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Chapter 4 Sustainability Assessment For Urban Water Management System 98 CHAPTER: 4 SUSTAINABILITY ASSESSMENT FOR URBAN WATER MANAGEMENT SYSTEM 4.1 INTRODUCTION Sustainability assessment is the first logical step before any sustainability-enhancement planning. In short it is a type of approach like “does boiling water really need additional heating?” Sustainability assessment means each case should undergo a preliminary analysis to know its sustainability status before embarking on to more complex levels of data- gathering, analysis and problem-solving stages for any planning practice. Urban Municipalities are facing numerous challenges in respect of the provision and management of water services. Various benchmarking initiative measures the performance of authorities with respect to national standards and regulatory frameworks pertaining to the delivery and quality of water services. These may become useful tool for municipality for development of best practices and to determining potential for water services to be sustainable in the long run for future perspective. Sustainability assessment is the process to consider and measure the well being of people and the ecosystem together with the collected data. It can be used to ranking fields of activity, giving improvement suggestion for technology adoption, identifying the appropriate solutions for the proposed planning design. (Li Shuping et al, 2006) Integrated sustainability assessment is part of a new paradigm for urban water decision making. Multi criteria decision aid (MCDA) is an integrative framework used in urban water sustainability assessment, which has a particular focus on utilizing stakeholder‟s participation (E.Lai et al, 2008). The United Nations Environment Program (UNEP) s (Millennium Ecosystem Assessment, 2003) program has stressed the importance of better decision- making for long term sustainability and the importance of utilizing sound scientific knowledge Viz. Better information cannot guarantee improved decisions but it is a prerequisite for sound decision making”. Decision making thus requires sound sustainability assessment to provide key and timely information. In this research work, for sustainability assessment methodology adopted is described further in detail.

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Chapter 4 Sustainability Assessment For Urban Water Management System 98

CHAPTER: 4

SUSTAINABILITY ASSESSMENT FOR URBAN WATER

MANAGEMENT SYSTEM

4.1 INTRODUCTION

Sustainability assessment is the first logical step before any sustainability-enhancement

planning. In short it is a type of approach like “does boiling water really need additional

heating?” Sustainability assessment means each case should undergo a preliminary analysis

to know its sustainability status before embarking on to more complex levels of data-

gathering, analysis and problem-solving stages for any planning practice.

Urban Municipalities are facing numerous challenges in respect of the provision and

management of water services. Various benchmarking initiative measures the performance of

authorities with respect to national standards and regulatory frameworks pertaining to the

delivery and quality of water services. These may become useful tool for municipality for

development of best practices and to determining potential for water services to be

sustainable in the long run for future perspective. Sustainability assessment is the process to

consider and measure the well being of people and the ecosystem together with the collected

data. It can be used to ranking fields of activity, giving improvement suggestion for

technology adoption, identifying the appropriate solutions for the proposed planning design.

(Li Shuping et al, 2006)

Integrated sustainability assessment is part of a new paradigm for urban water decision

making. Multi criteria decision aid (MCDA) is an integrative framework used in urban water

sustainability assessment, which has a particular focus on utilizing stakeholder‟s participation

(E.Lai et al, 2008). The United Nations Environment Program (UNEP) s (Millennium

Ecosystem Assessment, 2003) program has stressed the importance of better decision-

making for long term sustainability and the importance of utilizing sound scientific

knowledge Viz. Better information cannot guarantee improved decisions but it is a

prerequisite for sound decision making”. Decision making thus requires sound sustainability

assessment to provide key and timely information.

In this research work, for sustainability assessment methodology adopted is described further

in detail.

