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RESEARCH ARTICLE

Water’s Role in Smart Cities

Teresa Zawerthal da Silveiraa, Helena M. Ramosb

aMaster student of Civil Engineering at Instituto Superior Técnico, Technical University of Lisbon, Lisbon, Portugal; bPhd. Professor in Civil

Engineering Department and CEHIDRO, Instituto Superior Técnico, Technical University of Lisbon, Lisbon, Portugal

Abstract: The water management in smart cities is an issue increasingly valued in the context of financial and environmental

sustainability of water supply systems. In addition to the non-return of the investment made in the acquisition, production and

distribution associated with the water losses, the supply systems also have a leading role in the management of the urban water

cycle, and must comply with this element as a feature increasingly scarce on the planet, thus their conservation is also a civic

responsibility. Currently there are increasingly technological innovations capable of making the management of smart water. In

this sense, the main objective of this dissertation was to disclose the technological breakthroughs associated with water use and

the innovations in methodology and monitoring of water losses in supply systems, as well as the benefits that these measures can

offer to the society of today and in the future as well. In addition, an analysis was carried out to the excellent results obtained by

Empresa Portuguesa das Águas Livres (EPAL), the public water Company of Lisbon, due to the implementation of measures for the

monitoring and water losses control in the distribution network associated with a smart water management. The measures

implemented by EPAL are a worldwide reference in smart water management, placing Lisbon at the level of one of the most

efficient cities in terms of non-revenue water. Finally, through the evaluation of the financial effort and savings obtained by EPAL

in the supply network, was estimated what would be the investment required in the monitoring and water losses control in Water

Company, in Porto city, in order to reduce the losses to get sustainable values until 2025.

Keywords: Smart cities; smart water management; smart water system; water supply system; district monitoring areas; water

losses.

1 INTRODUCTION

Since the 1970s, we have observed an increase of

environmental awareness, the evolution of technology and

communications, and the automated production leading to the

need to put environmental issues on the agenda. The report

prepared by the United Nations, entitled "Our Common

Future" emancipates the concept of sustainable development

as the basis for a global economic policy that must go towards

our current needs without compromising those of future

generations (Brundtland, 1987). The water industry has been

subject to changes and opinions with regard to the sustainable

management of urban water. There are many external factors,

including the impacts of climate change, drought, population

growth and its placing in urban centers, which lead to an

increase of the responsibility on providers of water services in

order to adopt more sustainable approaches to the

management of urban waters. The coverage of the costs, the

monitoring of the water without profit and meet the demand

of customers for the fairness in revenues are some of the main

challenges (Boyle et al., 2013).

As is referred to in the Annual Report of the Water and Waste

Sector in Portugal, there are many structural challenges on the

development of modern societies, from the water supply to the

population and economic activities, to the improvement of

urban wastewaters, as well as the management of municipal

waste.

The population growth results in an increase and a

concentration of water needs for various uses and the

consequent need of wastewater and waste management, in

increasingly large amounts. In this reality it is necessary the use

of advanced technologies and the adoption of more robust

management models, that are better suited to the population

demands (Baptista et al., 2009).

2 OVERVIEW OF THE WATER SECTOR

Over the past decades, with the growing water demand, the

risks of pollution and severe water stress in many parts of the

world have increased. The frequency and the intensity of water

crises have increased, with serious implications for public

health, environmental sustainability security in both food and

energy department, and economic development. Although the

central and irreplaceable roles that water plays in all the

dimensions of sustainable development have become

increasingly recognized, the management of water resources

and the provision of services related to the water continues to

be too low in the scale of public perceiving and government

priorities. As a result, the water is often a limiting factor, rather

than a facilitator of social welfare, economic development and

healthy ecosystems. The fact is that there is water available to

meet the growing needs of the world, but not without first

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dramatically change the way water is used, managed and

shared. The global water crisis is a reflection of governance,

much more than with the availability of the resources (WWAP,

2015).

In Figure 2.1 the estimated global hydric availability made by

the World Resource Institute, as reflected in annual flow of

each hydrological basin.

Figure 2.1 – World hydric Availability, (WRI, 2015).

This is not, however, to ensure the supply of water by any

means. Until the year 2000, humans had built approximately

45,000 large dams which, combined with the hundreds of

thousands of smaller structures, quadrupled the storage of

water for human consumption in just 40 years. However, it was

not examined or was able to predict the effects that, on a global

scale, the cumulative construction of dams uncoordinated,

deviations of irrigation and the impacts related to the

deforestation would have on the extension, availability and

quality of water. Today it has become clear that the human

activity started to affect the hydrology of the earth. Our

presence, our actions and its consequences have changed the

very composition of the atmosphere, the precipitation and the

places where the rain falls; the human behavior is affecting the

pattern of rain and snowfall (Sandford, 2012).

The uneven distribution of availability and demand, population

growth, climate change and water mismanagement aggravated

the situation of extreme water stress. The shortage of water is

not only a threat to human and economic development, but

perhaps the main reason for the political instability of the

future.

Figure 2.2 presents a global water stress assessment, exposing

the annual volume captured by municipalities, industries and

agriculture, as a percentage of the hydric availability. Thus, the

higher values indicate the locations that have a higher water

stress, with higher consumption in relation to the availability of

water, where it will be necessary to adopt a more sustainable

approach to water management.

Figure 2.2 – Global assessment of hydric stress, (WRI, 2015).

