they are amunicipal responsibility or to be paidby insurance companies.As an exam-ple, one court defines the municipalresponsibility as ‘all rainfall events thatcan be imagined’,which has beeninterpreted as a return period of over

Adaptation of Norway’s water supply andsanitation systems to cope with climate changeClimate change can have impacts in all areas of the water industry, including quality

and availability of water sources and water and wastewater infrastructure robustness.

Today’s choices, particularly regarding investments in infrastructure, will significantly

influence the ability of the water industry to react to the climate change impacts of

tomorrow. In addition to the need to plan investments, new issues related to water

supply, health safety and environmental protection will also have to be accounted for. In

this article, Sveinung Sægrov and Rita Ugarelli highlight the need for evaluating the

relationship between expected climate changes in Norway and their impacts on urban

water components.


Sveinung SægrovProfessor, Norwegian University ofScience and Technology, Department ofhydraulic and environmental engineer-ing, Trondheim, Norway.Email: [email protected]

Rita UgarelliAdjunct Professor, Norwegian Universityof Science and Technology, Departmentof hydraulic and environmental engineer-ing, Trondheim, Norway.Email: [email protected]


Figure 1Changes inreservoir waterquality in Oslo(Eikebrokk et. al.2004)

ADAPTATION OF NORWAY’S WATER SUPPLY AND SANITATION SYSTEMS TO COPE WITH CLIMATE CHANGE

70 years.This is an enforced dutycompared to current internationalstandards (EN 752).In 2010 and 2011 Norway

experienced rather strong winters.This was shown to affect theweakest parts of the waterinfrastructure.The Norwegianmain cities experienced double thenumber of pipe bursts compared to anormal year,with damage mainlyoccurring on old cast iron pipes.

Long-term trends in water qualityNorway has experienced a doublingor even tripling of colour in waterreservoirs since 1970, as illustrated inFigure 1.The reason is not clear, butit is believed that it stems fromthe temperature increase that isdocumented over the last 40 years.As well as this, an increase of organic

matter in drinking water sources hasalso been measured in Norway andseveral other countries.This increase isexpected to continue due to increasederosion in catchments of the lakesserving the water supply.Such erosionmay happen as a result of more severerunoff situations. Increased contentof organic matter may also increasethe biological activity in water



Figure 2Impact of climatechange on rainfallintensity – south-western Norway.

Rainfall duration of60 minutes. (Holvik,

NTNU 2010)

urban water service systems in Norwayis estimated to cost €70 billion ($14billion),which is not affordable forNorwegian water utilities.Therefore,we will have to stick to the existinginfrastructure and make the necessaryimprovements to cope with climatechange, as well as ageing of pipelinesand plants, and increasing demand fromcustomers. Some actions have alreadybeen taken to adapt exiting systems tothe expected future needs.This alsoincludes participation in majorresearch activities within the EuropeanUnion framework programmes, such asTECHNEAU,PREPARED andTRUST,as well as other programmes.TECHNEAU was finished in 2010

and delivered technologies that helpcities handle climate change.Examplesare more robust and optimized watertreatment methods based on coagula-tion / filtration, and operationalcapacity of membrane systems fortreatment (Eikebrokk et al 2009,Azrague et al 2009). It also deliveredmethods to optimise maintenance ofwater distribution methods to avoidbacterial growth and sedimentation(Vreeburg 2010).These are methodsand techniques that have been broughtinto use in the forefront water utilitiesin Norway.PREPARED is a programme

focusing on the adaptation of existingwater infrastructure to the impact ofclimate change. It started in 2010 andwill run to 2013,with the aim ofmaking water and wastewater systemsmore robust and resilient.The pro-gramme includes the development ofmethods for risk assessment of theurban water cycle,methods for warn-ing and prediction of potential hazards,and suggestions of permanentimprovements that will increase the

capacity of systems for better perfor-mance during extreme events, such asincreasing dimensions of wastewaterconstructions.An overview of climatechange effects that may impact theurban water cycle has been developed(Ugarelli et al 2011).The Norwegiancapital of Oslo is heavily involved inthis project, and other Norwegiancities will use the programme’s findingsas input to their planning to meet theclimate change challenge.TRUST is a recently started

programme that deals with long-term sustainability, and will last until2014.One of the core issues is thedevelopment of a metabolism model(Figure 4) for urban water cyclesystems (Govindarajan 2011).This willbe instrumental to show how theentire system and its componentsperform currently, and how they willperform under different circumstances.A prominent feature of the model isthe ability to calculate use of resourcesand energy, the environmental impactof pollution in receiving waters, carbonemissions, and solid waste production.TheTRUST programme also encom-passes technologies for water andwastewater treatment, leakage control,rehabilitation of pipes, reuse of water,and energy minimization.Additionally,advice and software for the assessmentof sustainable solutions will be devel-oped. Norwegian cities are heavilyinvolved inTRUST.They will use theprogramme for implementing carbonfootprint calculations in their planningphilosophy (selection of materials,technical solutions, etc.)