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Chapter 4 Sustainability Assessment For Urban Water Management System 99

4.2 METHODOLOGY

Chart 4.1 Flow chart describing methodology for sustainability assessment

4.2.1 DEVELOPMENT OF SYSTEM BOUNDARY:

The system boundaries must be defined to include whole system rather than system

components. Moreover, the sustainability indicators (SI) must reflect all dimensions of

sustainability including all functional, economic, environmental and social- cultural aspects

(Balkema et al, 2002). The system boundary is defined as building a theoretical framework,

which provides the underlying basis for indicator selection and supported the overall index

structure. The four-dimensional view on sustainability was employed and these four

dimensions constituted the basic components of the sustainability assessment.

In other words, for sustainability assessment of urban water management system which

component of water system should be included? In this research, I have tried to incorporate

Aggregate weight of criteria and sub criteria

Composite index value (SI)

Decide system boundary

Decide criteria and sub criteria

Prepare questionnaire for interview of experts, stake holders

Ranking of criteria and sub criteria

Decide weightage of each criteria and sub criteria

Normalization of data

Data collection

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Chapter 4 Sustainability Assessment For Urban Water Management System 100

different component related to water supply, waste water, storm water, rain water

recharging/harvesting and its sub criteria. The system boundary is decided based on

following approach.

Fig 4.1 System boundary for sustainability assessment

Literature review

By considering local issues related to water management

By considering component of life cycle of water supply

Waste water treatment Sludge treatment Land fill

Energy recovery

Rain water Rain water recharging /

Harvesting

Raw water

Water treatment

Distribution

Use

Waste water

generation

Energy

consumption

Storm water

collection

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Chapter 4 Sustainability Assessment For Urban Water Management System 101

The literature related to sustainability assessment were studied and explained in previous chapter.

The local issues related to water supply as well as waste water management system were studied

and explained in chapter 1 (problem definition). The life cycle boundaries define the unit processes

to be included in the system. The life cycle for the urban water system starts with withdrawal of raw

water form source. It also includes components related to water and wastewater treatment. The life

cycle ends with discharge of treated sewage and disposal of sewage sludge either to land fill or

agricultural land. The system boundary covers storm water piped network and rain water

recharging/harvesting system coverage in the city. It also covers salinity ingress in Surat city. The

ground water is very important criteria but the data related to ground water table were not available

hence it was decided to skip otherwise it may result into false analysis.

4.2.2 SELECTION OF CRITERIA & SUB CRITERIA:

The system boundary was decided for the development of sustainability criteria and sub

criteria. This system model was adapted from the Triple bottom line approach used by

(christen et al, 2006). The criteria and sub criteria were decided based on prolonged time

perspectives to achieve more sustainable UWM system. The criteria selection (termed „data

selection‟) involved the selection of appropriate criteria for the field of research. It gives their

relevance to current issues, their appropriateness to the area in question, their scientific and

analytical basis plus their ability to effectively represent the issues designed for measurement.

The selected criteria represents following objectives to achieve sustainable water

management. This stage involves specifying a comprehensive set of objectives that reflects

all concerns relevant to the decision problem and measures for achieving those objectives

which are defined to achieve. Sub criteria measuring the same or similar aspects were either

excluded or replaced with more suitable indicator measures. Following guidelines were given

by (C Mureverwi et al, 2007) which is followed before deciding criteria and sub criteria.

Availability of data: The indicator should use good quality, affordable and readily available

data.

Simplicity: The information gathered for the indicator must be presented in an easily

understandable and appealing way. Complex issues and calculations should yield clearly

presentable and understandable information.

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Chapter 4 Sustainability Assessment For Urban Water Management System 102

Policy relevance: The indicator should be associated with one or several issues around which

key policies are formulated. This is because sustainability indicators are intended for

audiences to improve the outcome of decision-making on levels ranging from individuals to

the entire biosphere. Unless the indicator can be linked to critical decisions and policies, it is

unlikely to motivate action.

Validity: The data used in the index should be collected using scientifically defensible

measurement techniques. Methodological rigor is needed to make the data credible for both

experts and the general public.

Time-series data: The indicator should use data which reflect trends over time.