3 SMART WATER MANAGEMENT IN THE CITIES

3.1 CONTEXT

The smart water management has as objective the exploitation

of water, at regional level or at city level, on the basis of the

ideals of harmony, sustainability and self-sufficiency, through

the use of innovative technologies, such as the water recycling

among other technologies for water treatment, information

technology, monitoring and control technology and through

the implementation of the registration system of the water

cycle to work as a "water flow and information." (Tadokoro et

al., 2011).

3.2 THE CONCEPT OF SMART CITY

The concept of smart city is relatively recent, from the

technological innovations and also of the globalised world in

which we are currently placed in.

A smart city can be defined as the city in which it is performed

an investment in human and social capital, by encouraging the

use of Information and Communication Technology, ICT, as

enabler of sustainable economic growth, providing an

improvement in the quality of life of residents and floating, and

consequently, allow better management of natural resources

and energy. The smart cities will be those who are able to

reconcile the human flows through the new technologies,

mobility and sustainability.

However, it is important to recognize that the concept of smart

city is not limited only to technological advances, but aims to

promote the socioeconomic development. Social inclusion is a

fundamental characteristic of smart cities and all opportunities

for the economic development need to be coupled with

investments in social capital (Colldahl et al., 2013).

The definition of smart cities, by Giffinger et al. (2007), is based

on a Model of Smart City. This model is a system of

classification in which the smart cities can be evaluated and

developed through six distinct characteristics. The Model of

Smart City was developed as a classification tool to assess smart

cities communities of average size in the areas of economy,

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people, governance, mobility, the environment and lifestyle.

Through this model, a city can examine its current state, and in

turn, identify the areas that require further development in

order to meet the conditions necessary for a smart city.

3.3 SMART WATER SYSTEM

The concept of smart water system utilizes advances in

information technologies for system monitoring data and to

achieve greater efficiency in the resources allocation. In

addition to the increased efficiency in the water losses control,

prevention and early detection of leaks, the smart water

system also allows the development of best practice in the

management of assets by improving the efficiency of the

system in emerging areas, such as in the demand-oriented

distribution. Instead of simply following the existing practices

that pump water at high pressure in the distribution system to

reach distant customers, a more smart system could use real

time data, variable speed pumps, dynamic control valves, and

smart meters in order to balance the demand, minimize the

overpressure in aging pipelines and save energy (Global Water

Technologies, 2013).

The use of smart water system to improve the situation of

many networks characterized by degraded infrastructure,

irregular supplies, low levels of customer satisfaction or not

proportional bills to actual consumption. The smart water

system can lead to more sustainable water services, reducing

financial losses and enabling innovative business models to

serve the urban and rural population.

3.4 SMART WATER MANAGEMENT TECHNOLOGIES

3.4.1 SMART PIPE AND SENSOR NETWORKS

According to Lin and Liu (2009) the prototype of the smart pipe

is designed as a module unit with a monitoring capacity

expandable for future available sensors. With several smart

pipes installed in critic sections of a public water system, a real

time monitoring detects automatically the flow, the pressure,

leaks in pipelines and water quality, without changing the

operating conditions of the hydraulic circuit.

The individual sensors knots generally have four main parts: the

data collection and processing unit, transmission unit, power

management and sensors. The performance of each of these

sections, in terms of power consumption and reliability greatly

affects the overall performance of the sensors and the

network. Figure 3.1 illustrates a general diagram of smart pipes

and wireless sensor network.

Figure 3.1 – Scheme of a smart pipes and wireless sensor network,

(Sadeghioon et al., 2014).

Briefly, the smart wireless sensor network is a viable solution

for monitoring the state of conservation, the pressure and the

water losses control. The main advantage compared to other

methods of water losses control normally used is the

continuous monitoring throughout the network, without

operator intervention. Another advantage is the low energy

consumption of the wireless sensor network, allowing them to

remain operational for long periods without maintenance,

(Sadeghioon et al., 2014).

3.4.2 SMART WATER METERING

A water meter is a device used to measure the quantity of

water consumed in a building, while a smart metering is a

measuring device that has the ability to store and transmit data

consumption with frequency (Figure 3.2). Sometimes, the

smart metering is referred to as the "time of use in m3",

because in addition to measuring the volume consumed, also

records the date and time that the consumption occurs.

Therefore, while water meters are read monthly or twice a

month and a water bill is generated from this manual reading,

the smart metering can be read from a distance, and with

greater frequency, providing instant access to information on

the consumption of water for customers and managing entities

of the water supply network. These smart water meters are a

component of the Advanced Metering Infrastructure (AIM) that

water companies should choose to install (Alliance for Water

Efficiency, 2010).

Briefly, the smart water metering offers essentially the

opportunity to improve the balance between the provision of

access to drinking water, the right of a managing entity to be

payed for services rendered, as well as the joint responsibility

of all to conserve the already scarce water resources (Boyle et

al., 2013).

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Figure 3.2 – Scheme of the smart water metering technology

(Alliance for Water Efficiency, 2010).

3.4.3 GEOGRAPHIC INFORMATION SYSTEM – GIS

As regards the implementation of a Geographic Information

System (GIS), it must be understood that this tool can be

applied to various areas of study and, when applied to smart

water management technologies, allows us to have a clearer

idea of its evolution. The major advantage of a GIS is the

modulation of reality based on data and assumes a prominent

role in today's society because they are information systems

designed to collect, styling, store, receive, share, manipulate,

analyze and present information that is geographically

referenced (Worboys & Duckham, 2004).

The GIS plays a strong role in smart water management and for

the management entities, already provides a more complete

list of the components of the distribution network and their

spatial locations. With a sophisticated network communication

overlay on the water supply system, the data management with

GIS becomes absolutely critical.

