Why Water Consumption Is Declining in Gothenburg: Factors and Future Strategies Exploring the driving forces behind decline in water consumption and suggest practical solutions Master’s thesis in Infrastructure and Environmental Engineering KOUSHIKK SUYAMBULINGAM RAJA DEPARTMENT OF ARCHITECTURE AND CIVIL ENGINEERING DIVISION OF WATER ENVIRONMENT TECHNOLOGY CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2025 www.chalmers.se MASTER’S THESIS ACEX30 Why Water Consumption Is Declining in Gothenburg: Factors and Future Strategies Exploring the driving forces behind decline in water consumption and suggest practical solutions Master’s Thesis in the Master’s Programme Infrastructure and Environmental Engineering KOUSHIKK SUYAMBULINGAM RAJA Department of Architecture and Civil Engineering Division of Water Environment Technology Examiner: Thomas Pettersson Supervisor: Jesper Knutsson CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 2025 I Why Water Consumption Is Declining in Gothenburg: Factors and Future Strategies Exploring the driving forces behind decline in water consumption and suggest practical solutions Master’s Thesis in the Master’s Programme Infrastructure and Environmental Engineering KOUSHIKK SUYAMBULINGAM RAJA © KOUSHIKK SUYAMBULINGAM RAJA, 2025 Examensarbete ACEX30 Institutionen för arkitektur och samhällsbyggnadsteknik Chalmers tekniska högskola, 2025 Department of Architecture and Civil Engineering Division of Division Name Chalmers University of Technology SE-412 96 Göteborg Sweden Telephone: + 46 (0)31-772 1000 Cover: Artwork featured in the web article For the Sake of Future Generations: Ideas for Water Conservation, written by Hala Kamala and published in Sharjah 24 on September 5, 2024. Department of Architecture and Civil Engineering Göteborg, Sweden, 2025 I Why Water Consumption Is Declining in Gothenburg: Factors and Future Strategies Exploring the driving forces behind decline in water consumption and suggest practical solutions Master’s Thesis in the Master’s Programme Infrastructure and Environmental Engineering KOUSHIKK SUYAMBULINGAM RAJA Department of Architecture and Civil Engineering Division of Division Name Chalmers University of Technology ABSTRACT In the past two decades, the residential per capita water consumption has declined from 178 litres per capita per day (lpcd) in 2006 to about 130 lpcd in 2023. This decreasing trend was accomplished without any enforced municipal policies or coercive measures, with its scientific reason unknown and open to speculation. This thesis investigates the key factors driving the declining trend in a growing urban area that can help in developing effective water saving strategies for other cities. A multi-method approach was employed, incorporating quantitative data from Kretslopp och Vatten, qualitative insights from local resident surveys, and technical evaluations of fixtures and home appliances. The study reveals that improvements in appliance efficiency, retrofitting of fixtures, and public awareness on water conservation have significantly contributed to the reduced water use. Further, the study also examines future strategies to reduce the consumption further by adopting modern technologies on water recirculation, behavioural shift, policy reforms and volume-based water taxing. The concept of 50L Home was achievable through combining these strategies. Ultimately, this study offers solutions for sustainable water management and underscores the importance of integrating technology, policy reform, infrastructure design, and consumer behaviour to achieve long-term water security and resilience in the face of climate change. Key words: water conservation, Gothenburg, sustainable urban water use, behavioural change, efficient appliances, 50L home CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 II Contents PREFACE V LIST OF ABBREVIATIONS VI LIST OF FIGURES VII LIST OF TABLES VIII 1 INTRODUCTION 1 1.1 Background 1 1.2 Aim and Research Questions 2 2 METHODOLOGY 4 2.1 Research Design 4 2.2 Data Collection 4 2.2.1 Quantitative Data 5 2.2.2 Qualitative Data 5 2.2.3 Technical Data 6 2.3 Additional Studies 7 2.4 Proposal for Future Strategies 7 3 RESULTS 9 3.1 Overview of Water Consumption Data 9 3.2 Temporal Dynamics and Influencing Factors 11 3.3 Conservation through Fixtures and Fittings 19 3.4 Evolution of Home Appliances 23 3.4.1 Evolution of Washing Machines 23 3.4.2 Evolution of Dishwashers 25 3.5 Enforcement of Regulatory Frameworks 26 3.6 Behaviour and Awareness 28 3.7 Future Strategies 29 3.7.1 Technological Innovation 29 3.7.2 Change in Behaviour 30 3.7.3 Policy Reform 30 3.7.4 Water Taxing Reform 31 4 DISCUSSION 32 4.1 Interpretation of the Results 32 4.2 Implications of Findings on Water Conservation Strategies 33 4.3 Water Budget for 50L Home 33 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 III 5 RECOMMENDATIONS 35 6 CONCLUSION 36 7 REFERENCES 37 APPENDIX A: DAILY PER CAPITA WATER CONSUMPTION 42 APPENDIX B: MONTHLY EATER CONSUMPTION DATA FROM BOSTADSBOLAGET 47 APPENDIX C: REGULATIONS AND CERTIFICATIONS IN REGARD TO WATER CONSERVATION 48 APPENDIX D: SURVEY QUESTIONNAIRE WITH RESPONSES 53 APPENDIX E: WATER CONSERVATION CAMPAIGN POSTER BY KRETSLOPP OCH VATTEN 80 APPENDIX F: COIMBATORE CITY PILOT PROJECT TARIFF SHEET 81 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 IV CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 V Preface Imagine a future where water is scarce. A future where every drop counts. For many parts of the world, that future is now. But in Gothenburg, something remarkable has happened—despite enormous source of freshwater availability and being an active urban area, water consumption has declined significantly over the past two decades, from 178 litres per person per day in 2006 to just 140 litres today. Understanding the reason behind this declining trend can be used to shape a more sustainable future. During the course of my studies in Infrastructure and Environmental Engineering at Chalmers University of Technology, I have been consistently inspired by the potential of integrating science and engineering to address complex environmental challenges. Gothenburg's encouraging trend in reduced water consumption has provided a unique case study allowing exploration of sustainable urban resources for both academic and real life scenarios. This work is particularly personal to me because it reflects a commitment to developing practicable solutions that ensure long-term water security and enhance the resilience of our communities in the face of climate change. I wish to express my sincere gratitude to my supervisor, Jesper Knutsson, whose continual guidance, expert insights, and unwavering support have profoundly shaped my research and thinking. I would also like to express my heartfelt gratitude to Birthe Riisnes, Alexander Centeno, Marius Stücheli, Tobias Svanberg, Markus Barkestedt, Visard Matias, Hariharan AT, Uchit Sangroula, and Olof Bergstedt for their support and contributions making this journey even more impactful. I am especially grateful to my family and friends, whose constant moral support and encouragement kept me motivated throughout this endeavour. Their unwavering belief in my work provided the emotional fuel that carried me through the challenges of this research. Finally, the outcome of this thesis gives a great contribution to the sustainable water management, and it is my hope that the strategies and insights it presents will inspire further research and policy reform aimed at securing a sustainable future. Göteborg June 2025 KOUSHIKK SUYAMBULINGAM RAJA CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 VI List of Abbreviations DWTP - Drinking Water Treatment Plant KoV - Kretslopp och Vatten HH - Household IMS - Individual Metering System IoT - Internet of Things EU - European Union IMD - Individual Metering Device AMR - Automated Meter Reading CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 VII List of Figures Figure 1.1 Location map of Gothenburg (Göteborg) 2 Figure 2.1 Classification of Types of Data Collection for Water Usage Analysis 4 Figure 3.1 Daily per capita water consumption in Gothenburg since 2004 11 Figure 3.2 Spatial distribution of zones by proximity to city centre 11 Figure 3.3 Comparison of average daily per capita water consumption between weekends and weekdays 13 Figure 3.4 Zone wise seasonal average daily per capita water consumption distribution 14 Figure 3.5 Yearly seasonal average rainfall distribution 14 Figure 3.6 Household water use representation 19 Figure 3.7 Timeline of regulatory frameworks and recommendations issued by government bodies 20 Figure 3.8 Comparison between total monthly water consumption between before and after retrofitting faucets in selected apartment complexes 22 Figure 3.9 Evolution of water consumption in semi-professional laundry machines since 2000 24 Figure 3.10 Evolution of water consumption in private laundry machines since 2015 24 Figure 3.11 Evolution of water consumption in dishwashers per cycle since 2005 25 Figure 3.12 Swedish Standard energy performance labels for sanitary tapware 27 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 VIII List of Tables Table 3.1 Data on water production, leakage, supply, population and per capita consumption 10 Table 3.2 Specification of the zones based on building types and location 11 Table 3.3 Year wise observed similar dips and spike among different zones with possible causes 14 Table 3.4 Zone wise observed similar dips and spike among each year with possible causes 16 Table 3.5 Average water consumption during weekends and weekdays 18 Table 3.6 Evolution of water consumption in l/cycle for washing machines launched since 2000 24 Table 3.7 Evolution of water consumption in l/cycle for dishwashers launched since 2005 25 Table 3.8 Overview of innovative water-saving technologies and their applications 29 Table 3.9 Estimated water savings through innovative technologies in 2023 and 2050 30 Table 4.1 Daily Water Use Comparison: Current vs Efficient vs 50L Home Model 34 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 1 1 Introduction 1.1 Background Water is the most vital element for all living organisms on earth and while it is abundantly available throughout the world, it is distributed unequally making the planet have diverse ecosystem. The accessibility of potable water for consumption largely depends on the spatiotemporal distribution of water sources and is being heavily affected by human-caused climate change along with minor natural factors (Konapala, Mishra, Wada, & Mann, 2020). Although Sweden is blessed with enormous quantities of fresh water, the country is using less than 2% of the entire renewable water source (Worldometer, n.d.) (Statista, 2024). Nevertheless, Sweden does experience challenges in continuous supply of water for the consumers. Though Sweden