Reliability: The same information should be provided by multiple applications of an

indicator using the same data. Ideally two different researchers should arrive at the same

conclusions using the same indicator.

The following table 4.1 represents main criteria chosen and its objectives for sustainability

assessment of the study area. The detail significance of measurement of each sub criteria are

mentioned in table 4.2 on next page.

Criteria Objective

Social social fairness and equitable resource distribution

Economic economically sound principles, economic growth and cost returns

Environmental use of renewable energy source, environmental protection and

preservation of ecological systems

Engineering sensitivity and robustness in the system

Table 4.1 Objective of different criteria for sustainability assessment

4.2.3 DATA COLLECTION

In the research work, data were collected based on decided criteria and sub criteria. This

includes data related to social, economic, environmental and engineering factors and its sub

criteria like population served by water supply and waste water system, storm water, capital

investment, economic expenditure and maintenance, water supply per capita per day, waste

water generation per capita per day, area covered under pipe network, energy consumption,

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Chapter 4 Sustainability Assessment For Urban Water Management System 103

Criteria Sub criteria Significance of measurement

Social Access to water supply % population covered under water supply

Access to sanitation % population covered under water supply

Water

availability/capita/day

Per capita water supplied on daily basis

Supply hours Water supply hours on daily basis at

consumer tap

Service complaints Complaints related to water supply

Flood prone area Area which become water logged during

rain fall

Capital investment

Total initial investment towards water

supply infrastructure

Economic Cost recovery & Operation

and maintenance cost

Routine daily expenditure for water supply

and maintenance cost

Research and development

investment

Fund kept aside for research and

development

Water withdrawal

Quantity of water withdrawn from raw water

source on daily basis

Waste water treatment

performance

Verification for treatment and disposal

standard of waste water

Pollution load on

environment

How much pollution can be generated due to

disposal

Water reuse Treated waste water is being used or not

Recycling of nutrients and

sludge reuse

Nutrient and sludge is being used or not

Environmental Storm water-area covered

under pipe network

% area covered with piped network

Rain water

harvesting/recharging

% area covered with rain water

recharging/harvesting system

Salinity ingress Area in which ground water become saline

Engineering Metered connection Area cover under metered connection

Service interruption &

Water losses

Water loss in piped network and water

supply infrastructure

Table 4.2 significance of different criteria measurement for sustainability assessment

cost recovery, revenue collection from water supply, sewerage system, flood prone area etc.

from Surat municipal corporation (SMC).

In the first phase, for sustainability assessment most of the data were easily available from

Surat municipal offices and www.suratmunicipal.org website. One of the important data

(depletion of ground water table) was not available. How to address the issue when data were

missing is very challenging job. The non-availability of data is one of the largest constraints

to the success of most assessment study; the instance with incomplete data either substitution

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Chapter 4 Sustainability Assessment For Urban Water Management System 104

or exclusion of that data were adopted hence sub criteria depletion of ground water table was

omitted in this research work.

4.2.4. FIELD SURVEY

The questionnaire was prepared based on criteria and sub criteria which are essential for

sustainable urban water management. The survey was conducted among different category of

people to get representative results. The people involved in survey were local residents of the

Surat city, experts in the field of water management and stake holders.

The field survey consists of filling of two types of questionnaire:

Ranking sheet

Rating sheet

The ranking sheet defines the priority of different factors in comparison with rest of the

factors. The criterion weight can be defined as a value assigned to an evaluation criterion

which indicates its importance relative to other criteria under consideration. Assigning

weights of importance to evaluation criteria accounts for

1. The changes in the range of variation for each evaluation criterion, and

2. The different degrees of importance being attached to these ranges of variation.

For local residents of the city only ranking sheet was used as they can easily understand the

criteria and rank them as per their priority of importance. The weightage assignment is very

important and prime survey in the field study. The weight assigned by the experts on different

aspect of water management based on priority was the major input gathered through survey

and discussion with experts. Their vast experience and expertise increased value added

opinions in the priority-based field study. The co-operation was fully devoted by the experts.