Geographic Information Systems (GIS) allows incorporating the

spatial component to a model object oriented, allowing an

improvement in the planning and management of systems of

public networks and facilitating a clear evolution of spatial

models in the network.

3.4.4 CLOUD COMPUTING

The concept of cloud computing refers to the use of memory

and storage capacities and calculation of computers and

servers shared and linked through the Internet, by following

the principle of network computing.

The storage of data is done in servers which can be accessed

from anywhere in the world, at any time, without the need of

installing programs or storage of data in other devices. Access

to programs, services, and files is remote, via the Internet -

hence the allusion to the cloud. The use of this model is more

viable than the use of physical drives.

Furht and Escalante (2010) defines cloud computing as "a new

style of computing in which the resources are dynamically

scalable and often virtualized being provided as a service over

the internet" such as large repositories of virtualized resources,

such as hardware, development platforms and software, which

are easily accessible and can be dynamically configured so as to

adapt to different workloads with the intention to optimize

their use.

3.4.5 SUPERVISORY CONTROL AND DATA ACQUISITION –

SCADA

In general, the majority of public water services have embarked

on an online monitoring where the supervision, control and

data management is done through the system, known as

SCADA (Supervisory Control And Data Acquisition) (EPA, 2009).

In this way, SCADA is a system that allows an operator in a

central location in processes widely distributed will be able to

make changes to the set point in distant process controllers, to

open or close the valves or switches, to monitor alarms, and

gather information from measurement (Boyer, 2004).

Up to date, the more detailed data about the current state of

the water network in terms of flow, pressure and water quality

is collected using the SCADA systems located in reservoirs and

water tanks. Generally, has very limited surveillance

capabilities, online analysis and limited implementation in

pipes and valves within the water distribution networks.

In short, the SCADA systems are used to control dispersed

assets acquisition of centralized database where it is just as

important as the control. These systems of supervision, control

and management of data are used in various systems of

distribution, such as the distribution of water and waste water

systems, oil and gas pipelines, transmission concessionaire of

electrical power and rail and other public transport systems.

3.4.6 MODELS, TOOLS OF OPTIMIZATION AND DECISION

SUPPORT

The implementation of a common framework for measuring

performance based on a set of relevant indicators and data

applications and interfaces to support the decision of the

managing entities allows the interested parties to learn from

each other, to create trust and confidence in the solutions and

to monitor the progress (Airaksinen et al., 2015).

The hydraulic network and water quality models represent the

most effective and viable way to predict the behavior of the

water distribution system under a wide range of conditions of

demand and system failures.

In the other hand, the models of operations in real time

optimization (real time operations-optimization models),

expand the use of the smart water system in order to help

operators to improve the efficiency of the water network and

ensure more reliable operations and maximizing cost savings.

The models automatically read the data in real time, instantly

update the network model, show the characteristic parameters

of pump and treatment stations as well as the hours of

operation that will produce the lowest operating costs,

provided that they meet the objective requirements of the

system (Boulos & Wiley, 2013).

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3.5 ADVANTAGES OF THE SMART WATER MANAGEMENT

Some of the main advantages of smart water management are

a better understanding and analysis of water system, detection

of leaks, conservation and monitoring of water quality. The

implementation of the smart water system technologies allows

public services companies to be able to build a complete

database. In fact, having a detailed database also allows the

identification of the areas where water losses occur, enabling

public services companies to identify leaks and/or illegal

connections. The advantages of the smart water grid are

varied: from economic benefits, to water and energy

conservation, among others. In addition to the benefits listed

above, the efficiency of the system can improve customer

service. The wireless data transmission allows the client to

analyse his water use and potentially use water with a view of

persevering this resource. In fact, the consumers who chose the

electronic bill have reduced in a more significant and active way

its water consumption, in some cases, as high as 30%

(Martyusheva, 2014).

3.6 HITACHI: A RENOWNED COMPANY IN THE MARKET

Throughout the world, specific measures are being taken to

achieve a special type of city: the Smart City. In order to do so,

there are numerous companies associated with this

commitment, where Hitachi stands out among other large

international companies such as IBM or Schneider-Electric.

In April 2010, Hitachi has created an entire division focused on

smart cities. The Division of Innovation Projects and Social

Enterprise is based on experience and knowledge of the

companies in the group Hitachi. These companies have been

developing a wide range of social infrastructures, equipment

and information systems for the cities over many years. The

division aims to contribute to initiatives of a Smart City and

work with Japanese and foreign partners, developing and

promoting businesses related to the Smart Cities. Through

these companies, Hitachi helps cities to plan, implement and

develop systems that can operate efficiently solving current

problems. But, the visionary approach of Hitachi, is not only to

help make the cities more technologically advanced. The close

technological solutions rarely satisfy all interested parties of a

city, which include the city's administrators, residents,

companies, and those who manage it, meaning that the

stakeholders of a city often have different goals and focus on

different themes. The approach of Hitachi is to find solutions

that provide the ideal balance between all these interested

parties and specially to ensure the comfort and the

sustainability of society itself. Hitachi takes into account firstly

the economic characteristics, environmental and social issues

that the city faces and then helps to provide Smart cities

solutions to help solve the specific issues of that city. The main

objective is not only to solve the current problems, but also to

make the devolved systems simpler to enable solving future

problems (Hitachi, 2013).

4 CASE STUDY – SMART WATER MANAGEMENT

4.1 GENERAL CONTEXT

Currently there are more and technological solutions capable

of making the management of smart water and in this chapter

it will be shown an example, worldwide, of the smart water

management, made by a Portuguese company EPAL – Empresa

Pública de Águas Livres (Public Water Company) – in the

Portuguese capital. In Lisbon, the company has focused the

world's attention, due to the high level of efficiency,

particularly in the reduction of water losses and consequently

the reduction of operational costs.