experiences temperate climate with recurring precipitation and snow, low groundwater levels and supply shortages during the warm season have become a growing problem (Barthel, et al., 2021). Furthermore, Sweden’s population is projected to increase by about 22% reaching an estimated 12.6 million in 2070 up from 10.4 million in 2020 (Statistics Sweden, 2021). This increase is attributed to both domestic population growth and an influx of immigrants , which will consequently increase the demand for water production. Sweden also confronts issues in treating water from lakes and rivers, which have become progressively contaminated over time (Naturvårdsverket, 2022), potentially necessitating a change in treatment method or possibly a shift in water intake location. Moreover, Sweden also experiences about 20% water loss due to leakages which further increases the challenges in water production and maintenance (Sweden Water Research, n.d.). Above all, 40% of the Swedish municipalities report that the existing water services cannot meet the future demand (WSP, 2020). The deficits in the potable water supply can be countered by substituting it with alternate sources, augmenting existing water supplies and/or conserving water (Moglia, Cook, & Tapsuwan, 2018). However, finding alternate sources of water and supplementing water supply can incur significant expenses, potentially increase the cost of water or even impacting the economy of the country. This makes water conservation the most sustainable ideal long-term approach. Notably, a city in Sweden, Gothenburg (Göteborg) has achieved remarkable reduction in water consumption, positioning itself as a model for conservation strategies. Recently, the Gothenburg city municipality’s public service agency – Kretslopp och Vatten (KoV) released a statement on their social media page stating that daily water consumption decreased from 178 litres per capita per day (lpcd) in 2006 to 140 lpcd in 2023 [LinkedIn post]. The location map of the city is shown in Figure 1.1. Interestingly, this extraordinary reduction was accomplished without any enforced municipal policies or coercive measures, with its scientific reason unknown and open to speculation. Identifying the key factors driving the water conservation in a growing urban area can help in developing effective water saving strategies. By highlighting the most impactful approaches, practical solutions can be suggested for policymakers, engineers, and everyday citizens who are willing to drive towards the path of water conservation and sustainability. Ultimately, a road map for achieving 50 lpcd can be formulated, not through restricting water consumption but by optimizing the needs paving the way for greater resilience to climate change, lower costs for households, and a blueprint for other cities to follow. https://www.linkedin.com/posts/kretsloppochvatten_vatten-dricksvatten-miljaem-activity-7227176744372322304-oUQz?utm_source=share&utm_medium=member_desktop&rcm=ACoAAB5zXeYBYeRs-HvTrZHjSSeKXuWhc-7Xlm8 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 2 Figure 1.1 Location map of Gothenburg (Göteborg) 1.2 Aim and Research Questions This thesis aims to discover the key factors driving this trend of reducing water consumption in Gothenburg by analysing historical data, conducting a survey, examining technological advancements & infrastructural improvements and comparing similar cities & scenarios. This thesis is not limited to understanding the past, it aims to shape the future by providing suggestions for effective water conservation. In order to get valuable outcome, the thesis will answer to the following overarching research questions: i. What are the primary factors contributing to the reduction in water consumption in Gothenburg over the past two decades? ii. How have changes in consumer behaviour patterns influenced water usage in Gothenburg? iii. What role have new technologies and infrastructure changes played in reducing water consumption? iv. How do demographic and socioeconomic factors correlate with changes in water consumption? v. What is the most effective water-saving strategies implemented in Gothenburg, and how can they be applied systematically to continue reducing consumption? CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 3 The methodology of addressing the above research questions is by collecting water consumption data from Kretslopp och Vatten and analysing it with need for water and how it is used over the period of time. This will be supplemented by exploring and examining potential factors contributing the observed decline in daily per capita water consumption, including improvements in fixtures, innovation in efficiency of home appliance, behavioural changes and implantation of water conservation policies and recommendations. A dive into both quantitative and qualitative data on water consumption will help identify the factors driving reduction in water consumption. More detail on methodology of this thesis is given in the next Chapter. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 4 2 Methodology 2.1 Research Design The proposed study aims to research the underlying factors contributing to the unexpected decline in water consumption in an urban area characterized by steady population growth and infrastructure development, using a multi-approach method. To achieve this, the thesis employs systematic data collection incorporating different perspectives including historical trends, socio-economic influences, policy interventions, and behavioural changes by engaging various stakeholders working for water conservation. Given the rarity of this phenomenon, especially in an urban area, the study aims to gather insights from the analysis of comprehensive quantitative, qualitative, technical and comparative data collection. Statistical interpretation and trend analysis are conducted to identify the possible factors influencing declined water consumption and are supported by extensive literature review. Additionally, the outcome of this research is used to develop a structured framework that can be applied for further declining the water consumption in Gothenburg City and sustainable water conservation in other urban regions globally. 2.2 Data Collection Figure 2.1 Classification of Types of Data Collection for Water Usage Analysis •Efficiency through Retrofing •Water Consumption in Appliances •Water Saving through Taxing •Survey Questionnaire •Water Consumption •Leakage •Population Quantitative Data Qualitative Data Technical Data Additional Data CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 5 2.2.1 Quantitative Data A collaboration with the municipal agency - Kretslopp och Vatten was involved, who are responsible for both the supply of potable water and discharge of sewage for the inhabitants in Gothenburg. The city receives its tap water from the Vänern Lake and Göta River which are treated by Alelyckan DWTP at Lärjeholm and Lackarebäck DWTP at south of Delsjömotet (Göteborgs Stad, n.d.). While the first water supply system of Gothenburg dates back two centuries ago, the Alelyckan and Lackarebäck DWTPs were constructed between 60 and 160 years ago (Pettersson, 1987). KoV operates these two DWTPs along with the extensive water network distributed across the city. Additionally, they are also tasked with maintaining water quality and planning for expansions to satisfy the future drinking water demands in the Gothenburg City. The total quantity of water production in Gothenburg was used to analyse the trends in water consumption. The thesis focuses solely on household water consumption; thus, the data was refined by the distribution of water usage among different types of consumers such as residential, industrial, and municipal. This data was then compared with population statistics from Statistics Sweden’s database. Based on the interactions with officials from KoV, roughly 99% of the population in Gothenburg has municipal water connections, so the data was adjusted accordingly. Leakage volumes were also subtracted from the total quantity of water production to enhance the accuracy of the analysis. Data collection was extended to high resolution data sets, including daily and hourly water consumption to gain deeper insights. To minimize bias, data was collected from three District Meter Areas (DMA) comprised of individual houses and another three DMAs representing apartment type residential area. This approach allowed to validate the consumption data for different house types, seasons and times of day. The graphs of the collected data are given in Appendix A. A hypothesis was also made stating that there is a rising trend in usage of public facilities, as more individuals are showering at the gym post-workout or at the office after biking to work. Hence, data on water consumption at such commercial complexes were sought to investigate whether the decline in residential water consumption was a mere shift to commercial areas. However, limitations were encountered as data specific to certain commercial locations as mentioned above could not be appropriately refined for analysis. 2.2.2 Qualitative Data The water consumption pattern in Gothenburg cannot be studied only through quantitative data as it does not reflect upon the psychological and behavioural aspects of a consumer. While quantitative data focuses on numerical metrics, qualitative data provides insights on consumer perspectives over water conservation. Collection and analysis of qualitative data aids in the exploration of behavioural tendencies, awareness level and inclinations towards water consumption which thereby influences the declining water consumption trend. The findings can help identify the demographic groups that require more awareness on water conservation and provide recommendations to policy makers for effective water conservation in households. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 6 A set of interview questions was framed to target inhabitants in Gothenburg to understand the water usage behaviour, perception, awareness and attitude towards water conservation. These questions were prepared using Google Forms in both Swedish and English and was circulated via social media platforms such as Facebook and LinkedIn and also through WhatsApp Messenger. The interview questions are given in Appendix D. The survey was carried out online for all the consumers who receive water from KoV. Efforts were made to gather responses from diverse groups, ensuring representation from different demographic profiles and avoid bias. Thematic analysis was conducted on the responses received from the survey interview responses to detect patterns and themes. Data was categorized based on demographic profiles, highlighting common behavioural tendencies related to water usage and sustainability consciousness. Further, the outcomes were triangulated with the available quantitative data and literature reviews to validate the responses and have a broader perspective on the declining water consumption trend in Gothenburg. Despite all the efforts taken to ensure a representative sample, this methodology also has its limitations. While the intention of the survey was to cover diverse sample, the responses might not reflect the entire consumer base receiving water from KoV. Additionally, the responses received might also include interviewees’ favourable answers rather than their actual behaviour which makes the collected responses influenced by social desirability bias. No personal information was taken from the respondents, and they were informed of this in order to obtain unbiased results and uphold ethical integrity. 