Some have asked for soft copies of survey sheet in that case soft copy were sent them so time

for the second visit was saved. The survey mainly comprised of forty personal interviews

with local public, experts and stakeholders. The questionnaire format is shown below. The

summaries of questionnaire sheet (ranking and rating) are attached in annexure. The

questionnaire is enclosed as appendix I. The ranking sheet and rating sheet along with final

weightage is attached as appendix II and III respectively.

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Chapter 4 Sustainability Assessment For Urban Water Management System 105

4.2.5. ANALYSIS METHOD:

In recent years, quantitative multi criteria methods have been widely used for comparative

evaluation of complicated technological and social-economic processes as well as for

determining the best alternative among the available options and ranking the alternatives

based on their significance for a particular purpose. Professor of Vilnius Gediminas

Technical University E.K. Zavadskas was the first to use these methods in Lithuania in the

mid eighties of the last century for evaluation, substantiation and choosing of optimal

technological solutions at various stages of construction. In this period, new multi-criteria

evaluation methods were developed and widely used in the world in various scientific and

practical areas. Later, numerous disciples and colleagues of Prof. Zavadskas as well

representatives of various scientific schools extensively used the considered methods in

Lithuania.

The main concept behind the quantitative evaluation methods is integration of the values of

the criteria describing a particular process and their weights (significances) into a single

magnitude i.e. the criterion of the method. For some particular (maximizing) criteria, the

largest value is the best while for others (minimizing criteria) the smallest value is the best.

The units of criteria measurement are also different. The alternatives compared are ranked

according to the calculated values of the criterion of the method. Great numbers of multi-

criteria evaluation methods based on different logical principles and having different

complexity levels and the inherent features have been created in the world. There is hardly

any „best‟ multi-criteria evaluation method. Therefore, a parallel use of several multi-criteria

evaluation methods as well as the analysis of the spread of estimates and averaging of the

values obtained may be recommended for evaluating complicated multifaceted objects and

processes ( Valentinas Podvezko et al, 2011). A simple form of MAUT or simple multi-

attribute rating technique (SMART) which uses simple additive weighting method as the

utility function (Mingshen Wang, 1998) is used in his research.

The method SAW (Simple Additive Weighting) is one of the simplest, natural and most

widely used multi-criteria evaluation methods. It clearly demonstrates the idea of integrating

the values and weights of criteria into a single estimating value – the index of the method. In

this work, the Simple additive weightage method is used and following steps were adopted

for index calculation;

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Chapter 4 Sustainability Assessment For Urban Water Management System 106

A ranking approach was adopted, in which criteria and sub-criteria were ranked

within their category.

In second step, expert weights were assigned to all criteria and sub criteria for rating.

The criteria chosen were both qualitative and quantitative over widely differing on

ranges. The data were normalized. The normalization involved the conversion of

these criteria and sub criteria to a comparable form which ensures commensurability

of data. The criteria were compared with target value (service level benchmark) based

on their unit of measurement.

The scores were normalized (converted) by the following formulas

Xij= 𝒂𝒊𝒋

𝒂𝒋𝒎𝒂𝒙

---------------- (1)

Xij=𝒂𝒋 𝒎𝒊𝒏

𝒂𝒊𝒋

---------------- (2)

Where, aij = actual existing data value for the sub-criteria

ajmax, ajmin = target data value for sub-criteria

When criteria were maximized, formula (1) is to be used, and formula (2) is to be used when

criteria were minimized. For normalization threshold value/service level benchmark is taken

as a standard value.

The Weighting entailed the aggregation of criteria and sub-criteria.The aggregation

refers to grouping of criteria and sub-criteria. A composite index approach was

employed to calculate the overall sustainability index score. The normalized value for

each criterion Xij, was multiplied by the aggregate weight of criteria and sub-criteria.