In historical terms, the origin of EPAL was in 1868 with the

creation of the Companhia das Águas de Lisboa, CAL, the

concessionaire of water supply of the city of Lisbon during more

than 100 years. Only on April 21, 1991, by the decree-law no.

230/91, EPAL is transformed into an incorporated company of

capital fully public, taking advantage of the flexibility of

management required to implement the strategy of

development, going by the name of Empresa Portuguesa das

Águas Livres, S.A.. From 1993 is integrated in ADP Group –

Águas de Portugal SGPS, SA., and currently it is a company of

the State enterprise sector, 100% owned by ADP (EPAL, 2015).

The EPAL Company manages and operates a supply system that

integrates three subsystems: the Castelo de Bode, opened in

1987 and currently has a daily production capacity of

approximately 625,000 cubic meters, the Tejo, inaugurated in

1940, with daily production capacity of 400,000 m3 and the

Alviela which is in operation since 1880 (EPAL, 2015),

represented in Figure 4.1.

In terms of infrastructure, the water supply system in Lisbon

comprises 2 Surface water extractions, 23 groundwater

extractions, more than 700 miles of adductor pipelines, 28

reservoirs, 31 pumping stations and 21 posts of chlorination, 7

associated with the treatment and 14 associated with the

strengthening of chlorination.

The chlorination posts are composed of 18 chlorine dosage

posts and 3 sodium hypochlorite dosage posts (EPAL, 2013).

The water distribution network in the city of Lisbon is

composed of approximately 1,400 km of pipelines, with more

than 100,000 connection branches, 14 reservoirs, which allows

to store more than 400,000 cubic meters and 10 pumping

stations (EPAL, 2014b).

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Figure 4.1 – EPAL’s Supply network, (EPAL, 2013).

In the context of the market for the provision of water supply

services, according to the annual report for 2014, EPAL

comprises an area of 7,095 km2, with 347,151 direct clients, 17

municipal clients and 3 multimunicipally clients, who represent,

as a whole, 35 municipalities (including Lisbon), involving more

than 2.8 million clients (EPAL, 2014b).

These values correspond to a volume of water sold higher than

192 million cubic meters, with the indicators of financial

turnover and net profits for the period exceeding EUR 140

million and EUR 54 million, respectively (EPAL, 2014b).

In spite of this, the non-revenue water was always a problem

for EPAL, which during the 1990’s, the overall volume of non-

revenue water has stabilized at around 50 million cubic meters,

with a strong predominance of the losses in the distribution

network, Figure 4.2.

Figure 4.2 – Non-revenue water register by EPAL, (EPAL, 2014a).

According to the International Water Association, IWA, the

volume of water in the distribution system, whether imported

or extracted drinking water, is divided into billed water (BW)

and non-revenue water and even between the authorized and

unauthorized consumption. In a simplified form it may be

considered the billed water as the water charged to direct

clients added to water that is exported to other water entities,

which is actually the consumption that is effectively authorized

and billed. The non-revenue water includes not only the water

losses, but also the volume consumed by the supplier or

authorized agents, due to social commitments and the

legitimate use of fire service. A simplifying schematic of this

hydric balance in the supply system is presented in Figure 4.3.

Figure 4.3 – Hydric Balance, according to IWA.

The water losses at supply systems reflect a measure of the

quality of management and operation of the system and

consequently EPAL, as all the managing entities of water supply

systems, strives to control and reduce the volume of water lost.

As it can be seen in Figure 4.3, the water losses may be of two

types, apparent or real. The apparent or economic losses

correspond to illegal or theft consumption, while the real or

physical losses correspond to losses through leaks, ruptures or

burst pipelines, reservoirs or service connections up to the

point of where the client connects to it.

To emphasize that despite the increased monitoring and

control associated with technological advances, it is not

possible to calculate accurately through measurements the

volumes associated with each of the categories described

above. Therefore, when necessary, it turns to estimates or

extrapolations from existing records.

Due to heavy losses in Lisbon’s distribution system in the

1990s, which placed Lisbon far of the best cities in terms of non-

revenue water, EPAL has set the ambitious goal of reducing the

non-revenue water in Lisbon distribution network to

sustainable values, setting a goal of water losses of less than

15% by 2009, Figure 4.4.

Figure 4.4 – More Efficient Cities in terms of non-revenue water in

the 1990’s. EPAL’s goal for 2009, (EPAL, 2014a).

As it can be seen in Figure 4.4, the losses were stabilized at

about 25% of the collected water, and in order to reduce the

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losses in a decade for values less than 15 %, EPAL adopted a

well-defined strategy that focused on:

• Segmentation and continuous monitoring of the network;

• Development of analysis systems using internal resources;

• Optimization of the process of active water losses control;

• Continuous improvement based on the experience and results;

• Review process simple and effective given the complexity of distribution systems;

• Focus on essential and real cost control.

In relation to the water losses control, this strategy tries to

reach the Economic Losses Level (ELL). The ELL is the objective

value of management entities, in an attempt to minimize the

overall cost associated with the water lost in the system and

the activities carried out under the active water losses control,

meaning, the maximum investment in an attempt to reduce

water lost, that from which it is no longer economically viable,

because it is higher than the cost of water lost. In Figure 4.5 the

concept of ELL in a simplified manner.

Figure 4.5 – Scheme on the Concept of Economic Losses Level,

(Sardinha, et al., 2015).