2.2.3 Technical Data Household water consumption occurs both directly through fixtures for sanitary and kitchen purposes and indirectly through electronic appliances for washing clothes and dishes. Therefore, the efficiency of water consuming installations such as taps, faucets, flush tanks in toilets, laundry machines and dishwashers play a crucial role in determining the overall water consumption pattern. This study reviews the technical specification of various fixtures and appliances manufactured over different time periods, assessing the efficiency improvements in comparison with similar older installations. Additionally, in order to conserve water and reduce energy cost associated with consumption of hot water, Bostad Bolaget replaced all the faucets in their apartment with sustainable models. This transition aimed to reduce water consumption without requiring behavioural changes from the residents. Water consumption data from Bostad Bolaget provides direct evidence of reductions in water usage achieved through the installation of efficient faucets in their residential properties. This study evaluates the impact of this switch through the water consumption data. Furthermore, electronic appliances which consume water, such as laundry machines and dishwashers comes with technical specification sheets that contain essential details such as water consumption, sustainability ratings and efficiency metrics. Appliances with the same CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 7 operational capacity but manufactured at different periods of time since at least two decades ago are considered to track the evolution of water efficiency in such appliances. The technical data analysed in this study presents a holistic evaluation of water efficient technologies and infrastructure improvement over time. By integrating details from product specifications with real world water consumption data, this analysis highlights the technical advancements contributing to the ongoing decline in water consumption pattern in Gothenburg. This research also validates the effectiveness of sustainable technologies in reducing water consumption. 2.3 Additional Studies An additional study was conducted to assess the influence of individual metering system (IMS) on households to conserve water by implementing consumption-based water pricing rather than a fixed cost tariff for the water supply. A pilot project on advanced Internet of Things (IoT)- based smart water distribution system that was implemented in Cheran Nagar, Coimbatore Smart City, India was evaluated for this study. The system provided real-time monitoring of water usage in HH. Additionally, telescopic water pricing was levied to further encourage consumer awareness on the importance of water conservation efforts. This study aims to evaluate the behavioural changes in water consumption resulting from a unique pricing model based on actual water usage instead of a predetermined tariff. The key objective of implementing telescopic pricing was to incentivise water conservation by imposing higher water charges on excessive consumption. Following the implementation of IMS in the District Metered Area – Cheran Nagar, Coimbatore Corporation provided data on water consumption recorded in the DMA. A novel tariff system was introduced and facilitated through the digital initiative of the ‘ROPeS Coimbatore WSMM’ app for smart phones. This application enables real time synchronisation of water consumption data recorded through the IoT devices. The tariff structure operates on a prepaid basis making the households to pay a fixed monthly fee for a basic water allocation irrespective of actual usage. Consumers requiring additional water supply can purchase extra quantities through the app which are subjected to expensive rates to discourage excessive use of water. The methodology of implementation, tariff structure and percentage of water saved beyond the allocated quantity are discussed in Section 3.7.4, presenting IMS as a viable strategy for sustainable water management in Gothenburg City. This additional study explores the integration of technological advancements with behavioural economics to improve water conservation. 2.4 Proposal for Future Strategies A comprehensive methodological approach was adopted to develop feasible and effective strategies for water conservation in households, contributing to the practical implementation of the 50L home initiative in Gothenburg. The 50L home is a futuristic concept aimed at enabling a standard living experience with an average water consumption of 50 lpcd without compromising essential water usage. The methodology integrates the enhancement of key CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 8 factors identified earlier, the exploration of emerging technological innovations and the development of awareness-based initiatives. The insights are gathered from the methodologies adopted to identify key factors including behavioural changes and technological assessment. Additionally, a strategic framework was created to enhance awareness among the consumer and promote water conservation. The feasibility of these strategies was analysed by identifying potential limitations and providing mitigation measures to ensure effective implementation in Gothenburg City. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 9 3 Results 3.1 Overview of Water Consumption Data Increase in population have direct influence in the raising water demand. The population growth in Sweden is steadily increasing with a projected raise of about 370,000 in five years from 2025 (IMF, 2025). This trend is reflected in Gothenburg municipality which has a substantial expanding population growing from 462,756 in 2000 to 608,993 by the end of 2023 (SCB, 2025). Kretslopp och Vatten (KoV) is responsible for production and supply of potable water for the households in Gothenburg municipality. Comprehensive data on the quantity of water produced, lost due to leakage and consumed by different categories such as house, apartment, industry and general service are provided by KoV over a span of two decades, i.e. from 2004 to 2023. The per capita water consumption in lpcd was estimated using the household consumption figures relative to the population and is given in Table 3.1. A clear declining trend emerging from the per capita water consumption data over the past two decades can be observed from the Figure 3.1. The per capita daily average water consumption stood at 174.7 lpcd in 2004 which then steadily decreased to 131.9 lpcd by 2023. This represents 24.5% reduction in water consumption, suggesting an overall improvement in water usage efficiency and awareness on water conservation among residents. An anomaly occurred in this downward trend during the years 2020 and 2021, coinciding with the COVID-19 pandemic. The curfew imposed during the pandemic period resulted in lifestyle changes, which led to higher water consumption in the kitchen for cooking and dishwashing as most restaurants were closed, more personal hygiene activities like taking multiple longer showers and handwashing, as well as more laundry and housekeeping (Campos, et al., 2021; Özbaş, Güneysu, Özcan, & Öngen, 2022). However, the declining trend continued once the pandemic was over while the curfew was lifted and more people started going to their workplace, schools, universities and shopping venues. The total volume of water supplied for various categories of consumers were found to have a relative stability which varied between 43 to 45 Mm3. Similar stability can be observed in water production as well. Overall, the presented data in this section indicates that the inhabitants of Gothenburg municipality have made progress towards efficient water use in their residences. Although total water consumption in houses have slightly increased, it has significantly decreased in apartments, thereby allowing to allocate more water to be used by industries and general service. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 10 Table 3.1 Data on water production, leakage, supply, population and per capita consumption Year Total water production1 (Mm3) Lost due to leakage1 (Mm3) Total supplied1 (Mm3) Supplied to different categories in Gothenburg municipality1 (Mm3) Sold to other municipalities2 (Mm3) Population in Gothenburg3 (nos.) Yearly household consumption2 (Mm3) Daily consumption2 (l) Daily per capita consumption2 (lpcd) House Apartment Industry General service Total 2004 61.502 12.797 48.705 4.2 26.6 5.6 8.0 44.4 4.305 481564 30.8 84153005 174.7 2005 59.060 10.714 48.346 4.5 26.4 5.5 7.9 44.3 4.046 484942 30.9 84657534 174.6 2006 60.610 11.981 48.629 4.7 26.3 5.5 8.3 44.8 3.829 489866 31.0 84931507 173.4 2007 60.586 11.987 48.599 4.7 25.9 5.5 8.3 44.4 4.199 493575 30.6 83835616 169.9 2008 61.793 12.406 49.387 4.8 25.9 5.4 8.4 44.5 4.887 500274 30.7 83879781 167.7 2009 62.916 13.711 49.205 4.8 26.1 5.0 8.4 44.3 4.905 507330 30.9 84657534 166.9 2010 63.913 14.904 49.009 4.7 25.6 5.2 8.5 44.0 5.009 513751 30.3 83013699 161.6 2011 61.731 12.500 49.231 4.6 25.5 5.0 8.3 43.4 5.831 520396 30.1 82465753 158.5 2012 61.274 12.706 48.568 4.6 25.6 5.0 7.9 43.1 5.468 526089 30.2 82513661 156.8 2013 62.512 13.770 48.742 4.7 25.6 4.9 8.0 43.2 5.542 533271 30.3 83013699 155.7 2014 63.306 14.539 48.766 4.8 25.7 4.8 8.2 43.5 5.266 541203 30.5 83561644 154.4 2015 63.353 12.984 50.369 4.8 25.8 4.9 8.1 43.6 6.769 548190 30.6 83835616 152.9 2016 65.591 14.810 50.781 4.7 25.8 4.8 8.2 43.5 7.281 556640 30.5 83333333 149.7 2017 62.727 14.216 48.511 4.8 25.4 5.0 8.1 43.3 5.211 564039 30.2 82739726 146.7 2018 64.728 15.296 49.432 4.8 25.3 5.2 8.3 43.6 5.832 571868 30.1 82465753 144.2 2019 62.659 13.615 49.045 4.8 25.3 5.4 8.2 43.7 5.345 579281 30.1 82465753 142.4 2020 62.623 12.760 49.863 5.1 26.4 5.1 7.3 43.9 5.963 583387 31.5 86065574 147.5 2021 63.781 14.416 49.365 5.3 26.0 5.5 7.7 44.5 4.865 587549 31.3 85753425 146.0 2022 60.614 12.293 48.321 5.0 25.1 5.5 8.1 43.7 4.621 596841 30.1 82465753 138.2 2023 59.093 9.769 49.324 4.6 24.5 5.8 8.9 43.8 5.524 604616 29.1 79726027 131.9 Calculations: Sold to other municipalities = Total supplied – Total supplied only in Gothenburg municipality Yearly household consumption = Water supplied in houses + Water supplied in apartments Daily consumption = Yearly household consumption / No. of days in the particular year Daily per capita consumption = Daily consumption / Population in Gothenburg 1 Data from KoV 2 Calculated values 3 Data from Statistikmyndigheten CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 11 Figure 3.1 Daily per capita water consumption in Gothenburg since 2004 3.2 Temporal Dynamics and Influencing Factors An in-depth temporal analysis was conducted on the water consumption data provided by KoV of all the eight zones. The zones represent different residential building types and the proximity to the city centre which is present in Table 3.2 and shown in Figure 3.2. Four zones were typified by multi-family apartment buildings, while the remaining four encompassed single- family houses and townhouses. This distinction in residential typology has significant influence over water consumption due to different behaviour and needs (Bich-Ngoc & Teller, 2018). Table 3.2 Specification of the zones based on building types and location Zone Type of buildings Approx. location 1 Apartments and a few commercial South of city centre 2 Only Houses (Some are townhouses/row-houses) North-east, more peripheral. 