The score for each sub-criterion were added to get final Sustainability Index value.

SI= max 𝑿𝒊𝒋𝒘𝒊𝙭𝒋 𝒋 = 𝟏,…𝒏𝒎𝒊=𝟏

Where, SI = total score

𝙭𝒋 = Weight of number of sub criteria

𝒘𝒊 = weight of the criterion and

𝑿𝒊𝒋 = normalized score for the criterion.

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Chapter 4 Sustainability Assessment For Urban Water Management System 107

4.2.6 SAMPLE CALCULATION FOR SUSTAINABILITY INDEX

Sample calculation for sub criteria access to water supply is shown below:

Step: 1 Composite Weight = weight of sub criteria × weight of criteria

= 0.2 × 0.24

= 0.048

Step: 2 Normalized value = Actual data/ Service level benchmark data

= 56/100

= 0.56

Step: 3 Final value = normalized value × average of expert weight

= 0.56 × 0.2

= 0.112

Step: 4 Addition of final values of all social criteria results into social index.

4.2.6.1 SOCIAL CRITERIA

Criteria

Average

weight of

expert view

Composite

Weight

Actual

data

Service

level

benchmark

Normalised

value Final value

Access to

water supply 0.2 0.048

56%

100%

0.56 0.112

Access to

sanitation 0.15 0.036

26.73%

100%

0.2673 0.040

Service

complaint 0.14 0.0336

417

no/year

NIL

2.3 X10⁻3 3.22 X10⁻4

Flood prone

area 0.13 0.0312

239 no

/year

NIL

4.18 X10⁻3 5.43X10⁻4

Supply hours

daily 0.17 0.0408

3

hours/day

24

hours/day

0.125 0.021

Water

availability 0.21 0.0504

180

LPCD

135 LPCD

1.33 0.279

Table 4.3 Weightage of sub criteria and index value of social criteria

The above table 4.3 and chart 4.2 represents water availability to the consumer is very good

comparing to access to water supply in terms of percentage population.

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Chapter 4 Sustainability Assessment For Urban Water Management System 108

Chart 4.2 Graphical presentations of Social Index value

4.2.6.2 ECONOMIC CRITERIA

Criteria Average Weight Actual

Data

Standard Data Normalised

Value

Final

Capital

Investment

0.29 0.0696 56.00 % 100 % Population

should Get Good

Quality Water

0.56 0.1624

Operation

and Maintain

0.5 0.12 58.88

Crore

(2008-

09)

100 % Capital

Investment should

be recovered

(59.27 crore)

0.9935 0.49675

Research and

Development

Investment

0.21 0.0528 0 20 % 0 0

Total 0.65915

Table 4.4 Weightage of sub criteria and index value of Economic criteria

00.05

0.10.15

0.20.25

0.3

ACCESS TO WATER SUPPLY

ACCESS TO SANITATION

SERVICE COMPLAINTS

FLOOD RISK

SUPPLY HOURS DAILY

WATER AVAILABILITY

SOCIAL CRITERIA

INDEX VALUES

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Chapter 4 Sustainability Assessment For Urban Water Management System 109

Chart 4.3 Graphical presentations of Economic Index value

4.2.6.3 ENVIRONMENTAL CRITERIA

Criteria Average Compo

site

Weight

Actual

Data

Standard Data Normalised

Value

Final

Water Withdrawal 0.14 0.0392 692 MLD 700 MLD 1.011 0.141

Energy Consumption 0.11 0.0308 73464058

(KWH)

Max. Energy

should be used

from Renewable

Sources

1.36 X 10-8

1.496 x

10-9

Amount of waste water

treated

0.12 0.0336 94 % 100 % of the

waste water

generated

0.94 0.1128

Waste Water Treatment

Performance

0.11 0.308 Acc. Std.

