Vision 2030 The resilience of water supply and sanitation in the face of climate change
Technology projection study
Authors: Katrina Charles (Robens Centre for Public and Environmental Health, University of Surrey) Kathy Pond (Robens Centre for Public and Environmental Health, University of Surrey) Steve Pedley (Robens Centre for Public and Environmental Health, University of Surrey) Rifat Hossain (World Health Organization) Frédéric Jacot Guillarmod (independent consultant)
Acknowledgements The authors would like to thank the many people who have made significant contributions to the preparation and revision of this report: their efforts have led to a more comprehensive and focused review of the issues than was contained in the early drafts of this report.
In particular we would like to thank everyone who responded to the questionnaire survey; to the group of experts who gave their time to be interviewed and who gave their advice, guidance and expertise freely and willingly. We would also like to acknowledge the work of the reviewers, whose valuable comments and suggestions have helped to shape the structure and content of the report.
Disclaimer
This report was prepared in good faith. The views and opinions contained in the report do not necessarily state or reflect those of the World Health Organization, Department for International Development, UK and University of Surrey, UK. The named authors alone are responsible for the views expressed in this publication. Neither the World Health Organization, Department for International Development, UK and University of Surrey, UK, nor their employees, contractors or subcontractors, make any warranty, express or implied, or assume any legal liability or responsibility for its accuracy, completeness, or any party’s use of its contents.
This report is not edited by the World Health Organization to conform to the full requirements of WHO. The published material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall the World Health Organization be liable for damages arising from its use.
Contents
1. INTRODUCTION ...... 1
2. LITERATURE REVIEW ...... 4 2.1 Vulnerability and adaptation to climate change ...... 6 2.2 Vulnerability and adaption of water supplies to climate change ...... 8 2.2.1 Piped water supply ...... 9 2.2.2 Facilities dependent on groundwater ...... 12 2.2.3 Facilities dependent on rainwater catchment and storage...... 17 2.3 Vulnerability and adaptation of sanitation to climate change ...... 18 2.3.1 Sewer systems ...... 19 2.3.2 Septic tanks ...... 22 2.3.3 Pit latrines ...... 22 2.4 Broader strategies for adaptation...... 25 2.4.1 Understanding vulnerability at a community level ...... 25 2.4.2 Informed decision making ...... 28 2.4.3 Risk reduction...... 31 2.5 Climate change: implications for water resources and health ...... 32 2.5.1 Climate observations ...... 33 2.5.2 Climate predictions ...... 38 2.5.3 Observations and predictions of the impact of climate change on water resources and health ……...... 39 2.6 Key outcomes ...... 48
3. OPINIONS: VIEWS FROM PROFESSIONALS IN THE WATER INDUSTRY ...... 48 3.1 Methods ...... 49 3.1.1 Questionnaire survey ...... 49 3.1.2 Telephone interviews ...... 51 3.2 Results ...... 53 3.2.1 Observations related to changes in weather patterns ...... 54 3.2.2 Year to year changes in drinking water sources ...... 56 3.2.3 Climate predictions ...... 57 3.2.4 Vulnerability and reliability (in terms of quality and quantity) of the facilities ...... 58 3.2.5 Changing use of drinking water supply and sanitation facilities ...... 62 3.2.6 Policy issues ...... 63 3.3 Key outcomes ...... 68
4. FORECAST OF WATER AND SANITATION COVERAGE IN 2020 ...... 69 4.1 Forecasting method ...... 69 4.1.1 JMP linear regression method ...... 70 4.1.2 Long term forecasting method ...... 70 4.2 Limitations of the forecasting data and method ...... 71 4.3 Forecasts for water supply and sanitation facilities ...... 72 4.3.1 Summary of progress ...... 73 4.3.2 Types of improved water supply and sanitation facilities ...... 76 4.4 Key outcomes ...... 78
