Decision Analysis Project: Singapore Fifth NEWater Plant - Analysis

This project analyzes the Singapore Fifth NEWater plant, focusing on the application of decision analysis tools to a real-world environmental engineering problem. The project begins with a problem statement and sets objectives related to water security and sustainable development. It then constructs a decision tree to evaluate various scenarios and expected values. Risk profiles are developed to assess uncertainties and potential challenges. The analysis explores key uncertainties, including technological advancements, water demand projections, and climate change impacts. Trade-offs between land use, energy consumption, and water resources are considered. The project culminates in recommendations for the NEWater plant, emphasizing sustainable practices and long-term water security strategies. The report uses publicly available information and secondary research sources, providing a comprehensive decision analysis of the project.

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/322915336
Quest for Water Security in Singapore
Chapter · February 2018
DOI: 10.1007/978-981-10-7913-9_4
CITATION
1
READS
271
2 authors:
Some of the authors of this publication are also working on these related projects:
Comportamiento por-ambiental y bienestar subjetivo: Hacia un desarrollo sostenibleView project
Water GovernanceView project
Cecilia Tortajada
Lee Kuan Yew School of Public Policy
376PUBLICATIONS1,671CITATIONS
SEE PROFILE
Cheryl Wong
National University of Singapore
2 PUBLICATIONS1 CITATION
SEE PROFILE

Chapter 4
Quest for Water Security in Singapore
Cecilia Tortajada and Cheryl Wong
AbstractFor decades, the main goal of Singapore in terms of water resources
been to become water-secure.As a result,wateravailability,accessibility,and
affordabilityhave traditionallybeen decidedat the highestpoliticallevel.
Singapore’s overall development is linked to a great extent to ‘blue developm
the amountof water available in sufficientquantity and quality and ataffordable
prices for the growing number of uses and users in every sector. The city–sta
to be water-secure,self-sufficient,and resilient by 2060,when water consumption
will be twice today’s level.An importantglobalcity,Singapore willcontinue
improving its economic and social conditions to match both local expectation
globalprospects.Trends indicate thatit will become more urban,more industri-
alised, and more competitive, which will result in higher water demand. Know
its key policies and innovations, Singapore will have to continue planning with
long-term framework to become water-secure and achieve its overall develop
goals.
4.1 Introduction
Singapore is a city-state of 719.2 km2 in Southeast Asia. It has a total population of
5.6 million and a population density of7797 personsper km2 (Singapore
Department of Statistics 2017a).
Singapore has to be considered within its own context: a small island, and
area-constrained, that has grown continuously only through land reclamation
no natural resources and no hinterland to provide them, and a historical depe
on outside sources of water, energy, and food. These seemingly serious limita
havebeen overcome,however,with long-term comprehensiveplanning,key
C. Tortajada (&) C.Wong
Institute of Water Policy,Lee Kuan Yew School of Public Policy,
National University of Singapore,Singapore,Singapore
e-mail: [e-mail]
© Springer Nature Singapore Pte Ltd.2018
World Water Council (ed.),Global Water Security,Water Resources
Development and Management,https://doi.org/10.1007/978-981-10-7913-9_4
85
[e-mail]