Strategies of Norwegian citiesNorwegian cities have begun develop-ing strategies for sustainable develop-ment / production. In Oslo, forexample, the following main objectiveshave been set (Milina 2010):• Reduce greenhouse gas emissions• Reduce energy use• Increase resilience of city structuresand infrastructure

• Implement the new EUWater• Framework Directive• Plan for green-blue city growth

Long-term plans with a timehorizon of 10-15 years, as well asshort-term rehabilitation plans, arebeing developed, supported by anumber of tools for estimating futurerehabilitation needs, failure predictionand risk assessment.Computer-basedand geo-referenced informationsystems have existed for 25 yearsand are constantly being improved,which enable the cities to use advancedtools for condition assessment andcondition prediction.However, in spite of good plans and

large investments, a temporary increase

distribution networks,with biofilmformation as well as bacteria / virusesin biofilm already being observed indistribution systems.

Scenarios for future precipitationScenarios for precipitation in the year2100 have been developed by theNorwegian Climate adaptationprogramme and downscaled to urbanareas (Hansen-Bauer 2004,Holvik2010).As shown in Figure 2,which isof 60 minutes of rainfall for returnperiods of 2-100 years, a substantialincrease should be expected.Thecontrol periods are based on statisticsfor the period 1961-1990.TheA2scenario refers to societal development‘business as usual’ and B2 to a moreenvironmental development.It is obvious that increased

precipitation will influence theperformance of the wastewaternetworks.Calculations made forthe city of Sandnes showed a triplingof weir discharge volume (Holvik2010).Similar results have beenobtained for other cities in Norway(Madsen,2007).At the same time, the utilities will

also have to cope with sea level rise.The rise will vary from 0.5m to 1.0m,plus further increase driven by windpressure during storm events.Thedownstream part of wastewatersystems, including CSOs and pumpingstations,will be influenced by extremesea water level increases.Backflow maycause severe problems in downstreamgravity driven networks, in particular ifthe event also includes heavy runofffrom rainfall.Figure 3 shows an example from

Møllenberg inTrondheim (Holvik2009).The shaded area will be sub-merged during high tide in 2100.However, the flooded area influencingpipelines are much larger. In thiscatchment,30% of the network and15km of pipes will be submergedduring extreme sea water levels. It isobviously important to improve thisnetwork and reduce infiltration, as wellas protecting buildings from backflow.A particular issue in this area is the

location of CSOs,which will besubmerged during high tides. If themain wastewater system is to be kept,new types of weirs that can workduring submerged conditions need tobe developed.

Meeting the expected impactsA full rehabilitation of the existing

Figure 3City area ofMøllenberg,Trondheim, whichwill be flooded ifsea level rises(green shaded,Holvik, NTNU 2009).



of pollution in the city’s receivingwater bodies, such as Indre Oslo fjordand the city’s rivers,have beenobserved after major storm events.It is a concern that this will affectthe public trust in the municipalwater organisation and theirwillingness to pay for the necessarydevelopments.Technologicalcontributions to the improvementof the situation may include:• Regional optimisation (severalwastewater treatment plantsworking together,optimising thecapacity of transport systems,modelling and online monitoring)

• Utilising the storage capacity of theexisting network and new detentionsystem (Ormen Lange), investigatingpotential hygienic (due toovertopping)and technological consequences ofpressurizing the wastewater network

• Pollutant control in combinedstormwater systems

• Separation of storm and sewagesystems,source control and connectionto ‘green city development’

• Optimising wastewater treatmentplant capacity to deal with flow andquality variations

Structural improvements arebeing made, for example withregard to local control of stormwaterrunoff and storage of wastewater,such as green roofs installed forlocal stormwater control in Haraldrud,Oslo, and the planning of a newwastewater tunnel, also in Oslo.Anational guide for stormwaterhandling has been developed bythe NorwegianWaterAssociation(NorskVann;Lindholm et al 2005).Further,measures for adaptation toclimate change in the water andwastewater sector have been studied

in another recent report by theNorwegianWaterAssociation(Muthanna et al 2010).Nie et al2009 have also presented a reviewof research and development ofclimate change, risk managementof urban flooding, and adaptationto climate change.

