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  • Investigating solutions for Cape Town to ensure water security

    until 2040.

    Prepared by Sekonyela Tieho (SKNTIE001)


    Professor Neil Armitage

    Submission date: 23 November 2015

  • i

    Plagiarism Declaration

    i) I know that plagiarism is wrong. Plagiarism is to use another’s work and to pretend that it

    is one’s own.

    ii) I have used the Harvard Convention for citation and referencing. Each significant

    contribution to and quotation in this report form the work or works of other people has

    been attributed and has been cited and referenced.

    iii) This report is my own work

    iv) I have not allowed and will not allow anyone to copy my work with the intension of passing

    it as his or her own work.

    Names Student number Signature

    Sekonyela Tieho SKNTIE001

  • ii


    I would like to express my thanks the follow the following people, without them the completion

    of this research projection would not have been possible. My sincerest gratitude to Professor Neil

    Armitage, for his supervision, assistance and guidance throughout the whole project. To Dr

    Kirsty Carden, for guidance and providing me with contacts of my interviewees. To Lloyd

    Fisher-Jeffers, for helping me to refine my draft and for giving his time when I needed the

    consultations. To Nina Viljoen and Colin Mabudiro from the City of Cape Town for agreeing to

    have interviews with me. To Barry Wood who directed me to Nina Viljoen. Finally, to Dr Kevin

    Winter who gave me his time to interview him.

  • iii


    The City of Cape Town is expecting to experience a shortage of water by 2021. This is due to a

    rapid increase in potable water demand as a result of, amongst others, population growth and

    rising standard of living. In addition, Cape Town’s annual yield from current water sources is

    expected to decrease due to the impact of climate change. Therefore, the City of Cape Town

    needs effective solutions to increase the current water supply and/or decrease the demand of

    potable water in order to prevent water shortage.

    The aim of this research was to investigate potential solutions that can be implemented by the

    City of Cape Town to prevent water deficits between 2015 and 2040. This was done by

    identifying interventions which have not yet been implemented to their full potential in Cape

    Town and quantifying the amount of water that can be saved or added to the system by further

    implementing those interventions.

    In this research, the adoption of water efficient devices (WED) in domestic sector and reduction

    of water losses were identified as the two interventions that have the most potential in reducing

    total demand of potable water in Cape Town. According to still et al. (2008), only 10% of the

    South African population is using water efficient devices, therefore, there is a high potential of

    saving a considerable amount of water through the use of these devices in Cape Town. The

    calculations of this research showed that about 20% of the total water demand could be saved

    annually if water WED could by adopted throughout Cape Town. The combined effects of water

    efficient and water loss reduction has a potential of reducing water demand by 22.8%. The

    implementation of these interventions will therefore postpone the occurrence of the predicted

    water shortage by 6 years from 2021 to 2027.

    The adoption of water efficient devices in domestic sector and reduction of water losses in Cape

    Town could not meet the goal of this research which was to ensure water security until 2040.

    Further interventions to decrease water demand could have been introduced, but climate change

    is causing a decrease in water quantity from current sources. Therefore, additional water sources

    that will increase the current water supply were investigated. After analysing all the potential the

    additional water sources which were reviewed in this research, seawater desalination, re-use of

    treated effluent and addition of more aquifers into the current system were considered to be the

    best solutions. These additional water sources will increase the current water supply by a total of

    259Mm3/annum to 658Mm3/annum which will postponed water shortage due to unrestricted high

    water requirement growth by 15 years from 2021 to 2036.

    Although Cape Town is considered as a water-stress region, the results of this research showed

    that there are still potential interventions that can be implemented by the City of Cape Town to

    prevent a water shortage until the year 2040. Furthermore, the projected water balance of Cape

    Town for the year 2040 showed that, the demand will be 81Mm3 lower than supply if the City of

    Cape Town can implement the suggested solutions in this research report. Therefore, the

    suggested solutions will ensure water security beyond the year 2040. In addition, the 2040 water

  • iv

    balance for Cape Town shows an improved water system which is more diversified as seawater,

    treated effluent, groundwater and surface water are used at one time. This will therefore shift a

    big dependence of water from surface water as it forms 98.5% of the City of Cape Town’s water

    supply. As result, surface water will not be exhausted quickly.

    Finally, this research project has successfully achieved its goal of searching for potential

    solutions to ensure water security in Cape Town until 2040. In addition, the results of this

    research can be improved or used as the basis for similar research in the future.

  • v

    Table of content

    Abstract iii

    Table of contents v

    List of Figures vii

    List of Tables viii

    1. Introduction 1-1

    1.1 Background 1-1

    1.2 Problem Statement 1-1

    1.3 Objectives of the project 1-2

    1.4 Research method 1-2

    1.5 Scope and limitations 1-3

    1.6 Plan of development 1-3

    2. Literature review 2-1

    2.1 Water scarcity in South Africa 2-1

    2.1.1 Sustainable urban water management 2-2

    2.2 Historical water demand in Cape Town 2-3

    2.3 Current situation of water 2-4

    2.3.1 Infrastructure leakage index 2-4

    2.3.2 Water Wastage 2-5

    2.3.3 Inefficient water use 2-7

    2.3.4 Water end use 2-9

    2.4 Water supply in Cape Town 2-10

    2.5 Water demand in Cape Town 2-11

    2.6 Future water requirements for the Cape Town 2-13

    2.7 General recommended solutions to water deficit 2-15

    2.8 User education and campaign initiatives 2-16

    2.9 Leak detection and repair 2-17

    2.10 Replacement of pipes 2-18

    2.11 Pressure management 2-19

    2.12 Water efficient devices 2-23

    2.13 Tariff increase 2-24

    2.14 Greywater harvest 2-25

    2.15 Rainwater harvesting 2-25

    2.16 Private boreholes/ wellpoints 2-26

    2.17 Groundwater 2-26

  • vi

    2.18 Desalination 2-28

    2.19 Treated effluent 2-28

    2.20 Surface water development 2-30

    3. Procedure for wed calculations 3-1

    4. Results and discussion 4-1

    4.1 The situation of the city of Cape Town’s water supply 4-2

    4.2 User education and campaign programs 4-4

    4.3 Results of water demand reduction 4-5

    4.4 Options for additional water supply 4-8

    4.5 Treat effluent 4-10

    4.6 Seawater desalination 4-10

    4.7 Groundwater 4-11

    4.8 Future projections of water demand 4-12

    4.9 Final results 4-13

    5. Conclusions and recommendations 5-1



  • vii

    List of Figures

    Figure 2-1: South African gap of water demand and supply 2-2

    Figure 1.2: Historical water demand of Cape Town 2-4

    Figure 1-3: Historical trend of Cape Town’s infrastructure leakage index 2-5

    Figure 1-4: International average water use per capita per day 2-7

    Figure 1-5: Historical average consumption per capita per day in Cape Town 2-8

    Figure 1-6: Household water use per end-use 2-10

    Figure 1-7: Cape Town's sources of fresh water 2-11

    Figure 1-8: Cape Town's sectoral water demand 2-12

    Figure 1-9: Cape Town's water use cycle 2-13

    Figure 1-10: Projected impacts of climate change on the available water supply 2-14

    Figure 1.1: Projections for potable water demand 2-15

    Figure 2-12: Example


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