policies,and innovation in allthe sectors,where the overalldevelopmentof the
city-state,rather than the individual sectors,has been the main priority.
Since independence,when planning for water resources,water security (avail-
ability,accessibility,and affordability) has been a main consideration.To become
more water-secure,the city-state has developed forward-looking,comprehensive
strategiesthathaveensured thatSingaporecan meetpresentand projected
requirements (Tan et al. 2008). These strategies have included all aspects of
resources policy,planning,management,development,governance,finance,tech-
nology,and mostrecently,consideration of societalbehaviour.This has included
diversificationof water supply sourceswithin and outsideof Singapore;
cleaning-up of rivers and waterways;protection of water catchments;water con-
servation measures;developmentof infrastructure;wastewater treatmentand dis-
posal;production ofhigh-gradereclaimed waterfor potableand non-potable
purposes (known as NEWater); and desalination. The last two have been plan
supplementlocal catchmentand importedwater,and they haveeffectively
enhanced watersecurity (Parliamentof Singapore 2016a).All this is within a
regulatory and institutional framework that is modified and improved when a
required (Tortajada et al.2013).
The constraints of land area and competing land uses have added complex
water resources planning and implementation.The constantneed to increase pro-
vision of water due to population growth and economic and socialdevelopment
forcesnumeroustrade-offsbetweenland use (housing,commerce,industry,
defence, farming, fisheries, leisure activities, etc.) and water resources develo
In fact,land availability has been the main consideration when deciding on the
amount of land that can be converted into watersheds to collect water, and th
the size of the watersheds; the places where water and wastewater treatmen
as well as desalination plants,are built; which ones have to be built either under-
ground oron top of existing facilitiesin the mostinnovative ways;etc.This
balancing act continues until today (Ng 2018; Tortajada et al.2013).
Waterresources are strategic forSingapore.Johor,Malaysia,has historically
been an important source of water for the city-state, and about 50% of its wa
still imported from there.Severalwateragreements have been signed with this
purpose:in 1927 (no longer in force),1961,1962,and 1990.This paper will not
discuss the agreements or the related differences of opinion in differentperiods;
they have been discussed extensively elsewhere (e.g., Kog 2001; Long 2001;
et al.2002; Lee 2003,2005,2010; Ministry of Information,Communications and
the Arts 2003;NationalEconomic Action Council2003;Chang etal. 2005;Saw
and Kesavapany 2006;Sidhu 2006;Dhillon 2009;Shiraishi2009;Luan 2010;
Tortajada and Pobre 2011; Tortajada et al.2013).
Totalwaterdemand in Singapore is projected to double by 2060.Long-term
watersecurity strategiestowardsthis time horizon include continuing to aug-
menting supply from localsources and increasing the production capacities of
NEWaterand desalination.Already,two-thirds ofSingapore can be considered
water catchment areas where stormwater is collected.
86 C. Tortajada and C.Wong
[e-mail]

There are plans to increase this proportion to 90%.Regarding NEWaterand
desalination,PUB (Singapore’sNationalWaterAgency)plansto double their
production capacities by 2030. By 2060, the two sources are expected to sup
to 85% of Singapore’s water requirements. This water portfolio will be decisiv
ensure thatwateris available forall usesand also to reduce vulnerability to
climate-related uncertainties (Parliament of Singapore 2016b). Figure 4.1 is a
of Singapore,its water resources and also the water sales figures in 2016.
Climate change is likely to add constraintsin terms ofwatersecurity,and
Singapore is already planning forit. Extreme weatherevents,including heavy
rainfall and prolonged dry periods, are projected to occur more frequently, no
in Singapore but across Southeast Asia (Chow 2017). This has been a concern
Singapore for severaldecades.To develop unconventionalsources of water (re-
cycled wastewater and desalination) thatdo notdepend on climate,major invest-
mentswere madein the 1970sin researchand developmentto support
technologicaldevelopments such as membrane technology and reverse osmosi
The construction ofthe Marina Reservoir,the mosturbanised reservoiron the
island, for drinking purposes and flood control, was conceived in the same de
Four decades on,all these initiatives have been realised (Parliamentof Singapore
2010).
In 2014,Singapore experienced a two-month drought,the worstin many dec-
ades.February 2014 was the driestmonth since 1869,with near-zero rainfall.In
Fig. 4.1 Map of Singapore’s waterresources and watersales figures Source Buurman etal.
(Forthcoming)
4 Quest for Water Security in Singapore 87
[e-mail]