ConclusionThe water utilities of the mainNorwegian cities will face substantialchallenges over the coming decadesdue to the impact of climate change, aswell as ageing of networks and treat-ment plants, and rapid populationgrowth. It is beyond financial capabili-ties to replace major parts of the urbanwater systems,but continuousimprovement of the existing systemwithin a long-term planning horizonand the development of new tech-niques, such as improved renovationsystems and planning methods, toolsfor financial planning, risk assessmentand environmental impact, is expectedto improve the cities’ ability to handlefuture challenges.�

AcknowledgementThanks to Oslo municipality,water andwastewater department, for valuableinformation and discussions.

This paper is based on a presentation givenat the IWA World Water Congress inMontreal, Canada, 19-24 September 2010.

ReferencesAzrague,K,Østerhus,SW and Leiknes,T(2009) Development and evaluation of a newconcept for water treatment: the OBM process. In:TECHNEAU:Safe drinking water from sourceto tap – state of the art and perspectives.Editors:Theo van den Hoven and Christian Kazner.IWA Publishing,London,UK. ISBN:

9781843392750.Eikebrokk,B,Vogt,RD and Liltved,H

(2004) NOM increase in North Europeansource waters, discussion of possible causes andimpacts on coagulation / contact filtrationprocesses.Water Science andTechnology:WaterSupply,Vol 4,No 4,pp 47-54.Eikebrokk,B (2009)Water treatment –

optimization with respect to what? In:TECH-NEAU: safe drinking water from source to tap –state of the art and perspectives.Editors:Theovan den Hoven and Christian Kazner. IWAPublishing,London,UK. ISBN:9781843392750.Giorgi,F,Bi,X and Pal, J (2004) Mean,

interannual variability and trends in a regionalclimate change experiment over Europe. II:climate change scenarios (2071-2100).ClimateDyn.23,pp 839-858,Springer.Govindarajan,V (2011)The ‘what’ and the

‘how’ of asset management in water treatmentplants.Paper developed for journal submission2011,Norwegian university of Science andtechnology.Holvik, IS (2009) Challenges for urban

water structures related to increase of sea waterlevel.Master study report,Norwegian Universityof Science and technology (in Norwegian).Holvik, IS (2010) Impact of storm water

runoff from climate change.Example study inSandnes,Norway.M.Sc. thesis at NorwegianUniversity of Science and technology.Madsen,AB (2007) Flood damages and

pollution effluents in Bergen.Analysis of climatechange effects.Master thesis,Department ofMathematical Sciences andTechnology,Norwegian University of Life Sciences (inNorwegian).Milina, J and Selseth, I (1999)Analysis of

flood conditions and calculation of return periodsfor flood events inTrondheim 1999.SINTEF-report:STF22A99310 (in Norwegian).Milina, J (2010) Personal correspondence.

Lindholm,O,Endresen,S,Thorolfsson,S,Sægrov,S and Jakobsen,G (2005) Guide tostorm water handling. In Norwegian:Veiledning iovervannshåndtering,Norsk vann (Norwegianwater) report no 144 (in Norwegian).Muthanna,T,Lindholm,O,Liltved,H and

Vogelsang,C (2010) Measures for adaptation toclimate change in the water and wastewater sector– pilot study Norsk vann report B14.Nie,L,Heileman,K,Hafskjold,LS and

Sægrov,S (2009) Review of research anddevelopment of climate change, risk managementof urban flooding and adaptation to climatechange,SINTEF report for Research Councilof Norway.Ugarelli,R,Leitão, J,Almeida,MC and

Bruaset,S (2011) Overview of climate changeeffects which may impact the urban water cycle.PREPARED,Deliverable number D2.2.1.Vreeburg, JHG,Menaia,L,Branco,M,

Benoliel,M,Aprisco,P,Rebola,N and Cordeiro,B (2009) Conceptual model for discoloration indrinking water systems.Who is to blame andwhat to do? In:TECHNEAU:Safe drinkingwater from source to tap – state of the art andperspectives.Editors:Theo van den Hoven andChristian Kazner. IWA Publishing,London,UK. ISBN:9781843392750.