In order to reduce the losses in the water distribution system,

EPAL has to improve the monitoring and control of water losses

in the supply system of Lisbon since the 1990s. Thus, EPAL has

developed key tools for the deployment of a monitoring system

that does not put in question the supply, in quantity and

quality:

• Geographical Information System (GIS);

• Management Information System for Customers (MISC);

• Digital Terrain Model (DTM);

• Hydraulic System Model.

In addition, EPAL measures District Monitoring Areas (DMA),

being that the strategy of sectorization and monitoring of the

network is based on the total distribution of the network by

sectors that can be analysed independently. The sectorization

of the network makes it possible to obtain advantages in terms

of quantity and quality of information available on the network

and its operation, the identification of consumers of each DMA

and abnormal night consumption and the management and

control of pressure in the distribution water network.

The IWA recommends that an DMA should have between 1,000

and 3,000 clients, but in urban areas with high population

density, such as the present case study, may group together

more than 3,000 clients, with a maximum limit of 5,000 clients.

This limitation relates only to the increased difficulty in the

identification and location of ruptures to DMA of higher

dimension.

In this context it may be subdivided if the DMA in relation to its

size in three categories: small, with less than 1,000 clients,

medium, between 1,000 and 3,000 clients, and large, with

more than 3,000 clients. These values are not universal and

absolute, but have been tested and validated for the case of

Lisbon. In this case, the distribution network is divided into 152

DMA as it is presented in Figure 4.6.

In order to carry out the collecting, management and

processing of the information of the water supply system of

Lisbon, EPAL uses various registration systems and

transmission of data, in particular data-Logging equipment.

These devices enable the automatic collecting data water

consumption, pressure, among other variables, through

meters, flow measurement or probes (pressure sensors, pH or

chlorine) directly installed on the network. The data collected

are transmitted remotely, through such devices to a central

database, where they are stored, offering to the managing

entity scans and records more frequent and reliable, reducing

the need for estimates.

In this context, EPAL has developed a system for the monitoring

and water losses control based on the DMA and data collected

remotely, that allows you to combine processes and integrate

the information relevant to the management of the network,

the WONE - Water Optimization of Network Efficiency.

The main objective of the WONE is to support the strategy of

EPAL in search of the optimization of the supply system,

focusing on efficiency and reduction of losses, providing

performance indicators of DMA. This software provides an

intuitive interface using internet, allowing multiple users at the

same time, besides it becomes possible to integrate other

management systems (GIS and MISC), aiming to the needs of

different areas of the management entity, and still allow the

statistical calculation, graphical presentation and alarms

integration. Thus, WONE integrates perfectly in the process of

optimization and improvement of the efficiency of the

distribution system deployed by EPAL, which is presented in

Figure 4.7.

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Figure 4.6 – District Monitoring Areas, DMA, Lisbon, (EPAL, 2013).

Figure 4.7 - Optimization and Efficiency improvement Process,

(EPAL, 2014b).

Finally, it should also highlight the effort of EPAL in

implementation of flow meters indicated for each strategic

location on the network, such as for example the entry and exit

of DMA, and the methodologies and innovative strategies for

the detection and localization of leaks, essential for the rapid

action and consequent reduction of water losses in the system.

4.2 RESULTS ANALYSIS

The analysis of this case study will be carried out based on the

results obtained by EPAL in the last decade, by considering this

time interval the most relevant for assessing the effects of the

measures implemented in the distribution system.

The implementation of the monitoring measures and active

water losses control in Lisbon’s supply system, allowed EPAL to

reduce the losses in the system by 17 %, in 2004, to less than

10% of the total volume captured in 2014, Figure 4.8.

Figure 4.8 – Non-revenue Water evolution at EPAL.

As it can be seen in Figure 4.8, there was a decrease in the

volume of non-revenue water in this decade, 45.7 Mm3 for 19.9

Mm3. This decrease was due mainly to the efforts of the EPAL

logged to control the losses in the distribution system, because

the losses in production and transport remained constant at

approximately 5% of the volume of the collected water. On the

other hand, the NRW in distribution system decreased by more

than 30 Mm3, in 2004, to approximately 8 Mm3 in 2014. It is

presented this significant evolution in water losses control in

the distribution system of EPAL in Figure 4.9, where it also

stands out that approximately half of the volume of water

produced is delivered to other management entities.

Figure 4.9 – Evolution of the hydric balance in EPAL’s supply system.

As mentioned, the policy of monitoring and water losses

control of EPAL has focused in particular on the distribution

system, for this have levels of NRW too high in comparison to

the system of production and transport. The strategy of EPAL

has enabled the reduction of the levels NRW in Lisbon

distribution network of 23.9 %, in 2004, to 8.1 %, in 2014, Figure

4.10. This decrease in the volume of NRW of 27 %, from 30 Mm3

to 8 Mm3, in 10 years, it is even more significant considering

the significant reduction in the total consumption.

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Figure 4.10 – Results of the policy of active water losses control in

the distribution system of EPAL.

As previously mentioned, EPAL defined at the end of the 1990s

the ambitious goal of reducing the non-revenue water in Lisbon

distribution network for sustainable values, setting a goal of

water losses of less than 15% by 2009. As it can be seen in

Figure 4.10, this objective has been achieved, and at this

moment the management of the distribution system of Lisbon

positions the EPAL in elite group of more efficient management

entities worldwide, Figure 4.11.

Figure 4.11 – More efficient Cities at non-revenue water level in

2014, (Sardinha, et al., 2015).

Associated with the efficiency gains, EPAL had still a decrease

in operating costs of supply network, shown in Figure 4.12.