neighbouring Malaysia,waterrationing was implemented in Johor(from where
Singapore imports water), Selangor, Negri Sembilan, Kuala Lumpur, and Putra
In Thailand,20 provinces were declared droughtdisaster areas.Butin Singapore
there was no rationing; in fact, water consumption increased by 5% (Parliame
Singapore 2017a). This has been taken as a sign that Singapore’s strategies a
the correct path. But even so, there have been comments that this drought p
an opportunity to implementwater conservation strategies (Salleh 2014) thatwas
not realised (Tortajada 2016).
Therefore,within a framework of watersecurity,planning and investmentin
waterresources ahead oftime have become even more relevant(Parliamentof
Singapore 2017c),as has the participation of the population and commercialand
industrial sectors in using water more efficiently. The more involved the econ
and social sectors are in water conservation, the more secure the city-state w
the longer term.
Singapore hasnot followed any specific paradigm thathasbeen prevalent
internationally at any time. On the contrary, given its specific characteristics,
searched for its own most appropriate alternatives, looking for solutions that
cost-efficientin the long-term.Prioritieshave changed with time:from water
availability to self-sufficiency,then to security and,finally,to resilience.This
analysis presents a historical review of the decision-making, policies and prac
thathave contributed to Singapore’swatersecurity.It discussessome ofthe
trade-offs that have been made at different times in terms of land use,energy,and
food to develop waterresources.In this land-constrained city-state,it has been
essential to use land as efficiently as possible and for as high-value uses as p
This explains many of the decisions taken.
The analysis extensively refers to discussions in the parliament. The object
to show that water security,trade-offs,and related decisions have been a constant
concern for the leadership.
4.2 Water Security: Development of Water,Energy,
and Food Resources in Land-Constrained Singapore
The interlinkages and interdependencies among the water, food, and energy
in land-constrained Singapore are not intuitive. While in general water is need
energy and food production,this is notthe case in the city-state,which imports
nearly 100% of its energy,90% of its food,and 50% of its water resources.This
means thatwater resources are notnecessary to produce energy and thatonly a
small percentage is used for local agriculture. On the other hand, energy is ne
to pump,treat,recycle,desalinate,and distribute clean water,especially for pro-
duction of NEWater and desalinated water. The development of the various se
and how they have affected each other when this has been the case, are pres
the following sections.
88 C. Tortajada and C.Wong
[e-mail]

4.2.1 Development of Water and Energy Resources
The limited land in Singapore means that any land that is available has to be
the bestand mostproductive possible uses.To make sure thatSingapore would
have the necessary land for development,it introduced the Land Acquisition Act
(Parliament of Singapore 1966b). The act gave the government the power to
land for public development. The impacts of this act have been much discuss
terms of development, because the demand for land was high and escalating
increasing and competing uses, control of land prices was necessary to ensur
the cost of public projects could be met, including those related to water reso
At the time of independence in 1965,there were three reservoirs:MacRitchie
(formerly Thomson Road Reservoir),Lower Seletar,and Lower Peirce.However,
population growth in both urban and ruralareas,along with industrialisation,
resulted in higher demand for water and electricity.
To develop localcapacity for water resources,severalprojects and reservoirs
were built in the 1960s and 1970s. These include the Jurong Industrial waterw
expansion ofUpperSeletarReservoir,Kranji-Pandan scheme,ChestnutAvenue
waterworks,and Murai,Pandan,Poyan,Pulau Tekong,Sarimbun,and Tengeh
Reservoirs (Tsang and Perera 2011).Regarding electricity,Phase Iof the Pasir
Panjang Power Station was completed in 1965, adding 120 megawatts of gen
capacity (Parliamentof Singapore 1965).The added energy also supported the
government’s ongoing RuralElectrification Scheme,which broughtelectricity to
155 kampongs (villages) (Parliament of Singapore 1965).
Two pump houseswerebuilt in Pontian and Tebrau,in Johor, Malaysia
(Mohamad 2015).Approximately atthe same time,a booster station was builtto
increase the pumping capacity of MacRitchie Reservoir (Parliamentof Singapore
1965).
The average water consumption of 32 million gallons per day (MGD) in 194
had increased to over 80 MGD by 1965 (Parliament of Singapore 1965). In Au
1969,SeletarReservoiropened (Parliamentof Singapore 1970).It impounded
water not only from its own catchment, a protected area where development
been allowedhistorically,but also from eight neighbouringstreams:the
Sembawang,Sembawang Kechil,Simpang Kiri,BukitMandai,Mandai,Mandai
Kechil, Pang Sua, and Peng Siang. Water from these streams had to be pump
the reservoir because alleightwere atlower elevations (Parliamentof Singapore
1970).
Energy was increasingly needed forsewage pumping stations and treatment
plants (Parliamentof Singapore 1966a).This resulted in the construction ofa
sewage pumping house in Ulu Pandan (Parliamentof Singapore 1967b).The
government had the long-term objective to provide sewerage services to the
island,including urban and ruralareas,to preventwater resources being polluted
with sewage.However,given the limited human and financialresources,the
developmentof the sewerage scheme was carried outin phases and according to
priorities. For example, the developed areas of Toa Payoh, Jurong, Kallang Ba
4 Quest for Water Security in Singapore 89
[e-mail]