3 Mostly apartments, a few houses and a few commercial West of city centre 4 Only houses West, more peripheral. 5 Houses and a few apartments North of city centre 6 Houses and a few apartments East of city centre 7 Apartments (at high density) and a few commercial West of city centre 8 Apartments and a large amount of commercial City centre Figure 3.2 Spatial distribution of zones by proximity to city centre 130 135 140 145 150 155 160 165 170 175 2 0 0 4 2 0 0 5 2 0 0 6 2 0 0 7 2 0 0 8 2 0 0 9 2 0 1 0 2 0 1 1 2 0 1 2 2 0 1 3 2 0 1 4 2 0 1 5 2 0 1 6 2 0 1 7 2 0 1 8 2 0 1 9 2 0 2 0 2 0 2 1 2 0 2 2 2 0 2 3 W at er C o n su m p ti o n ( lp cd ) Year CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 12 The data revealed consistent differences in average water consumption across housing types, with zones primarily consisting of apartments consuming more water than those containing houses. Conversely, water usage was substantially lower in high-density apartment complexes, which may be attributed to spatial constraints limiting water-intensive activities like gardening or swimming pool and the presence of efficient plumbing systems. Furthermore, the limited availability of space in these apartments often precludes the owenership of individual washing machines, necessitating the use of communal laundry facilities which contributes positively to overall water conservation. Additionally, the spatial limitations may also avoid having leisure amenities such as bathtubs, which typically require greater water volumes compared to showers. Specifically, any bathtub requires over 200 litres of water, whereas an inefficient shower with a flow rate of 8 l/min consumes 80 litres for a 10-minute-long shower. Moreover, high-density housing tends to accommodate a greater proportion of working professionals or smaller households, who may spend less time at home and subsequently exhibit lower water consumption. Together these factors likely contribute to an average water consumption less than 50 lpcd. However, a detailed analysis of water consumption for specific activities within these apartments is not feasible due to the confidentiality of location details of Zone 4. Notably, townhouses and row houses in Zone 2 recorded consumption levels comparatively higher than other zones containing houses which may be attributed to the fact that most detached houses are subject to individual metering, aging infrastructure, absence of modern water-saving fixtures and have obsolete and inefficient water consuming appliances. However, these interpretations are speculative due to the lack of detailed contextual information such as building age, exact geographic location or demographics of household. To examine long-term patterns, daily water usage figures were visualized across years for each zone and vice versa (Refer Appendix A). This facilitated the identification of recurrent anomalies, such as distinct consumption spikes and dips correlating with population dynamics. As given in Table 3.3 and Table 3.4, the dips in water consumption were observed during key holiday periods such as Easter, Midsummer, and Christmas, likely corresponding to temporary outward migration of the city residents to celebrate in their native towns. Similarly, events such as Melodifestivalen—a prominent national music competition—appeared to coincide with the dip in water consumption may have occurred potentially due to the exodus of attendees to Malmö, the host city. Conversely, localized events such as Göteborgsvarvet Marathon, Partille Cup, and West Pride Festival were associated with increased consumption, presumably due to heightened visitor influx and major urban activity. However, these associations remain unverified and given the absence of event-specific consumption tracking, these correlations should be further interpreted with caution. The household water consumption patterns vary significantly throughout the week, reflecting urban working routines (Refer Table 3.5 and Figure 3.3). Weekly usage analysis further emphasized structured behavioural patterns, with average weekday (Monday, Tuesday, Wednesday, Thursday and Friday) water consumption appeared typically lower than weekend (Saturdays and Sundays) consumption across most zones. This discrepancy reflects structured weekday routines characterized by work and school commitments leading to shorter showers and reduced in-home activities, while weekends are predominantly dedicated to domestic tasks such as cooking, cleaning, and laundry (Ioannou, Kofinas, Spyropoulou, & Laspidou, 2017; Flume, 2020). An outlier was observed in Zone 8, where weekday consumption surpassed CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 13 weekend levels, plausibly due to increased commercial activity during weekdays attracting greater foot traffic which is in accordance with the zone’s characteristics. Figure 3.3 Comparison of average daily per capita water consumption between weekends and weekdays Seasonal water consumption trends were also evaluated using astronomical seasonal demarcations: Spring (March 20 – June 20), Summer (June 21 – September 21), Autumn (September 22 – December 20), and Winter (December 21 – March 19) (Time and Date, n.d.). The average zone wise per capita water consumption data is shown in Figure 3.4. Winter recorded the highest average residential water consumption across most zones. This trend may be linked to behavioural shifts, including longer shower durations and possible reliance on supplementary water-based heating solutions, although the latter is uncommon in Gothenburg (Rathnayaka, et al., 2015; Smart City Sweden, n.d.). In general, water consumption is expected to be higher during summer season due to increased demand for frequent showering, irrigation and recreational activities like swimming and other water sports (Bergel, Szeląg, & Woyciechowska, 2017). However, Gothenburg's consistent year-round precipitation (Refer Figure 3.5), limited urban space for irrigation and the classification of public green space outside residential category significantly reduce water demand during summer. Only zones 2, 4, 5, and 6 which contain houses might potentially contribute to water usage for gardening purposes. The data on per capita daily water consumption obtained from KoV contains missing values, negative figures and highly fluctuating error data. These inconsistencies may have resulted from infrastructure maintenance, leakage or malfunctioning water meters. 0 20 40 60 80 100 120 140 160 180 200 1 2 3 4 5 6 7 8 A vg . w at er c o n su m p ti o n ( lp cd ) Zone Weekends Weekdays CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 14 Figure 3.4 Zone wise seasonal average daily per capita water consumption distribution Figure 3.5 Yearly seasonal average rainfall distribution (World Weather Online, n.d.) Table 3.3 Year wise observed similar dips and spike among different zones with possible causes Year Month Dates Water consumption Zone Possible cause 2020 Feb 15-03 (Mar) Spike 3 Sports holiday 2020 Feb 19-02 (Mar) Spike 7 2020 Sep 23-24 Dip 2 Unknown 2020 Sep 23-24 Dip 6 2020 Sep 23 Dip 7 2020 Oct 1 Dip 2 Unknown 2020 Oct 1 Dip 3 2020 Oct 1 Dip 6 2020 Oct 1 Dip 7 2021 Apr 21 Dip 3 Unknown 0 50 100 150 200 250 1 2 3 4 5 6 7 8 A ve ra ge w at er c o n su m p ti o n ( lp cd ) Zones Spring Summer Autumn Winter 0 5 10 15 20 25 30 35 40 2020 2021 2022 2023 2024 R ai n fa ll (m m ) Year Spring Summer Autumn Winter CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 15 Year Month Dates Water consumption Zone Possible cause 2021 Apr 21 Dip 6 2021 Jun 25-26 Dip 1 Midsummer 2021 Jun 25-26 Dip 2 2021 Jun 25-26 Dip 3 2021 Jun 25-26 Dip 6 2021 Jun 25-26 Dip 7 2022 Apr 16-17 Dip 1 Easter holiday 2022 Apr 16-17 Dip 2 2022 Apr 16-17 Dip 3 2022 Apr 16-17 Dip 6 2022 Apr 16-17 Dip 7 2022 Apr 16-17 Dip 8 2022 Jun 24-25 Dip 3 Midsummer 2022 Jun 24-25 Dip 7 2022 Jun 24-25 Dip 8 2022 Oct 12-13 Dip 2 Unknown 2022 Oct 12-13 Dip 3 2022 Oct 12-13 Dip 5 2022 Oct 12-13 Dip 6 2022 Dec 6 Dip 5 Unknown 2022 Dec 6 Dip 6 2022 Dec 24-25 Dip 3 Christmas Holiday 2022 Dec 24-25 Dip 7 2022 Dec 24-25 Dip 8 2023 Feb 11 Dip 3 Unknown 2023 Feb 10-11 Dip 5 2023 Feb 10-11 Dip 6 2023 Feb 10-11 Dip 7 2023 Feb 24 Dip 2 Melodifestivalen in Malmö 2023 Feb 24-25 Dip 3 2023 Feb 23-25 Dip 5 2023 Feb 23-25 Dip 6 2023 Feb 23-25 Dip 7 2023 Apr 07-09 Dip 3 Easter holiday 2023 Apr 07-09 Dip 7 2023 Apr 07-09 Dip 8 2023 Jun 11 Spike 1 Clandestino Festival & West Pride 2023 Jun 11 Spike 2 2023 Jun 11 Spike 3 2023 Jun 11 Spike 4 2023 Jun 11 Spike 5 2023 Jun 11 Spike 6 2023 Jun 23-24 Dip 1 Midsummer 2023 Jun 24 Dip 3 2023 Jun 23-24 Dip 7 2023 Aug 5 spike 3 Unknown 2023 Aug 7 spike 6 2023 Aug 27 spike 2 2023 Aug 27 spike 3 2023 Dec 10-11 spike 2 Unknown 2023 Dec 11 spike 6 2023 Dec 24-25 Dip 1 Christmas Holiday CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 16 Year Month Dates Water consumption Zone Possible cause 2023 Dec 24-25 Dip 3 2023 Dec 24-25 Dip 7 2023 Dec 24-25 Dip 8 2024 Mar 30-31 Dip 1 Easter holiday 2024 Mar 30-31 Dip 3 2024 Mar 30-31 Dip 7 2024 Mar 30-31 Dip 8 2024 May 26 Dip 1 Unknown 2024 May 24 Dip 2 2024 May 24 Dip 3 2024 May 22-24 Dip 5 2024 May 23-24 Dip 6 2024 May 23-24 Dip 7 2024 Jun 21-22 Dip 1 Midsummer 2024 Jun 21-22 Dip 2 2024 Jun 21-22 Dip 3 2024 Jun 21-22 Dip 7 2024 Jun 21-22 Dip 8 2024 July 2 Spike 1 Partille Cup 2024 July 2 Spike 8 2024 July 24-25 Dip 2 Unknown 2024 July 24-25 Dip 3 2024 July 25 Dip 5 2024 July 23-24 Dip 6 2024 