Despite the reduction of these costs, the unit cost of water

produced was not sensitive to this variation and remained close

to the €0.30/L. This is mainly due to fixed costs of supply

network, the decrease in demand and an increase in this

decade of unit costs of External Supplies and Services (ESF), in

particular the electricity.

Figure 4.12 – Operational Costs and unitary cost of produced water.

Still the energy bill, which is the main constituent of the ESF,

contradicted the trend of growth in the market, due to the

gains associated with the energy optimization enabled by

monitoring and water losses control. In 7 years EPAL obtained

an energy saving of approximately 57 GWh, reducing the

energy bill by more than EUR 5 million. In addition to the energy

reduction, another more direct result and representative of the

policy of monitoring and water losses control, was the

reduction of the levels of NRW in the network, which allowed a

saving, in 7 years, about 100 Mm3, or EUR 50 million.

These results demonstrate the improvement of the efficiency

of the exploration of the supply network of Lisbon, with a

savings of more than EUR 55 million in just 7 years. For this, it

was necessary to invest in the sustainability of the distribution

network and in new technologies of information and

communication. In total, EPAL has invested approximately EUR

18 million in 10 years, approximately 5% of the total investment

in this period, to reach these levels of efficiency, Figure 4.13.

Figure 4.13 – Investment in water losses control and their financial

accumulated gains.

As it can be seen conclude by looking at Figure 4.13, the

investment made in monitoring and water losses control

obtained a recovery of investment in short term, allowing

further reduction in the overall costs in the operation of the

network, offering a saving of about EUR 37 million in 10 years

of operation.

But the investment is not linearly related with the financial

gains and EPAL defines the needs of investment through the

systematic calculation of the ELL, noting that the levels of actual

losses in Lisbon network reached at this moment this value. As

such, and recalling that the ELL is the objective value of

management entities, in an attempt to minimize the overall

costs associated with the water losses in the system and the

activities carried out under the active water losses control,

meaning that the maximum investment in an attempt to

reduce the water losses, that from which is no longer

economically viable, because it is higher than the cost of water

lost, is not justified at this present time, a financial effort. It

should be noted, that this situation can be changed at any time,

due to this value is sensitive to situations such as network

changes, legislation, consumptions, personnel and ESF costs as

well as the macroeconomic situation of the country.

10

Thus, the supply network has evolved into an economic,

financial and environmental situation more sustainable, which

is an objective that EPAL is proposed to achieve, and that all

other entities are looking for in the context of smart cities.

5 CORROLATION MODEL FOR ÁGUAS DO PORTO

5.1 GENERAL CONTEXT

The Águas do Porto of Porto’s City, Municipal Company, derives

from the Municipal Services of Water and Sanitation of Porto

(MSWSP), founded in April 1927. Currently, it has the granting

of water distribution and drainage of wastewater in the

municipality of Porto. It has a total of about 150,812 clients.

The system of water distribution to the city, Figure 5.1, is

composed of 6 reservoirs - Bonfim, Carvalhido, Congregados,

Nova Sintra, Pasteleira e Santo Isidro - which corresponds to a

total storage capacity of 125,450 m³, by a network of

distribution pipes with 718 km in length and by a set of

adductor pipelines whose length is 42 km. The distribution

network has approximately 64,000 domiciliary service

connections and the water distributed has origin at the

collecting point of Águas do Douro e Paiva, S. A., and is supplied

to the city of Porto by 12 points of delivery for the system at

low point (distribution network), which are distributed along

the two main adductors’ axis, a North along the Circunvalação

road and another to the South, which supplies the Reservoir of

Nova Sintra.

Figure 5.1 – System of adduction and distribution of supply network

of Porto City (Águas do Porto, 2015).

Through the success of the Project Porto Gravítico (2006-2012),

it was feasible to make the gravitational supply almost on the

whole, through restructuring the distribution network, in order

to extinguish the service of four pumping stations (Bonfim,

Nova Sintra, Pasteleira and Santo Isidro) of the municipal

system, maintaining currently active only the pumping station

of Congregados, to fill the area of higher quota city - DMA

Congregados Superior - whose gravitational supply is not

possible, for reasons associated with the topography of the

land.

At the moment, the distribution network of the city of Porto is

divided into 18 DMA. The company has opted for the

sectorization of the distribution network through the creation

of interior sub-DMA so that it is possible to carry out a more

effective monitoring and consumption control. Proof of this is

the fact that, in addition to the already existing 18 large DMA,

the water distribution network of Porto City is subdivided into

31 interior shut down sub-DMA.

5.2 CORROLATION MODEL

Considering the results obtained by EPAL in the optimization of

distribution network through the improvement of monitoring

and control of losses, it was estimated that the investment

required in order to be possible to obtain an equivalent level of

performance in the system of water supply from Porto’s City,

meaning for losses in the distribution network less than 10% by

2025, as previously set above. Therefore, the main

characteristics of the current system of distribution of Porto’s

City were assessed, Table 5.1.

Table 5.1 – Main characteristics of Águas do Porto distribution

system, (Águas do Porto, 2014).

Total Annual Volume (m3) 20 332 815

BW (m3) 15 962 429

NRW (m3) 4 370 386

(%) 21,5%

Total Clients - 150 812

As we can see in Table 5.1, the NRW in Águas do Porto

Company in the year of 2014 stood at 21.5 %, with more than

4 Mm3 non-revenue water, this amount being equivalent to

that which EPAL (Public Water Company in Lisbon) had in 2004,

but higher in comparison with the level that EPAL managed to

achieve in 2014. The level of NRW was the main factor of a

discriminant analysis that allowed determining the Águas do

Porto as the indicated entity to apply the correlation model.