and other similar big new towns,where new projects were already taking place,
were given highest priority so that facilities would be ready in time for popula
when they moved to the new housing (Parliament of Singapore 1967a).
The sewerage system was continuously expanded,and by 1969 itserved over
half the population, a significant increase from a quarter of the population in
(Parliament of Singapore 1969).
To serve industrialdevelopment,more power stations were built.The power
station in Jurong was built to provide electricity for the Jurong Industrial Comp
westof the island.Stage I of the Jurong Power Station was completed in March
1971, with a generating capacity of 120 megawatts. With the increasing dem
power for both housing and industry,construction of Stage II had to startimme-
diately after (Parliament of Singapore 1971). In mid-1974, Stage II was compl
and three more 120 MW units were commissioned (Parliament of Singapore 1
This was followed by the building of the Senoko Power Station, completed in 1
(Senoko 1976).
As generating capacity expanded,substantial investments were made to extend
the networkfor transmissionand distribution,includingto the rural areas
(Parliament of Singapore 1966c). In the third quarter of 1974, PUB’s 10-year r
electrificationprogramme(EnergyMarketAuthority2017a)was completed.
Through this programme,electricity was provided to ruralareas and newly built
public housing (Energy MarketAuthority 2017b).It included approximately 500
projects in 18 stages of implementation. Electricity was now available to all p
the island,exceptremote ruralsites earmarked for redevelopment(Parliamentof
Singapore 1975). A 230 kV underground transmission network was constructe
transmit power from Senoko Power Station to load centres on the island (Sen
1976).
As industrialised and populated land area expanded,more energy was required
for water treatment.Water from the Pandan Reservoir initially flowed through an
industrialised and populated area and was prone to pollution.To make itsafe for
humanconsumption,the water had to undergomore advancedtreatment
(Parliamentof Singapore 1976b).A wastewatertreatmentplantwasalso con-
structed to treatthe liquid effluents of the petrochemicalcomplex in Pulau Ayer
Merbau.
In 1977, the Ministry of Environment conducted a survey to identify all sour
of pollution affecting rivers and water catchments.The main sources of pollution
were found to be pigs and ducks,trade and backyard industries,rundown urban
areas,squatter pockets,streethawkers,and riverine activities.A programme was
developed to coordinate the efforts of the ministries to eliminate such pollutio
Togetherwith a clean-up programme,premises would be connected to sewers,
reducing the numberof premises served by over-hanging latrines and nightsoil
buckets.These were phased out by 1987 (Tan et al.2008).
In rural areas where houses were not due for clearance within the next two
population had to install their own onsite wastewater treatment systems to tr
wastewater(Parliamentof Singapore 1982b).Streethawkers (food sellers)were
relocated to proper markets and food centres with treatment facilities. All but
90 C. Tortajada and C.Wong
[e-mail]