Figure 4Resource flowmodel (metabolismmodel): material,energy and costsper consumptionunit for urbanwater services,environmentalimpact (carbonfootprint),Govindarajan,NTNU 2011


A THREE WATERS VISION FOR DUNEDIN, NEW ZEALAND

Aerial shot ofDunedin. Credit:Dunedin CityCouncil.

With the completion of anumber of substantial waterand wastewater infrastructureprojects in recent years, whichwere the result of strategic deci-sions made in the early 1990s, thetime has arrived when a newstrategic direction is required forthe City of Dunedin on NewZealand’s south island.The development of theThree

Waters Strategic Direction Statement(2010-2060) was seen as a necessarytool to address an obvious lack ofstrategic and sustainable planningcapability within the Council’s waterand waste services department.Thestatement outlines the principles,priorities and planning assumptionsthat will underpin decisions regardingwater, stormwater and wastewaterinfrastructure and service delivery inDunedin for the next 50 years.Together with their consultant

team,Dunedin City Council is con-tinuing to develop a long-termstrategy for the future management ofthe three waters (water,wastewater andstormwater).The strategy suggests anintegrated approach to dealing withthe decline in service performancethat would otherwise be evident in anetwork of ageing infrastructure and isalso expected to meet the new 21stcentury challenges of increasedcommunity expectations, a morestringent regulatory environment, andclimate change.Here is present a phased method of

determining the appropriate capitaland renewals response to ensure thatthe future investment in infrastructureis appropriate,optimised, sustainableand affordable,utilising a range ofmodelling tools and multi-criteriadecision-making techniques.Using a phased approach, starting

with the development of a strategicthree waters model,means that earlybenefits could be gained using existingknowledge complimented with anappropriate level of additional networkdata.The results of the first phase were

A three waters vision forDunedin, New ZealandThis paper presents an overview of how the Dunedin City Council (DCC) in New

Zealand has restructured its water and waste business unit, developed a Strategic

Direction Statement (2010-2060), and together with their consultant team, is

developing an integrated long-term strategy for the future management of the three

waters (water, wastewater and stormwater). By Dan Stevens, Tracey Willmott and

Laura McElhone.

Dan StevensOpus International Consultants,Christchurch, New Zealand

Tracey WillmottDunedin City Council, Dunedin, NewZealand

Laura McElhoneDunedin City Council, Dunedin, NewZealand


used to prioritise areas of further studyin subsequent phases,which involvedmore detailed investigations.With the project nearing comple-

tion, the paper will describe theapproach taken by the team to confirmlevels of service, to build and calibratehydraulic models and develop tenintegrated catchment managementplans for the city based on a frameworkdeveloped during an initial pilot study.The final stages of the project will

include the preparation of master plansoutlining a programme to addresssystem deficiencies across the threewaters for each of the future planningscenarios and will identify prioritisedoperational improvements and capitalworks using an integrated decision-making approach.The project will answer many of the

strategic questions posed in theStrategic Directions Statement (2010-2060) and provide guidance for furtherinvestigation where the questionscannot be answered directly by theThreeWaters Strategy Study.

A business improvement strategyIn order to drive the necessary invest-

ment programme,Dunedin CityCouncil (DCC) has developed anintegrated asset management approachand has embarked on a businessimprovement project in order meet itscapital and operational delivery targets.The process has two main compo-

nents.The first being to restructure thewater and waste services business unit,and the second being to undertake asignificantThreeWaters Strategy Studythat includes the development ofhydraulic models to examine the entirewater cycle within Dunedin’s urbancatchments, and to provide criticalinformation on the performance ofthe networks.

A restructure of the business unitRunning in parallel with Phase 1 of thestrategy study, the removal of thepreviously prominent operational ‘silo’based structure and introduction of anintegrated ‘ThreeWaters’ strategicstructure was seen as key to the futuresuccess of the business unit.The nature and requirements of

the strategy study, and indeed thedevelopment of theThreeWatersStrategic Directions Statement (2010-



2060),would serve to reinforce thisnew approach and there is no doubtthat this has helped to reshape theoperating philosophy of the water andwaste services business unit.This hasperhaps been the most significantbenefit of the project outside of the keyproject deliverables.Integration and streamlining of

business systems and processes hasbeen a key objective of the restructure.There has been a real focus ondeveloping integrated systems,ensuring consistency in data handlingand adopting a common approachacross the three waters.