The other factors that were also mostly favourable were the

initial level of implementation of DMA, the similar water

consumption diagram of Oporto and Lisbon and the equivalent

level of environmental awareness of both cities in terms of

energy and water management.

Thus, it was considered that the development of EPAL suffered

between 2004 and 2014, at the expense of the investment

made in monitoring and water losses control, could be

transposed to the distribution system of Porto’s City using the

method described in the flowchart in Figure 5.2.

11

Figure 5.2 - Flowchart of the correlation model.

As can be seen in Figure 5.2, the EPAL data was used to

estimate the major socio-economic indicators for determining

the investment required to reach a certain NRW level.

A statistically analysis to key indicators of the EPAL results for

the correlation model were made, in order to determine the

annual growth rates of the number of clients and billed water,

and the Investment in water losses control per reduced volume

of NRW and per client. Note that the determination of those

parameters per client are essential to correlate different size

water management companies, since they may have different

sizes but usually proportional to the number of clients.

The annual growth rate of the number of clients was obtained

through the average annual growth recorded by EPAL from

2004 to 2014, as the mean squared error (MSE) determined

from different types of regressions did not present acceptable

values to be considered a reliable indicator to the progress of

this parameter. Since so it was adopted an annual growth rate

of 0.3% for this correlation model.

In order to determine the billed water progression it was first

made a canonical correlation taking into account the evolution

of the number of clients in the distribution system on an

attempt to assess the dependence of billed water with the

number of clients.

As seen in Figure 5.3, there is no correlation between the

annual growth in the number of clients and the BW on the

results of EPAL, verifying that these are independent

parameters.

Figure 5.3 – Correlation between the annual growth rate of billed

water and number of clients.

Thus, it was evaluated the possibility of BW present a growth

that could be represented by a linear regression, polynomial or

logarithmic. The reduced value of MSE not allow it to take some

of these regressions as a parameter of the correlation model,

and taking this into account it was adopted the average growth

rate of BW, -0.3%. Note that it was determined that these

variables are independent, making from the outset the demand

a multivariate model, in terms of number of customers and BW.

The search model has allowed determining the evolution of the

number of customers and volume of BW at Porto supply

system.

Finally, it was analysed the correlation between the annual

investment per client effected by EPAL in the study decade with

the decrease of NRW by client of the following year. It was

considered with this analysis that the investment made in a

year on water losses control would only return results in the

following year. This analysis would be able to determine a

logistic regression for the investment required per client to

achieve a certain level of NRW, but the MSE values were not

considered acceptable to determine investment by this means.

AN

NU

AL

GR

OW

TH R

ATE

OF

BIL

LED

WA

TER

ANNUAL GROWTH RATE OF NUMBER OF CLIENTS

12

In this way it was determined the investment parameter's in

the water losses control per volume of NRW reduced and per

client with the average value of annual investment by reduction

of NRW of the following year and per client by the following

equation:

𝐼𝑁𝑉𝑁𝑅𝑊̅̅ ̅̅ ̅̅ ̅̅ ̅̅ =

∑ 𝐼𝑁𝑉𝑖𝑁𝑅𝑊𝑖+1⁄𝑛

𝑖=1

𝑛

(1)

that,

𝐼𝑁𝑉𝑁𝑅𝑊̅̅ ̅̅ ̅̅ ̅̅ ̅̅ – Annual investment average on water losses

control by decrease of NRW and by client;

𝐼𝑁𝑉𝑖 – Investment on the water losses by client in the year i;

𝑁𝑅𝑊𝑖+1 – Non-Revenue Water per client of the year i + 1.

The value obtained for the Investment parameter on the water

losses control by volume of NRW reduced and per client was

3.6 € / m3 / client / year.

With the parameters of the correlation model obtained was

even necessary to determine the volume corresponding to the

NRW goal level in 2025. From the BW and the NRW level

intended is possible to determine the volume of NRW and

water in the system for the year 2025, but to evaluate annually

the evolution of the system was assumed that the AP would

make an investment that allow a reduction in the volume of

NRW, constant until 2025. With the determination of the

evolution of the distribution network of Porto city, and as can

be seen in flowchart that appears in Figure 5.2, it were

determined all the parameters required to make the

determination of annual investment in the water losses control

needed to reach the NRW goal of 10% until 2025.

5.3 RESULTS ANALYSIS

After the determination of the correlation model indicators, it

was possible to relate the decrease of NRW per year with the

annual investment in the water losses control required in the

previous year, obtaining the investment plan and the evolution

of the distribution network features the next 10 years.

The total investment required in the AP, obtained through the

correlation model considering the indicators previously

determined was approximately 9.5 M € for the next decade,

allowing a reduction of more than 2.6 Mm3 of NRW in 10 years.

Are set forth in table 5.2 the main values obtained from the

correlation model, where highlights the level of NRW losses

and the total investment.

Table 5.2 – Estimate on the evolution of the main features in Águas

do Porto, based on EPAL.

Main features

Águas do Porto EPAL

2015 2025 2004 2014

Total Annual

Volume (Mm3) 20,3 17,3 127,0 101,0

BW (Mm3) 16,0 15,5 96,6 92,8

NRW

(Mm3) 4,4 1,7 30,4 8,2

(%) 21,5% 10,0% 23,9% 8,1%

Total Clients - 150 812 155 293 339 111 349 151

In Figure 5.4 and Figure 5.5 are represented some results

obtained graphically, allowing an immediate evaluation

of the evolution of NRW level in the Porto distribution

network and the required annual investment. In Figure

5.4 is presented the investment plan and the variation of

NRW level for the next 10 years, while the figure 5.5

represents the evolution of the water volumes associated

to NRW and BW in Porto distribution network.