Data

WHO Standard

100 %

1 0.11

Water Reuse 0.12 0.0336 0% 100 % 0 0

Recycling of Nutrients

and Sludge Reuse

0.1 0.028 0% 100 % 0 0

Storm Water Area

covered under pipe

network

0.1 0.028 45.22 % 100 % 0.4522 0.4522

Rain Water Harvesting

Recharging

0.1 0.028 0.50 % 100% 0.005 0.005

Salination Ingress 0.1 0.028 3.88 % Should be

minimum

0.2577 0.2577

Total 0.4351

Table 4.5 Weightage of sub criteria and index value of Environmental criteria

00.10.20.30.40.5

CAPITAL INVESTMENT

OPERATION AND MAINTAINENCE

RESEARCH & DEVELOPMENT INVESTMENT

ECONOMIC CRITERIA

INDEX VALUES

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Chapter 4 Sustainability Assessment For Urban Water Management System 110

Chart 4.4 Graphical Presentations for Environmental Index Value

The table 4.4 and chart 3.4 reveals operation and maintenance cost fully recovered whereas

research and development fund is nil that need to be improved.

The table 4.5 and chart 3.5 shows more sustainable water supply system can be develop by

employing water reusing/ nutrient recycling/rain water recharging facilities and by

developing usage of renewable energy sources.

4.2.6.4 ENGINEERING CRITERIA

Criteria Average Weight Actual

Data

Standard

Data

Normalised

Value

Final

Metered

connection 0.4 0.0864 0.41% 100% 0.0041 0.00164

Service

interruption and

water losses

0.6 0.1536 20% MINIMUM 0.05 0.03

Total 0.03164

Table 4.6 Weightage of sub criteria and index value of Engineering criteria

00.020.040.060.08

0.10.120.140.16

WATER …

ENERGY …

AMOUNT OF …

WASTE WATER …

WATER REUSERECYCLING OF …

STORM WATER -…

RAIN WATER …

SALINATION INGRESS

ENVIRONMENTAL CRITERIA

INDEX VALUES

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Chapter 4 Sustainability Assessment For Urban Water Management System 111

Chart 4.5 Graphical presentations for Engineering Index value

The above table 4.6 and chart 4.5 represents both engineering sub criteria need to be

improved. It is found that engineering criteria has more potential to develop sustainable

system by making whole water supply network metered and by accurately measuring water

losses or conducting water audit.

4.2.6.5 COMPOSITE AGGREGATE INDEX

Main Criteria Final index value

for individual

criteria

Weight of

main

criteria

SI value for UWM

Social criteria 0.453 0.24 0.1087

Economic criteria 0.65915 0.24 0.158196

Environment criteria 0.435 0.28 0.1218

Engineering criteria 0.03164 0.24 0.0075936

Sustainability Index 0.396289

Table 4.7 Composite aggregate Index value for all criteria

The table 4.7 and chart 4.6 represents Social, Economic, Environmental, Engineering Indexes

are 0.453, 0.659, 0.435, 0.03164 respectively. The composite sustainability index for water

management system of Surat city is 0.396289. The major reason found is poor performance

of engineering criteria. The individual index also reflects engineering criteria is having very

00.005

0.010.015

0.020.025

0.03

METERED CONNECTION

SERVICE INTERRUPTION AND

WATER LOSSES

ENGINEERING CRITERIA

INDEX VALUES

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Chapter 4 Sustainability Assessment For Urban Water Management System 112

low index value 0.03164. Hence, it is concluded that by improving the system for engineering

criteria composite aggregate index can also be increased. Based on this preliminary

sustainability assessment in the next phase work is carried out to improve engineering

criteria. Therefore, further research has been done on reduction of water losses from the

system.

Chart 4.6 Graphical presentation of composite aggregate Index

0

0.05

0.1

0.15

0.2SOCIAL CRITERIA

ECONOMIC CRITERIA

ENVIRONMENT CRITERIA

ENGINEERING CRITERIA

MAIN CRITERIA

INDEX VALUES