A collaborative approachPromoting a collaborative andinclusive approach was identifiedas key to ensuring the success of theThreeWaters Strategy project.Giventhat tenders were received from sixstrong consortia, this proved to be aprincipal criteria used for selectingthe consultant team to work withDCC on the project.In December 2007 DCC appointed

a consultant team lead by OpusInternational Consultants to undertakethe project.The consultant teamcomprised Opus and URS NewZealand, and sub-consultants would beappointed throughout the project toundertake specialist tasks such as flowmonitoring and stream assessments.Additionally,Metrowater (a councilcontrolled organisation fromAuckland)were appointed as ‘industry advisors’ tothe project and Beca were appointed as‘project reviewers’.As the water and waste business unit

was being reorganised during Phase 1,a number of new and often inexperi-enced staff were joining the DCC teamas the project progressed. It was essen-tial that these new team members wereable to draw upon and learn from theknowledge and experience of thecombined project team,and a collabo-rative approach and willingness to shareknowledge and advice was essential.

Guiding the projectA Project Control Group (PCG) wasformed that would provide guidanceand strategic direction throughout theproject.The PCG would meet monthlyand comprised key members of theDCC water and waste services businessunit, together with representatives fromthe consultant team, the industryadvisors and the project reviewers.Open discussion and a shared desire toachieve a successful outcome for theproject have proved to be the hallmarksof the PCG.

Developing the strategicdirection statementThe development of aThreeWaters

Strategic Direction Statement (2010-2060) was a key stage in the process asit effectively defined ‘the vision’ for thethree waters for Dunedin up to 2060.The statement outlines the principles,priorities and planning assumptionsthat will underpin decisions regardingwater, stormwater and wastewaterinfrastructure and service delivery inDunedin for the next 50 years.A process of inclusive community

and stakeholder consultations providedvaluable guidance in terms of settingmeaningful goals, defining appropriateand affordable levels of service stan-dards and clarifying the community’swillingness to pay to meet these targets.

Project driversA number of key project drivers wereidentified for theThreeWaters StrategyStudy,which included:• Reviewing and setting appropriatelevels of service

• Developing an optimised investmentplan for network renewals

• Building multiple redundancy intothe networks where appropriate

• Optimising the operation of thethree networks

• Investigating alternative watersources and demand management aswater conservation tool

• Investigations of future waterstorage options

• Sustainable solutions andintergenerational equity

• Integrated catchmentmanagement planning

• Protect the environment and preventsewer flooding incidents

• Answer strategic questions posed intheThreeWaters Strategic DirectionStatement (2010-2060)

A three phased approachIt was decided to adopt a three phasedapproach to the study.• Phase 1 – Developing strategiclevel water and wastewater models,capital works master plans atstrategic level, and a pilot catchmentmanagement plan

• Phase 2 – Detailed investigations,capital works master plansextended to reticulation level,complete remaining catchmentmanagement plans.

• Phase 3 – Construct projects andcontinued iteration and refinementof phases 1 & 2, improvement inaccuracy of expenditure profiles

Using a phased approach, starting withthe development of strategic levelmodels,meant that early benefits couldbe gained using existing knowledgecomplimented with an appropriatelevel of additional network data –effectively quick wins that wouldprovide confidence in the project and

the investment by council.The results of the first phase would

prioritise areas of further study insubsequent phases,which involvedmore detailed investigations.

What is an integrated solution?In the originalThreeWatersVisionstatement it was established that thestrategic objectives of the business unitcould only be met by understandingthe entire water cycle within the cityenvironment,which would require anintegrated approach to catchmentmanagement and infrastructureplanning, as each of the three waterstates has an influence on the other insome way.However, at the start of the

DunedinThreeWaters Strategy Studyit is fair to say that neither DCC northe consultant team had a clearunderstanding of what ‘integration’meant in practice,with respect to theproject and for the wider operation ofthe newly restructured DCCWaterandWaste Services team.A key out-come for the DunedinThreeWatersStrategy Study as a whole is to developoptimised and integrated solutionsacross theThreeWaters as far as ispractical – but what does this meanand what is practical?A series ofworkshops were held which resultedin a clearer understanding of thepotential for the project to deliverintegration across a number of areas.These were summarised under anumber of sub-headings, including:• Common business systems• Growth and planning• Modelling• Innovative solutions• Understanding interactions• Common three waters issues

Significant progress has been made inmany of these areas within a shortspace of time, through the businessimprovement process and as theThreeWaters Strategy Project has progressed.Whilst the processes of integration inthe context of the project are nowbetter understood, the potential for amore integrated set of capital invest-ment decisions would only really bepossible during the later stages of theproject.For example, as the teamgained a better understanding ofsystem demand,growth potential andthe predicted effects of climate changeon the principal water sources, theneed for significant demand manage-ment, grey water reuse or stormwaterharvesting were demonstrated asunnecessary and uneconomic.