Figure 5.4 – Investment in water losses control and the

corresponding evolution of the NRW to Águas do Porto Company.

Figure 5.5– Evolution of losses in the Distribution system of Águas

do Porto Company.

13

6 CONCLUSIONS AND RECOMMENDATIONS

6.1 CONCLUSIONS

In this present research, it is concluded that the technology

itself does not make a city a smart city, since it is necessary to

create a proper system to each city and efficient use of

innovative technologies associated with a worldwide

awareness of the society in relation to the sustainable

management and use of available resources. Through the

technological innovations, the smart cities can reduce costs,

increase quality and optimize different characteristic

parameters.

The water sector presents significant challenges, in particular

the effort to develop a smart water system, which translates to

a better control and monitoring of the network in order to

improve the efficiency of the system. According to the Global

Water Technologies (2013), the public water services need new

technologies to monitor our systems - providing real time

measurement of water consumption and warnings when the

conditions become critical.

The potential benefits of a smart water management include

the improvement of the water losses management, monitoring

of water quality, better management of droughts, and energy

savings. Thus, the smart water management in the cities is a

great way for the conservation, efficiency, and security

objectives to be achieved, once that Ervideira refers (2014)

"The non-revenue water translates annually in millions of

euros, translated into work expenses, chemicals and non-

recoverable energy ".

In this case study it was analysed the results achieved by EPAL

during the implementation of the measures for the monitoring

and water losses control in the distribution network of Lisbon.

The results obtained allowed to assess the high level of

efficiency achieved, in particular the reduction of water losses

and consequent reduction of costs, and associate it to the

investment made during the last decade.

This analysis allowed us to evaluate the efficiency gains and

savings in water that EPAL has achieved through the measures

that aim to optimize energy efficiency and reduce water losses.

Not only the levels of non-revenue water reached values in the

category of more efficient cities in the world, as the profits of

the company have been presenting historical highs.

Thus, it should be emphasized that the investment of EUR 18

million of EPAL policy on monitoring and water losses control

allowed the saving of approximately 57 GWh and 100 Mm3,

corresponding to an overall saving of more than EUR 37 million

in just 10 years.

Of further note, that at this moment the EPAL has reached the

maximum value from which is no longer economically viable

investment in water losses control, which is higher than the

cost associated with the lost water, meaning that it reached the

NEP. Thus, there is no need for additional effort in this area,

focusing on the EPAL stabilization of pressures and control of

transitional arrangements, with the aim of continuous

improvement of the operation of the system of distribution. It

should be noted, that the calculation of the Economic Losses

Level (ELL) is systematic and being sensitive to situations such

as network changes, legislation, consumptions, personnel costs

and External Supplies and Services (ESF) and, of course, the

macroeconomic situation of the country, may at any time

return to be an economically viable investment in water losses

control.

Finally, in relation to the excellent results obtained by EPAL, it

was estimated the investment necessary to achieve the goal of

water losses inferior to 10% by 2025, in the distribution

network of Porto Water Company. Despite the clear

differences in terms of the topography and the size of the

distribution systems, these systems had similarities that allow

a correlation of the results obtained by EPAL, specially taking

into account that the level of losses of EPAL in 2004 (23.9 %)

was comparable to Porto Water Company (21.5 %) in the

present. It was taken into account the fact that in 2004 EPAL,

as the Porto Water Company at the moment, had already

started the implementation of measures for the monitoring

and water losses control. With these assumptions, it was

considered that it would be more accurate the correlation of

the results obtained by EPAL for the distribution system of

Porto City in relation to the analysis of historical data of Porto

Water City to estimate the evolution of this system.

In this sense it is estimated that a total investment of around

EUR 9.5 million until 2025 would be sufficient to reduce the

losses in the distribution system of Porto City to 10 %, placing

the city at the level of the most efficient in the world.

6.2 RECOMMENDATIONS FOR FUTURE DEVELOPMENTS

As a result of this work appeared some aspects that proved

interesting for a more detailed approach. As the very

philosophy of sustainable management presupposes, it should

be continuously investigated points to be improved in the

process of looking for more efficient systems. In this sense, it is

recommended to perform a detailed analysis on the DMA for

different cities. The DMA, as stated, may have quite varied

characteristics, since geographical dimension, number of

clients, topography and infrastructure. Thus, increasing the

level of detail in the investigation of quality of service, losses,

investments and operating results, will allow an observation of

direct results of investments made in each DMA. The creation

of a database of results of DMA will allow the creation of

models of correlation at the level of DMA, instead of the

distribution system, allowing a financial analysis more accurate

and up to the level of infrastructure investment, maintenance

and operation of the network.

At this point it is also important to point out the importance of

the use of equipment and technological systems in innovative

exploitation of water distribution network, as key tools for a

14

smart water management, in particular smart pipes, sensor

networks, smart meters, cloud computing, SCADA,

geographical information systems and models of optimization

and decision support. All such equipment and systems referred

to will allow the collection, integration and processing of data

in real time and on a continuous basis, which enables an

efficient management in control and monitoring of water

losses and leaks, in control of obstructions to flow in conducts

and a more effective maintenance of infrastructure network by

preventing the degradation and premature aging of the same.

Finally, as is the case in the city of Lisbon, other cities should

proceed with the integration and development of policies in

the maturation of the water use, in particular the energy saving

and recycling of water and awareness of the increasingly

limitation this resource faces. This maturation of society is

essential for the successful implementation of a smart water

management.

15

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