the pig farms in the Kallang Rivercatchmentwere relocated.Later,they were
phased out or encouraged to change to a different activity. The overall object
to prevent pollution of the reservoirs (Parliament of Singapore 1982b).
To this end, in 1981, a comprehensive plan was issued to clean up the Sing
River,Kallang Basin,and water catchments by 1987 (Tan etal. 2008;Tortajada
etal. 2013;Joshietal. 2012a,b). This enormous effortwas carried outtogether
with the redevelopment of Singapore.
Until the 1990s,Singapore’s power stations relied entirely on imported oilto
generate electricity (Parliament of Singapore 1981). In response to the oil cris
1973 and 1979, which affected the world economy, the government came up
policy to tap alternative sources of energy (Parliament of Singapore 1982a). P
stations were modified so that they could use different types and grades of fu
(Parliament of Singapore 1981). In addition, an 80 MW gas turbine was constr
atthe Pasir Panjang Power Station to supplementthe power supply during peak
hours and emergencies (Parliament of Singapore 1981). PUB (then responsibl
water, gas, and electricity; now the National Water Agency) converted five bo
at Senoko PowerStation to burn gas ratherthan oil(Parliamentof Singapore
1990a).Its 250 MW boilers were modified to use both naturalgas and fueloil
(Senoko 2014).
Between 1982 and 1984,the demand for water rose atan increasing rate:in
1982,by 3.5%;in 1983,by 5.1%;and in 1984,by 7.2%.Discussions in the
Parliament(Parliamentof Singapore 1985b)noted thatif Singapore continued
consuming water at the current rate, in 15 years, it would need more water th
available in all the reservoirs in Singapore, in addition to the water imported f
Johor.
The developmentof morereservoirsand projectsfollowed.The Western
Catchment scheme and Choa Chu Kong waterworks were completed in 1981,
Sungei Seletar, Bedok Scheme, and Bedok waterworks in 1986. Since at that
almost half of Singapore was a catchment area from where rainwater was col
(Parliamentof Singapore 1985a),PUB started looking to develop furtherwater
resources outside the island. It developed three schemes in Johor to draw the
resources Singapore was entitled to:the extension to the Scudaiwaterworks,the
extension to the Johorwaterworks,and the JohorRiverpipeline (Parliamentof
Singapore 1985a). Singapore recognised that the scope for further developm
surface waterresources was seriously constrained.If the rapid growth in con-
sumption continued,more expensive solutions,such as desalination,would be
necessary. Desalinated water was calculated to be more than 10 times as exp
as water from the local catchments (Parliament of Singapore 1985a,1986).
In 1990, Singapore and Malaysia signed a new water agreement as a suppl
to the 1962 Johor River agreement. The new agreement allowed Singapore to
a dam across SungeiLinggiu (a tributary ofthe JohorRiver)to facilitate the
extraction of water from the Johor River (Parliamentof Singapore 1989,1990b).
During negotiations between the two countries,it was also agreed thatMalaysia
would supply Singapore with gas on a long-term basis (Parliamentof Singapore
1989).
4 Quest for Water Security in Singapore 91
[e-mail]

Also in 1990,to furtherdiversify watersources,Singapore signed a water
agreementwith Indonesia on ‘economic cooperation in the framework ofthe
development of the Riau Province’. Under this agreement, Singapore and Ind
agreed to cooperate on the sourcing, supply, and distribution of water to Sing
The agreementalso included cooperation over trade,tourism,investment,infras-
tructuraland spatialdevelopment,industry,capital,and banking (Government
Gazette 1990).The wateragreementprovided forthe supply of1000 MGD for
100 years from sources in the Province of Riau. The sources would be harness
the appropriatetime afterevaluatingvariousoptions,includingdesalination
(Parliament of Singapore 1998b). This water agreement was not implemented
now only of historical interest.
In 1995,the power industry was restructured to increase efficiency and com
petition in both electricity generation and supply,starting with the corporatisation
of the Electricity and Gas Departments of PUB to form Singapore Power Ltd.To
facilitate competition, Singapore Power was structured as a holding companyfive separatesubsidiaries:two generationcompanies(PowerSenokoand
PowerSeraya),a transmission and distribution company (PowerGrid),a supply
company (Power Supply),and a piped-gas company (PowerGas).Another power
station being builtin Tuas was putunder a separate company,Tuas Power Ltd,
owned directly by Temasek Holdings,so thatit could competeagainstthe
Singapore Power generation companies. To facilitate competition in the gene
and supply sectors,the Singapore Electricity Pool was established as an exchange
for trading electricity. In March 1999, the government decided that the next s
restructuring the electricity industry was forSingapore Powerto fully divestits
generating companies to Temasek Holdings in 2001.This separated ownership of
the generators from the transmission and distribution network. In 2001, there
severalcompetinggenerationcompanies:PowerSenoko,PowerSeraya,Tuas
Power,and SembCorp Cogen.
The governmentcontinued looking foradditionallocalwatersources.With
experts’ support,PUB carried outgeophysical and hydrogeologicalinvestigations
of groundwaterresources.None were found,even atrelatively greatdepths.
Therefore,PUB focused on unconventionalsources ofwater:desalination,and
sources of non-potable water to supplement mainly non-potable uses (Parliam
Singapore 1998a). In 2002, after years of investment in research and develop
NEWater was introduced with the firstplantin Bedok.It was used for industries
which required large quantities of high-grade water, such as wafer fabrication
(Parliamentof Singapore2001a).In September2005,PUB also introduced
desalinated water,as its costhad reached an affordable level(Parliamentof
Singapore 2003a); the first plant was established in Tuas.
NEWaterand desalinationare energy-intensiveprocesses,raisingenergy
demand (Parliament of Singapore 2003a). Energy is necessary to treat and pr
freshwater, to pump it to the reservoirs, and later on to distribute it. NEWater
clean,and blending itwith reservoir water is notnecessary.It also requires more
energy.However,Singaporehas implementedthis practicefollowing the
92 C. Tortajada and C.Wong
[e-mail]