July 23-24 Dip 7 2024 Dec 24-25 Dip 1 Christmas Holiday 2024 Dec 24-25 Dip 3 2024 Dec 25 Dip 6 2024 Dec 24-25 Dip 7 2024 Dec 24-25 Dip 8 Table 3.4 Zone wise observed similar dips and spike among each year with possible causes Year Month Dates Water consumption zone Remark 2021 Jun 25-26 dip 1 Midsummer 2022 Jun 24-25 dip 1 2023 Jun 23-24 dip 1 2024 Jun 21-22 dip 1 2021 Dec 24-26 dip 1 Christmas Holiday 2022 Dec 25-27 dip 1 2023 Dec 24-25 dip 1 2024 Dec 24-25 dip 1 2020 May 27-28 dip 2 Unknown 2024 May 24 dip 2 2020 Dec 24-26 dip 2 Christmas Holiday 2021 Dec 24-26 dip 2 2022 Dec 24-30 dip 2 2023 Dec 24-29 dip 2 2020 Apr 11 & 14 dip 3 Easter holiday 2021 Apr 03-04 dip 3 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 17 Year Month Dates Water consumption zone Remark 2022 Apr 16-17 dip 3 2023 Apr 07-09 dip 3 2024 Mar 30-31 dip 3 2020 Jun 19-20 dip 3 Midsummer 2021 Jun 25-26 dip 3 2022 Jun 24-25 dip 3 2023 Jun 24 dip 3 2024 Jun 21-22 dip 3 2020 Dec 24-26 dip 3 Christmas Holiday 2021 Dec 24-26 dip 3 2022 Dec 24-25 dip 3 2023 Dec 24-25 dip 3 2024 Dec 24-25 dip 3 2021 Apr 16-18 Spike 4 Unknown 2022 Apr 18 Spike 4 2023 Apr 16 & 22 Spike 4 2023 May 13-14 Spike 4 Göteborgsvarvet Marathon 2024 May 18-22 Spike 4 2021 Dec 25-30 dip 4 Christmas Holiday 2022 Dec 25-30 dip 4 2023 Dec 25-30 dip 4 2024 Dec 25-30 dip 4 2021 Feb 05-07 Spike 6 Unknown 2022 Feb 1 Spike 6 2023 Feb 10-11 Spike 6 2022 May 22-23 dip 6 Unknown 2023 May 23 dip 6 2024 May 23-24 dip 6 2023 Aug 7 Spike 6 Unknown 2024 Aug 5 Spike 6 2021 Apr 03-04 dip 7 Easter holiday 2022 Apr 16-17 dip 7 2023 Apr 07-09 dip 7 2024 Mar 30-31 dip 7 2021 Jun 25-26 dip 7 Midsummer 2022 Jun 24-25 dip 7 2023 Jun 23-24 dip 7 2024 Jun 21-22 dip 7 2022 Apr 16-17 dip 8 Easter holiday 2023 Apr 07-09 dip 8 2024 Mar 30-31 dip 8 2022 Jun 24-25 dip 8 Midsummer 2023 Jun 23-24 dip 8 2024 Jun 21-22 dip 8 2021 Dec 24-26 dip 8 Christmas Holiday 2022 Dec 24-25 dip 8 2023 Dec 24-25 dip 8 2024 Dec 24-25 dip 8 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 18 Table 3.5 Average water consumption during weekends and weekdays Zone Average water consumption (lpcd) Change Weekends Weekdays 1 184.91 175.66 5% 2 145.91 136.83 6% 3 137.88 131.29 5% 4 48.27 44.49 8% 5 90.05 83.15 8% 6 75.78 71.84 5% 7 76.47 73.24 4% 8 137.01 142.13 4% CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 19 3.3 Conservation through Fixtures and Fittings Household water consumption is generally distributed across a range of domestic activities, including personal hygiene (e.g., showering and handwashing), direct ingestion through food and drinks, toilet flushing, dishwashing, laundry, and other miscellaneous uses. The proportional breakdown of these categories is illustrated in Figure 3.6 (Segerström, 2022). As depicted in the figure, the majority of household water use is attributable to personal hygiene and toilet flushing, which together represent the most water-intensive activities within a typical residence. Figure 3.6 Household water use representation In Sweden, the municipalities provide potable water without constraints on volume or pricing structures, reflecting a historical context of abundant water resources. As governmental agencies have gradually recognized the necessity of water conservation, many government boards have implemented regulatory measures to restrict water flow rates in residential fixtures and fittings. The timeline of these regulatory frameworks along with other water conservation measures implemented so far by the Swedish government and European Union are illustrated in Figure 3.7. In response to such regulations, manufacturers have gradually transitioned more towards the production of water-efficient appliances and fittings, facilitating their adoption across households worldwide. Despite Sweden has a longstanding reputation as a forerunner in environmental sustainability and water conservation, there were no formal regulations governing water use efficiency such as maximum flush volumes or flow rates for faucets and shower heads until 2020. The Boverket's Building Regulations since 2014 requires a mandatory provision of 6 l/min flow rate in faucets but the latest EU Taxonomy Regulation have limited the flow rate to a maximum of 6 l/min 2021 which contradicts to each other and there is no amendment is the Swedish Regulations on flow rate. Following updates in European Union directives, current regulations stipulate that bathroom and kitchen faucets should not exceed a maximum flow rate of 6 litres per minute, showers are restricted to 8 litres per minute, and toilet flush capacity must comply with a maximum full flush volume of 6 litres and an average flush volume of 3.5 litres (European Commission, 2021). Notably, Swedish manufacturers such as Gustavsberg and FM 7% 11% 11% 21% 43% 7% Food and Drink Laundry Dishwashing Toilet Flushing Personal Hygiene Other CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 20 Mattsson proactively began incorporating water-saving technologies into their product designs prior to the enforcement of such mandates, thereby contributing to both water and energy conservation efforts (Gustavsberg, n.d.; FM Mattsson, n.d.). Figure 3.7 Timeline of regulatory frameworks and recommendations issued by government bodies CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 21 A practical illustration of the effectiveness of these interventions can be found in the case of BostadsBolaget, a housing company that undertook significant measures to reduce water consumption by replacing traditional fixtures with water efficient alternatives. Since 2020, the company has invested approximately 12.8 million SEK to retrofit 25 residential complexes in Gothenburg. Of these, 7 complexes were selected for detailed analysis due to the availability of comprehensive water usage data of at least 12 months before and after retrofitting. A comparative plot of monthly water consumption each before and after retrofitting with corresponding values for each month is shown in Figure 3.8. The water consumption data during this intervention are presented in Appendix B. The results indicate that the percentage reduction in annual water usage across the seven studied complexes ranged from 4.13% to 10.77%, with an average reduction of 7.58%. Out of 25 complexes, 22 showed a positive trend towards water conservation, with an average monthly reduction in consumption of 9.6%. These reductions translated into substantial financial savings, amounting to approximately 5.2 million SEK, which includes both water costs and the energy costs associated with heating hot water. A rough estimate calculation was carried out to showcase the potential water savings by switching to more water-efficient showers and faucets. On an average, individuals wash their hands two to four times daily (Merk, Kühlmann-Berenzon, Linde, & Nyrén, 2014), and takes about 28 to 31 seconds each time (Shi, et al., 2023). An additional 5 seconds is added to account for water wasted in adjustment to the desired temperature as Gothenburg experiences cold weather around the year. Considering a frequency of four handwashing instances a day and with a total duration of 30 + 5 seconds per instance, the daily water use for handwashing amounts to 140 seconds. The EU taxonomy's recommended maximum flow rate in a faucet is 6 l/min, which translates to approximately 14 litres of water used for handwashing each day. Similarly, for calculating water spent on showering, an assumption of shower duration of 8 minutes per day (inclusive of the initial water wastage in adjusting the temperature) and people are considered to shower daily. On using the EU-recommended maximum shower flow rate of 8 l/min, daily water consumption in showering is estimated to be 64 litres. With water- conserving faucets of 4 l/min flow rate and showers of 6 l/min flow rate, overall daily water consumption can be reduced to 57.3 litres from the original 78 litres, i.e., approximately 20 lpcd reduction. These savings were achieved without the need for direct behavioural interventions or awareness campaigns targeting residents. Instead, the mere replacement of conventional fixtures with water-efficient alternatives was sufficient to generate meaningful reductions in consumption. This underscores the potential of technological solutions to drive sustainability outcomes even in the absence of user-driven behavioural change. The broader implications of this initiative are evident in a citywide trend toward reduced residential water consumption in Gothenburg, establishing it as a key driver of the overall decline in water usage. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 22 Figure 3.8 Comparison between total monthly water consumption between before and after retrofitting faucets in selected apartment complexes CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 23 3.4 Evolution of Home Appliances As illustrated in Figure 3.6, laundry and dishwashing collectively account for approximately 21% of total household water consumption. 3.4.1 Evolution of Washing Machines Although communal laundry facilities remain prevalent in Sweden, the adoption of private washing machines began to accelerate in the early 1990s. This shift now encompasses around 46% of rental apartments across the country (Klint & Peters, 2021). The type of the washing machines used, whether private or semi-professional has a significant influence on water consumption. Private models generally use more water per load than the semi-professional machines typically found in communal laundry rooms which has a negative effect over the declining water consumption trend. Hower, the survey on attitude toward water conservation in Gothenburg proves that most people use communal laundry facility irrespective of the ownership the residence and they do not prefer to own a private machine (More details on Section 3.6 and Appendix D). Hence adoption towards private washing machines is assumed to be low in Gothenburg. On average, an individual is estimated to operate a washing machine approximately 1.3 times per week (Schmitz & Stamminger, 2014). This study aims to investigate the underlying factors that have contributed to the long-term reduction in water consumption by washing appliances. To do so, four semi-professional laundry machines produced by the same Swedish manufacturer, all launched after the year 2000 are examined. Technical specifications are provided in Table 3.6, and Figure 3.9 visualizes their respective water usage. The data clearly demonstrates an improvement in water efficiency, with total consumption per cycle declining by approximately 54% over the past two decades. In addition, since private washing machines are still used by some of the residences, their evolution since 2015 is compared as similar to the comparison of semi-professional laundry machines. Although water consumption per cycle was considerably higher five years ago, latest models operate at levels comparable to their semi-professional counterparts at present. Figure 3.10 illustrates the evolution of decline in water consumption per cycle in private washing machines since 2015. The selected models are all from the Electrolux brand, and have a load capacity of 7–8 kg which shows 49% reduction in water consumption over the past decade. It should also be noted that the selection of these machines is subject to data availability. The data presented in the graphs (Figure 3.9 and Figure 3.10) shows that the water consumption per cycle in both semi-professional and private machines is almost same, indicating less discrepancy. This outcome could be attributed to the selection private washing machine models which are most efficient. However, having a private machine allows the consumer to use it multiple times, even at half loads, resulting in consuming more water. Various models with differing efficiencies and specialized features were available on the market, which may influence the comparative analysis presented in this study. Notably, in a consultation with Marius Stücheli (Head of Advanced Development Northern – Electrolux Professional Group), it was noted that laundry machines manufactured in the late 20th century consumed around 150 litres per cycle which is a threefold increase compared to the water use of contemporary models. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 24 Table 3.6 Evolution of water consumption in l/cycle for washing machines launched since 2000 Brand Model No. Year launched Max load Hot water Cold water Total water consumption E le ct ro lu x P ro fe ss io n al W375H 2000 7.5 14 76 90 W475H 2007 8 4 64 68 W575H 2011 8 12 50 62 WH6-8C 2020 8 3 46 49 Source: Respective product specification manual Figure 3.9 Evolution of water consumption in semi-professional laundry machines since 2000 Figure 3.10 Evolution of water consumption in private laundry machines since 2015 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 25 3.4.2 Evolution of Dishwashers A parallel analysis was conducted on dishwashers, given their similar contribution to the overall household water consumption. Dishwashing is a routine domestic task, and using a dishwasher instead of manual washing has been shown to reduce water use by 50% to 80% (Richter, 2011). Sweden also holds the highest rate of household dishwasher ownership in Europe (Actual Market Research, 2023), underscoring the importance of these appliances in national consumption patterns. On an average the dishwasher is estimated to be operated at a frequency of 1.9 cycles per week per person (Alt, et al., 2023). To assess trends in water use, six dishwashers of the same size (60 cm wide), all manufactured by the same brand and launched between 2000 and 2025, were selected for comparison. Their specifications are given in Table 3.7, and the water consumption trends are illustrated in Figure 3.11. The findings reveal a substantial improvement in efficiency, with a 44% reduction in water use over the two- decade span, highlighting a critical technological driver behind the observed decline in residential water consumption in Gothenburg. Table 3.7 Evolution of water consumption in l/cycle for dishwashers launched since 2005 Brand Model No. Year launched Total water consumption E le ct ro lu x EDW5505EPS 2005 27.6 ESL64022 2008 25 ESL68500 2010 23 ESL5201LO 2015 17 ESL69200RO 2020 14.4 ESZ89400UX 2022 12.2 Source: Respective product specification manual Figure 3.11 Evolution of water consumption in dishwashers per cycle since 2005 CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 26 3.5 Enforcement of Regulatory Frameworks In the recent decades, Europe and particularly Sweden has demonstrated growing recognition among scientists and policy makers regarding the importance of sustainable water governance, leading to the development of new legislations and recommendations (Dawson, Persson, Balfors, Mörtberg, & Jarsjö, 2018). The list of existing Swedish regulations, standards, European Union (EU) directives and green building certifications relevant to household water consumption is provided below, and the corresponding legal clauses are detailed in Appendix C. The timeline of these regulatory frameworks implemented by the Swedish government and European Union are illustrated in Figure 3.7. Legislation/Certifications Scale of effect Interest of implementation Reference Planning and Building Act (SFS 2010:900) Sweden Mandatory (Ministry of Rural Affairs and Infrastructure, 2010) Boverket´s mandatory provisions and general recommendations (BFS 2011:6) Sweden Mandatory (Boverket´s Building Regulations, 2011) Method for determination of energy efficiency of mechanical basin and sink mixing valves – Single lever mixer (SS 820000:2020 Sanitary tapware) Sweden Voluntary (Swedish Standard, 2020) Sanitary tapware - Method for determination of energy efficiency of thermostatic mixing valves with shower (SS 820001:2010 Sanitary tapware) Sweden Voluntary (Swedish Standard, 2010) EU Water framework Directive (2000/60/EC) Europe Mandatory (European Union, 2000) EU Taxonomy Regulations (Only regulation on limiting flow rate and consumption volume of various products) Europe Mandatory (European Commission, 2021) Regulation on Eco-design requirements for household dishwashers (EU) 2019/2022 Europe Mandatory (European Union, 2019) Regulation on Eco-design requirements for household washing machines and washer- dryers (EU) 2019/2023 Europe Mandatory (European Union, 2019) LEED for Homes Global Voluntary (LEED, 2019) LEED for Building Design and Construction Global Voluntary (LEED, 2025) BREEAM International New Construction Global Voluntary (BREEAM, 2021) BREEAM In-Use International Global Voluntary (BREEAM, 2020) DGNB System – New buildings Global Voluntary (DGNB System, 2023) Although Sweden is often regarded as a leader in sustainability and resources conservation, its regulatory journey in water conservation measure began with the implementation of BFS 2011:6. This regulation mandated to design plumbing systems capable of detecting leaks, CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 27 marking a significant step towards sustainable water management. In contrast, broader legal instruments such as SFS 2010:900 provided only general statements regarding the need for water conservation. Since 2010, Swedish standards on various categories of sanitary tapware have been established, with a primary focus on enhancing energy efficiency. While adherence to these standards remains voluntary, they have been widely adopted by manufacturers like Gustavsberg and FM Mattsson aiming to obtain energy classification certifications. These labels, include information such as energy ratings and flow rate, serve as marketing tools to encourage consumer preference for environmentally friendly options (an example is presented in Figure 3.12). Figure 3.12 Swedish Standard energy performance labels for sanitary tapware Despite the absence of comprehensive national legislation mandating water conservation, Sweden is bound by the EU Water Framework Directive (2000/60/EC), which has been legally binding for all EU member states since its inception in 2000. This directive emphasizes sustainable water use, recover cost for water services and promotion of water-efficient technologies. In addition, the EU’s Taxonomy Regulations came into effect in 2021 have introduced requirements for limiting water flow rates in faucets to 6 l/min and showerheads to 8 l/min, toilets to have dual flush system with a maximum full flush volume of 6 litres and a half flush volume of 3.5 litres in all new buildings including residential. Further, EU has also set regulations for work plan on improving the efficiency of appliances such as washing machines and dishwashers to save 711 and 16 million m3 by 2030. Beyond statutory obligations, actors in real estate and construction sectors have increasingly sought to demonstrate environmental stewardship by voluntarily pursuing green building certifications. These certification schemes award points for the integration of water-saving features such as high-efficiency fixtures, water recycling, water metering, and mechanisms to detect and prevent leaks. Collectively, these regulatory and voluntary initiatives have played a pivotal role in fostering a societal shift toward water conservation, aligning environmental objectives with building practices and technological advancement. Notably, the cumulative impact of these frameworks has possibly been a key driver in the decline of per capita water consumption in Gothenburg. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 28 3.6 Behaviour and Awareness To assess public awareness, attitudes, and behaviours towards water conservation, a bilingual online questionnaire (available in both Swedish and English) was prepared to ensure accessibility for a diverse respondent base. The developed questionnaire was published primarily through social media platforms, particularly in Facebook groups with more than 10,000 members. Additionally, printed posters with QR codes were placed across the university campus to broaden outreach and improve participation. Despite being shared widely on online platforms, the response rate remained notably very low. To address this, a supplementary strategy was adopted involving direct engagement by solicitation of random strangers to fill out the survey form in a public setting. Although this approach increased the sample size, the ultimate number of responses yielded was only 44. The limited number of responses restricted the ability to conduct detailed demographic-based analyses. Nevertheless, the data was still analysed for obtaining insights regarding water use behaviour and awareness. A summary of the responses obtained is given below and the detailed responses are attached in Appendix D. Water Usage Behaviour • A substantial proportion of participants lack awareness on quantity of water consumed as no individual metering for water was present. • Despite the majority expressing an interest in water conservation, they still tend to take longer shower (≥6 min) contradicting their stated intentions. Furthermore, only 16% of the respondents reported having water efficient installations. • About 82% of the respondents relied on communal washing machines and does not prefer to buy personal machines. Notably, 64% were unaware of the age of the laundry machines while 20% reported using more than 10-year-old machines. • While only 43% of the respondents own a dishwasher, the remainder are not interested to buy such appliances. Among those with dishwashers, most are less than 10 years old. • Encouragingly, 86% of the respondents reported to have dual flush system in their toilets which is widely recognized for water conservation. Perceptions, Awareness & Attitudes • Over half of the respondents expressed their willingness to use sustainable faucets which has reduced flow rate. • Majority of the respondents supported water conservation with environmental concern being their primary motivator. • A very large share of respondents reported either rarely or never encountering public campaigns focused on water conservation. • When asked about the implementation of volume-based water taxation, 41% expressed support, whereas 25% opposed the idea. Despite the scope of this study is constrained by its modest sample size, the findings provide preliminary understanding of the disjunction between awareness and behaviour in water CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 29 conservation practices. While there is broad awareness of the importance of water conservation, the consistent implementation of conservation practices remains limited. The widespread use of communal washing machines and the prevalence of dual-flush toilets indicate that passive water conservation is taking place, despite inconsistencies in proactive behavioural change. These insights highlight the need for educational initiatives and policy measures to bridge the gap between awareness and sustainable actions. 