Setting appropriate levels of serviceOne of the first defined objectivesof the project was reviewing theagreed community outcomes, setting



appropriate levels of service anddetailing key performance indicators.The community outcomes wereessentially defined by consultationsand development of the LongTermCouncil Community Plan (LTCCP)and levels of service targets are to acertain extent driven by these agreedcommunity outcomes,DCC’s strate-gic objectives and the community’swillingness and ability to pay.A widerange of activity management plansfrom other New Zealand territorialauthorities were reviewed to deter-mine typical levels of service adoptedacross the country.New Zealand andAustralian benchmarking data was alsoreviewed,enabling DCC to set a targetlevel for performance that would beboth appropriate and affordable for theCity of Dunedin.In developing the capital works

investment programme, the sensitivityto levels of service targets was investi-gated using the hydraulic models,enabling more informed decisionmaking and providing surety ininvestment decisions and equity forthe current and future generations.

Prioritisation and optimiseddecision makingA key part of the Phase 1 workswas to develop an integrateddecision making (IDM) process.This would allow issues to be rankedagainst a risk based framework and forresulting projects to be scored basedon their benefit related to the agreedcommunity outcomes and prioritisedacross the three waters. Indeed, if thisprocess proved successful it was likelythat this could form the basis forproject prioritisation across thecouncil as a whole.‘Issues’were identified in a

number of ways.Firstly,detaileddiscussions were held with thesystem operators,who wereencouraged to share their knowledgeand experience gained from runningthe systems over many years. Secondly,system performance informationwas collated and analysed.Thisinformation included records ofcustomer complaints for low or highpressure or poor water quality,bursts,sewer blockages, sewer / stormwateroverflows, etc.These were geocodedand entered into the GIS system andimported into the hydraulic modelsfor more detailed analysis. Systemdeficiencies were identified throughanalysis of the hydraulic models undercurrent and future demand conditions.Once the issues had been identified

the question was posed ‘does this causea problem (related to one or morelevels of service criteria)?’. If noapparent problem was evident theissue was recorded in the system

performance report and no immediateaction was taken. If a problem wasidentified the issue went forward for arisk analysis.The risk was assessed against an

agreed scoring methodology and theproblem was classified as ‘manageactively’or ‘manage passively’.Forthose classified as ‘manage actively’ arange of potential solutions weredeveloped and discussed at workshopsheld with DCC operations and plan-ning staff.Each option was scored interms of their effectiveness to solve theproblem and on their benefit related tothe agreed community outcomes andthe quadruple bottom line of the ‘fourwellbeings’ (cultural, environmental,social and economic).Finally,budget costings were devel-

oped for the favoured solutions,whichcould then be ranked across the threewaters and a prioritised staged capitalinvestment programme established.This staged capital plan would formthe cornerstone for the future activitymanagement plan (AMP).For the firsttime it will be possible for the waterand waste business unit to create asingle integratedAMP covering thethree waters.This prioritisation across the three

waters marked a fundamental shiftaway from the previous policy wherebyeach of the waters was allocated aseparate ‘pot’of money. In the future,budget prioritisation can occur at anamalgamated level.

Integrated modellingOne of the most interesting aspectsof the project to date has been theintegrated approach to the hydraulicmodelling.At the commencementof the project a review of theavailable hydraulic modellingpackages was undertaken.Key to the selection would be the

ability of the modelling software tomodel water,wastewater and stormwa-ter.An added complication was thatmodelling the raw water system wasalso added to the project, and thiscomprised a mixed pressurised andnon-pressurised system.It was also agreed that since a vast

amount of system information was tobe collated an asset management toolwould be advantageous.TheInfoWorks modelling platform wasselected as the most suitable commonmodelling platform for the project, andthis was complimented by the InfoNetasset management system.A single integrated,user-friendly

common modelling platformwould also provide the best long-term solution for DCC as well asfor theThreeWaters Strategy project,since it was planned to have a smallbut flexible permanent modelling

team as part of the water and wasteservices business unit.Great care was taken to design the

database architecture within theInfoWorksWS and CS models toensure a co-ordinated approachwas taken from the start.Goodexamples of this were developinga common node / asset namingcon

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