recommendations ofan internationalpanelof experts (Parliamentof Singapore
2003a,b). NEWater is less energy-intensive and cheaper to produce than desal
nated water.Therefore,it has been produced in largeramounts.Each of the
NEWaterplants has a separate reticulation system to distribute the waterto the
industrialestates and commercialareas where itis used (Parliamentof Singapore
2003a, b). NEWater has become one of the main sources of water for the city
(PUB n.d.).
Information on the energy used for allwater-related activities is notpublicly
available. However, we have compiled data from several sources on the amou
electricity supplied in the system between 1963 and 2016.It is presented in
Table 4.1.According to SingaporePower(SP) between 1995 and 2002 this
includes energy generated from powerstations and waste-to-energy incineration
plantsfrom thethen Ministry ofEnvironment(ENV) now Ministry of the
Environmentand WaterResources(MEWR). From 1995 to March 1998,the
electricity generated data was made up ofgeneration from powerstations plus
purchase from ENV (energy sentoutto grid).Due to the formation of Singapore
Electricity Pool (SEP) in Apr 1998, the purchase from ENV data has since chan
to generation from ENV.With the introduction ofautoproducers in 2000,the
generation data also includes generation from autoproducers (personalcorrespon-
dence with Singapore Power,November2017).According to Energy Market
Authority (EMA),2003 onwards,the data includes electricity from power station
and waste-to-energy plants (WEP) (personal correspondence with EMA, Novem
2017).
In terms of fuel, according to the Energy Market Authority (2016), oil used
the predominantfuel.From 2001,it changed to naturalgas with which approxi-
mately 95% of electricity in Singapore used to be generated, most of it via pip
from Indonesia and Malaysia. A Liquefied Natural Gas terminal was opened in
2013 allowing the city-state to import from markets globally.In 2016,natural gas
accounted for95.2% offuel mix, same percentage since2014.Main Power
Producers represented 93.2% of total electricity generated, with the remainin
generated by autoproducers (Energy Market Authority 2017c).
4.2.2 Development of Water Resources and Food
Production
Efforts to keep the reservoirs clean have had an impacton Singapore’s food pro-
duction.Farming and pig-raising activities have been relocated in some cases a
phased out in others. In 1965, family farming was considered an essential ele
of food security (Chou 2015;Kai 2012/2013).There were 20,000 farms,using
approximately 25% of the land (145 km2), and producing 60% of the vegetables
that were consumed on the island.
4 Quest for Water Security in Singapore 93
[e-mail]