3.7 Future Strategies The transition towards sustainable water conservation practices requires a multi-faceted approach that does not solely rely on consumers. It requires the systematic integration of technological advancements, governance framework reforms, and behavioural influences (Dadvar, Mahapatra, & Forss, 2021). This section synthesises future-oriented strategies identified through literature review, online resources, and expert brainstorming 3.7.1 Technological Innovation Role of technological innovations in water conservation can effectively minimise wastewater and enhance sustainable water management (Sustainability Media Lab). While conventional methods such as the adoption of low-flow fixtures and water monitoring remain valuable, emerging technologies offer more sophisticated and effective mechanisms. The table below presents selected water recycling technologies suitable for small-scale domestic applications. Table 3.8 Overview of innovative water-saving technologies and their applications Innovative Product Application Source Orbital Shower Closed loop shower system thereby minimizes water loss. About 90% of shower water is saved. (Orbital, n.d.) Hydraloop Recycles water from showers, washing machines, hand basins and reuse it for gardens, toilets, laundry, and pool top-ups, reducing water usage by 25-45%. (Hydraloop, n.d.) Nubian Greywater Treatment Systems Treats greywater with its new age slimline treatment unit. (Nubian Water Systems, n.d.) Graytec Blue Circle System Uses advanced sensors to precisely identify and separate unusable water, ensuring only the cleanest, most reusable water is filtered and recirculated. (Graytec, n.d.) Vacuum toilets Decrease water usage for flushing and enable recovery of macronutrients such as phosphorus, nitrogen, potassium and sulphur which are used to manufacture fertilizers. (Smart City Sweden, n.d.) Mimbox Recycles water used in laundry. (Mimbly, n.d.) The implementation of such innovative technologies on decentralized greywater recycling systems and recirculating showers significantly reduces overall water consumption, thereby contributing to the 50-liter home when integrated with other water conservation measures. (50L Home & Arcadis, 2024). Despite the potential of such technologies, consumers may encounter resistance due to psychological discomfort associated with the reuse of water, particularly for showering (Kattenburg, 2021). Thus, use of recycled water for applications such as toilet flushing and irrigation are more socially acceptable. Additionally, the operational complexity and maintenance particularly with filter replacements pose practical challenges for many CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 30 consumers. Therefore, the design of user-friendly, automated maintenance features is crucial for household adoption (Orbital shower and Mimbox are some examples). A rough estimate of quantity of water saveable through the adoption of innovative water-saving technologies is presented in Table 3.9. The analysis is based on a daily per capita consumption of 131.9 lpcd for the year 2023 and projected daily per capita water consumption values derived using linear regression of ~73 lpcd for 2050. These projections reflect anticipated reductions due to behavioural and technological changes. The implementation of water-efficient systems such as recycling shower water, grey water reuse, and vacuum toilets demonstrates potential water savings ranging between 40% and 65% of total daily consumption. Specifically, on use of these technologies, the estimated quantity of water consumed ranges from 47 to 79 lpcd in 2023 and 35 to 44 litres in 2050, indicating a significant opportunity for water conservation through innovative domestic technologies. Table 3.9 Estimated water savings through innovative technologies in 2023 and 2050 Product Type Percentage of water saved (approx.) Quantity of water saved (litres) Description 2023 2050 Recycle shower 90% 58 23 8 min shower at 8 l/min is considered for 2023 while 5 min shower at 5 l/min is considered for 2050 due to positive behavioural changes Reuse grey water 30% 25 14 Residential grey water generation is estimated to be ~64% of total water consumption (Seifu, 2022) Vacuum toilet 100% 28 15 21% of water used for toilet flushing from Figure 3.6. Also average of 5 flushes per person is considered (DeOreo & Hodgins, 2016) Total water saved (litres) 53-85 29-38 Approx. 40-65% of water can be saved 3.7.2 Change in Behaviour As demonstrated by the survey results discussed in Section 3.6, there is a pressing need to enhance consumer awareness, particularly concerning water use during showering. The most common approach to make consumers more aware of water conservation and encouraging water saving behaviour is through knowledge transfer in the form of water conservation campaigns for instance (Salmon & Brouwer, 2025). Behavioural change remains one of the most cost-effective strategies for achieving water conservation. Last year KoV launched a campaign in Gothenburg encouraging residents to limit showers to three minutes, exemplified by campaign materials included in Appendix E (Vårt Göteborg, 2024). Additional behavioural interventions include integrating water conservation awareness into school education and employing behavioural nudges, such as ‘mock billing’ strategies, which simulate water costs to raise awareness without actual financial implications. 3.7.3 Policy Reform As explained in Section 3.5, there is currently a lack of robust legislation governing domestic water conservation in Sweden. Existing regulatory frameworks, such as the flow rate limits CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 31 stipulated by the EU Taxonomy Regulations, are outdated, and many modern fixtures are already much better than these efficiency standards. To stimulate greater progress, policy reforms may include: • Lowering the permissible flow rates for domestic water fixtures (faucets and showerheads). • Mandating the integration of water-saving technologies in new residential developments. • Providing fiscal incentives or subsidies for manufacturers and consumers adopting water-efficient innovations. Such legislative initiatives can be enforced for progressive water conservation in households. 3.7.4 Water Taxing Reform Article 9 of the EU Water framework Directive (2000/60/EC) obliges member states to adopt water-pricing policies to use water resources efficiently, and thereby contribute to the environmental objectives. In Sweden, however, the cost charged to consumers for their water use is set below the marginal cost of providing water leading to municipalities underinvesting in the water infrastructures (Westling, Stromberg, & Swain, 2020). Volumetric fees fail to reflect actual household consumption, as individual metering devices (IMDs) are rare in Gothenburg and KoV imposes a fixed charge. As a result, a fixed fee for water consumption is measured from 14.55 SEK/m3 for an assumed usage of 100 m3/year for small houses and 1500 m3/year for other properties (Kretslopp och vatten, 2025). Based on the pricing, a small house in Gothenburg City pays 1455 SEK for about 274 l/day/HH whereas about 54% of the Swedish HH have more than 1 person which means 137 lpcd for a 2 person HH, 91 lpcd for a 3 person HH and so on, thereby charging so low. The volumetric fee was considered to be low even for the household with particularly small economical means (Köhler, 2017). Moreover, there are also statements against introducing volumetric billing in Sweden by many citizens, especially due to inequal billing and making it unfair for people that are already struggling (Mangold, Morrison, Harder, Hagbert, & Rauch, 2014). To counter this, a potentially equitable solution can be found in the telescopic pricing model piloted in Coimbatore Smart City, India. Under this system, a base allocation calculated from census data (e.g., 135 lpcd base allocation x no. of person in that HH x 30 days → monthly allocated quantity) is provided at a subsidised rate. Consumption beyond this allocation incurs exponentially increasing charges. This model has successfully incentivised water conservation without penalising basic needs. Its effectiveness was further enhanced through the deployment of IoT-enabled smart meters and Automated Meter Reading (AMR) systems, which provide real-time consumption data and enforce usage limits through prepaid mechanisms. Details of the tariff structure are included in Appendix F. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 32 4 Discussion 4.1 Interpretation of the Results The primary objective of this study was to identify and analyse the key factors contributing to the declining per capita household water consumption trend in Gothenburg, Sweden, despite a growing population and stable water production levels. Though this population should raise concerns over managing water resources, the data states otherwise. The findings from the study, triangulated across quantitative data, technological insights, regulatory frameworks, and behavioural assessments, provided a comprehensive understanding of this trend. RQ1: Primary Factors Contributing to Declining Water Consumption The results highlight the wide spread adaptation of technological advancements, as the consumers increasingly integrate water efficient fixtures and appliances. This shift played a key role in contributing to the declining trend, confirmed by reduction in residential water usage following the retrofitting of modern water efficient faucets as well as significant drops in water consumption by advancement of washing machines and dishwashers. Another key driver, such as the enforcement of regulatory policies, has also played a role in influencing manufacturers to design more sustainable products thereby reducing the water consumption. RQ2: Influence of Consumer Behaviour The survey responses revealed a gap between awareness and consistent practice. While most residents expressed their willingness to conserve water, behaviours such as taking long showers persisted highly. However, the high adoption rates of dual-flush toilets and the use of communal washing machines reflect passive conservation behaviours driven by design rather than individual choices. RQ3: Role of New Technologies and Infrastructure Modern washing machines and dishwashers have achieved significant leaps in terms of water efficiency, saving 54% water in washing machines and 44% in dishwashers. Both these technological advancements, alongside water-efficient sanitary tapware, have substantially curbed the water use without necessitating behavioural change. RQ4: Demographic and Socioeconomic Correlations Although limited by sample size, the study suggests that apartments had higher per capita consumption than the detached houses, due to possibly differing infrastructure or communal habits. Variations by day and season, such as higher winter use and weekend spikes, further reflect consumption patterns tied to lifestyle in different type of residential buildings. RQ5: Effective Strategies and Systematic Applications Technological retrofits and voluntary corporate efforts towards sustainability emerged as the most effective, scalable strategies. The passive nature of such interventions assures uniform impact across the population irrespective of their demographic profiles. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 33 4.2 Implications of Findings on Water Conservation Strategies The implications of these findings are multifaceted and offer real-world guidance for sustainable urban water management: Technological Adoption is Crucial: The water reductions from fixture retrofits and appliance efficiency imply that citywide upgrades can serve as the backbone of future conservation initiative. Such renovation should be incentivized or subsidized with high priority. Regulation and Standards: While Sweden lacks stringent national regulations on water efficiency, adherence to EU directives and voluntary efforts by the manufacturers have been effective. Updating the maximum flow rates standard and policies favouring removal of inefficient appliances beyond projected lifespan can enhance impact. Behavioural Interventions Need Strengthening: Awareness campaigns, educational programs, and behavioural nudges (e.g., mock billing, real-time feedback) should complement technological efforts. The disconnect between stated concern and actual practices underlines the need for persistent and creative public engagement. Economic Tools Have Untapped Potential: Fixed tariffs currently in practice in Gothenburg, conceal the real cost of consumption and do not encourage water savings. The telescopic tariff system tested in Coimbatore presents a socially equitable and operationally feasible alternative, especially when paired with smart metering technologies. Urban Planning and Housing Design: Differences in water consumption across different housing types suggest that urban form impacts sustainability. Future developments should incorporate design elements that naturally limit high-consumption behaviours (e.g., compact spaces, efficient communal facilities). Policy Formulation for the 50L Goal: Achieving a 50 lpcd standard without compromising quality of life through a multi-faceted approach is an achievable target by combining technological advancements especially in recycling grey water, improved infrastructure, regulatory reforms, economic incentives, and awareness. The Gothenburg case proves this can be achieved without draconian measures. 4.3 Water Budget for 50L Home A calculation was performed from an optimistic perspective to emphasize the potential for maximum efficiency in water usage. This analysis aims to achieve the goal of reducing the current per capita water consumption to 50 lpcd through behavioural changes, adoption of high efficiency appliances and recycling of greywater. The anticipated reduction in personal behaviour is expected to be driven by awareness and water taxing with telescopic charges. The table below presents comparison of daily water use between current, efficient and 50L Home model. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 34 Table 4.1 Daily Water Use Comparison: Current vs Efficient vs 50L Home Model Common water uses Frequency Current estimate Efficient use Much efficient use (50L Home) Assumption Qty. Assumption Qty. Assumption Qty. Bath/shower Once per day 6 min by 7/min faucet 42.0 5 min by 6 l/min faucet 30.0 4 min by 6 l/min faucet 24.0 Toilet full flush Once per day 6 l tank 6.0 6 l tank 6.0 4 l tank 4.0 Toilet half flush 4 times per day 5.5 l tank 22.0 3.5 l tank 14.0 2 l tank 8.0 Hand wash 4 times per day 35 s per wash by 6 l/min faucet 14.0 - 14.0 4 l/min faucet 9.3 Dish washing 1.9 times per week No dishwasher 14.0 12.2 l water consumption per cycle 3.3 Maxed efficiency 3.3 Laundry 1.3 times per week Multiple times in half load 14.0 49 l water consumption per cycle 9.1 Maxed efficiency 9.1 Direct intake - 3.5 l by intake and 5.5 l for kitchen use 9.0 1 litre reduction in kitchen use 8.0 Another half-litre reduction in kitchen use 7.5 Other miscellaneous 9.0 1 litre reduction in other uses 8.0 Another 1 litre reduction in other uses 7.0 Total water consumption 130.0 Total water consumption 92.4 Total water consumption 72.2 Greywater generated (except shower) 19.7 30% of recycled greywater (ex. Hydraloop) -5.9 75% of recycled shower water (ex. Orbit Shower) -18.0 Total water consumption utilising recycled water 48.3 All quantity of water is estimated in lpcd. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 35 5 Recommendations To emphasise the need for water conservation effective strategies must integrate technological innovation, behavioural change, economic instruments, and public engagement to ensure sustainable water management. The following recommendations outline practical and policy- oriented measures that can contribute to long-term water sustainability at the household and community levels. • Installation of water-efficient fixtures, such as low-flow bathroom and kitchen faucets and showerheads with aerators to reduce household water consumption. Furthermore, policy interventions should mandate manufacturers to limit the production of faucets with excessive flow rates and require builders to incorporate water-efficient systems in all new developments. • Volumetric pricing system should be established with the incorporation of telescopic tariff scheme by the municipality (water service provider) to incentivize responsible water users. • Prioritize widespread adoption of greywater recycling systems to reduce water consumption significantly and make the 50L home achievable. • Educational initiatives should focus particularly on the younger generation, fostering long-term awareness and commitment to water conservation practices. • Sustained efforts in technological research and development of fresh, innovative technologies for water saving is crucial for increased water efficiency. This can also be achieved by organising competitive events offering monetary prizes and prestigious awards thereby encouraging university students and manufacturers of appliances and fixtures to participate. • A greater level of awareness campaigns over wide public exposure should be conducted to promote behavioural change and community engagement in water conservation efforts. • Internet of Things (IoT) based smart water management systems attached to IMD should be enabled in all households, facilitating real-time monitoring and user engagement via mobile applications and digital platforms. CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 36 6 Conclusion This study aimed to investigate and identify the key drivers of per capita water consumption decline in Gothenburg, despite ongoing population growth and urban expansion. Through triangulating quantitative data, technical analysis, policy regulations, and behaviour-based surveys, a comprehensive understanding has been gained. The findings indicate that this trend cannot be attributed to an individual factor but rather is a result of interactions between technological advancements, passive infrastructural improvements, regulatory reforms, and nuanced behavioural shifts. While consumer awareness and intentional conservation efforts exhibit variability, the widespread integration of water- efficient fixtures and appliances often driven by voluntary commitments to sustainability exceeding industry standards has had a profound effect on household water usage patterns. Moreover, the integration of modern technologies and new policy approaches, such as the introduction of volumetric tariffs and IoT-based smart metering, holds great potential for further reductions. Regulatory changes, in coordination with EU policy, have complemented those developments by pressuring manufacturers to adopt higher efficiency standards, many of which have been voluntarily surpassed by large brands. Although Sweden lacks binding national mandates for household water conservation, EU-mandated regulation has clearly been impactful. Although behavioural influences are considered to remain secondary, they still hold considerable significance. Survey responses showed a discrepancy between practice and awareness, indicating the need for continuous public engagement and targeted educational initiatives. The prevalence of dual-flush toilet systems and communal laundry facilities underscores how infrastructure design can facilitate conservation independently of deliberate consumer behaviour. Significantly, the findings also infer that strategic policy interventions, such as volumetric pricing reforms introduced and individual metering systems implemented, would additionally enhance conservation efforts and influence behavioural change. The case study of Coimbatore’s telescopic tariff model provides an economically viable as well as socially fair model that may be adapted in the Gothenburg context. Notably, this decline in water consumption trend has not resulted in a diminished quality of life, suggesting that conservation should be framed not merely as a technical or behavioural challenge but as an opportunity for innovative design and governance. The Gothenburg case study emphasizes that sustainable consumption can be achieved by means of systems-level thinking, passive efficiency solutions, and supportive policies, rather than through restrictive regulations. 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