Table 4.1 Total units ofelectricity supplied in the system in Singapore,1963–2016 (based
primarily on PUB annual reports)
Year Total units of electricity supplied
in the system
Sources
1963 822,922,790 kWh Public Utilities Board Annual Report 1964
(p. 29)
1964 914,232,150 kWh 1. Public Utilities Board Annual Report 1964
(p. 29)
2. Public Utilities Board Annual Report 1965
(p. 31)
1965 1,047,583,900 kWh 1. Public Utilities Board Annual Report 1965
(p. 31)
2. Public Utilities Board Annual Report 1966
(p. 50)
1966 1,236,471,850 kWh 1. Public Utilities Board Annual Report 1966
(p. 50)
2. Public Utilities Board Annual Report 1967
(p. 32)
1967a 1,424,434,000 kWh (reference
1)
1,424,534,000 kWh (reference
2)
1. Public Utilities Board Annual Report 1967
(p. 32)
2. Public Utilities Board Annual Report 1968
(p. 24)
1968 1,639,449,100 kWh (reference
1)
1,639 million kWh (reference 2)
1. Public Utilities Board Annual Report 1968
(p. 24)
2. Public Utilities Board Annual Report 1969
(p. 18)
1969 1876 million kWh (reference 1)
1,876.1 million kWh (reference
2)
1. Public Utilities Board Annual Report 1969
(p. 18)
2. Public Utilities Board Annual Report 1970
(p. 17)
1970 2,205.2 million kWh (reference
1)
2,205,207,100 kWh (reference
2)
1. Public Utilities Board Annual Report 1970
(p. 17)
2. Public Utilities Board Annual Report 1971
(p. 16)
1971 2,585,272,000 kWh 1. Public Utilities Board Annual Report 1971
(p. 16)
2. Public Utilities Board Annual Report 1972
(p. 18)
1972 3,143,560,910 kWh 1. Public Utilities Board Annual Report 1972
(p. 18)
2. Public Utilities Board Annual Report 1973
(p. 19)
1973 3,719,368,250 kWh 1. Public Utilities Board Annual Report 1973
(p. 19)
2. Public Utilities Board Annual Report 1974
(p. 16)
1974 3,864,322,500 kWh 1. Public Utilities Board Annual Report 1974
(p. 16)
2. Public Utilities Board Annual Report 1975
(p. 22)
(continued)
94 C. Tortajada and C.Wong
[e-mail]

Table 4.1 (continued)
Year Total units of electricity supplied
in the system
Sources
1975 4,175,980,480 kWh (references
1 and 2)
4,175.7 GWh (reference 3)
1. Public Utilities Board Annual Report 1975
(p. 22)
2. Public Utilities Board Annual Report 1976
(p. 24)
3. Department of Statistics Singapore 2017b
1976 4,604,920,600 kWh (references
1 and 2)
4,604.9 GWh (reference 3)
1. Public Utilities Board Annual Report 1976
(p. 24)
2. Public Utilities Board Annual Report 1977
(p. 20)
3. Department of Statistics Singapore 2017
1977 5,114,681,650 kWh (reference
1)
5,114.68 million kWh(reference
2)
5,114.7 GWh (reference 3)
1. Public Utilities Board Annual Report 1977
(p. 20)
2. Public Utilities Board Annual Report 1978
(p. 30)
3. Department of Statistics Singapore 2017
1978 5,897.99 million kWh (reference
1)
5,897.9 GWh (reference 2)
1. Public Utilities Board Annual Report 1978
(p. 30)
2. Department of Statistics Singapore 2017
1979c 6483 million kWh (reference 1)
6483 million kWh(Adding the
values from references 2 and 3)
1. Public Utilities Board Annual Report 1979
(p. 22)
2. Public Utilities Board Annual Report 1979
(p. 23): 35.2 million kWh purchased from
Ministry of ENV
3. Department of Statistics Singapore 2017d
Electricity generated from power stations:
6,447.8 GWh
1980 6,967.2 million kWh (Adding
values from references 1 and 2)
6,967.7 million kWh (Adding
the values from references 2 and
3)
1. Public Utilities Board Annual Report 1980
(p. 29): 6940 million kWh generated from
power stations
2. Public Utilities Board Annual Report 1980
(p. 29): 27.2 million kWh purchased from
Ministry of ENV
3. Department of Statistics Singapore 2017
Electricity generated from power stations:
6,940.5 GWh
1981 7,462 million kWh (Adding the
values from references 1 and 2)
7,461.9 million kWh (Adding
the values from references 2 and
3)
1. Public Utilities Board Annual Report 1981
(p. 22): 7442 million kWh generated from
power stations
2. Public Utilities Board Annual Report 1981
(p. 22): 20 million kWh purchased from
Ministry of ENV
3. Department of Statistics Singapore 2017
Electricity generated from power stations:
7,441.9 GWh
(continued)
4 Quest for Water Security in Singapore 95
[e-mail]