5. DETERMINING THE RESILIENCE OF WATER SUPPLY AND SANITATION FACILITIES TO CLIMATE CHANGE ...... 78 5.1 Piped water supplies ...... 80 5.1.1 Increased rainfall ...... 81 5.1.2 Decreased rainfall ...... 82 5.1.3 Increased intensity of rainfall ...... 82 5.2 Protected wells ...... 82 5.2.1 Increased rainfall ...... 83 5.2.2 Decreased rainfall ...... 83 5.2.3 Increased intensity of rainfall ...... 83 5.3 Protected springs ...... 84 5.3.1 Increased rainfall ...... 84 5.3.2 Decreased rainfall ...... 84 5.3.3 Increased intensity of rainfall ...... 84 5.4 Rainwater collection ...... 85 5.4.1 Increased rainfall ...... 85 5.4.2 Decreased rainfall ...... 85 5.4.3 Increased intensity of rainfall ...... 85 5.5 Connection to public sewers ...... 86 5.5.1 Increased rainfall ...... 86 5.5.2 Decreased rainfall ...... 86 5.5.3 Increased intensity of rainfall ...... 87 5.6 Connection to septic tanks ...... 87 5.6.1 Increased rainfall ...... 87 5.6.2 Decreased rainfall ...... 87 5.6.3 Increased intensity of rainfall ...... 88 5.7 Improved pit latrine ...... 88 5.7.1 Increased rainfall ...... 88 5.7.2 Decreased rainfall ...... 88 5.7.3 Increased intensity of rainfall ...... 89 5.8 Resilience matrices ...... 89
6. CONCLUSIONS: THE RESILIENCE OF WATER SUPPLY AND SANITATION FACILITIES TO CLIMATE CHANGE ...... 93
REFERENCES ...... 96
Appendix 1 Questionnaire Appendix 2 Interview guide Appendix 3 List of respondents to the questionnaire and interviews Appendix 4 Full questionnaire results Appendix 5 Projections of water and sanitation coverage for 2020 by country Appendix 6 Maps for projections of water supply and sanitation coverage for 2020
1. Introduction
It is now widely accepted that some degree of future climate change is inevitable and that significant impacts will be felt via water (Bates et al., 2008). The impacts of climate change on water supply and sanitation are very likely to directly affect the achievement of the Millennium Development Goals (MDGs) in some areas. Although access to safe water supplies and hygienic sanitation is relevant to all the MDGs, the most important challenge in the context of the present project is MDG target 7c: to halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation (UNDP, 2007).
If any of the predicted consequences of climate change, such as higher average temperatures, increased rainfall, or rising seawater levels, were to affect the viability of drinking water supply and sanitation facilities, two critical problems for the future will arise: (a) The cost of achieving the MDGs will increase, because higher cost technologies will be required to deliver services. (b) Households and communities currently with access to improved facilities might see that access removed by the destruction of water or sanitation infrastructure, or by the deterioration of water supplies, resulting in the reversal of progress towards the MDGs, and potentially leading to the displacement of populations.
The impact of climate change on access to drinking water supply and sanitation facilities will vary both by region (in terms of the specifics of the change in climate expected) and by facilities (in relation to the vulnerability of the facility to the expected change in climate). To date, although such problems have been highlighted as serious and likely consequences of climate change by the Intergovernmental Panel on Climate Change (IPCC, 2007), there has been very little systematic assessment of the potential impacts. Where studies have been done, the conclusions are often quite broad (for example, that increased flooding increases the risks of contamination of water supplies) or based on limited evidence. Furthermore, the recommendations from these studies tend to make general statements about the need for research, rather than identifying needs for more targeted research on key regions and facilities most likely to be affected by climate change. This highlights the need for further research to improve water and sanitation provision.
The present report provides information on drinking water supply and sanitation facilities and their vulnerabilities to climatic events, as background for directing policy on drinking water supply and sanitation development to minimize the potential impact of climate change on MDG target 7c. Progress towards this target is being monitored by a joint initiative of WHO and UNICEF – the WHO/UNICEF Joint Monitoring Programme on Water Supply and Sanitation (JMP) (JMP, 2008). The JMP reports on the status of improved water supply and sanitation facilities, and relates its finding to the delivery of the MDG target 7c. The aim is to support countries in their efforts to monitor this sector, and help countries and international bodies make evidence based policies, enabling better planning and management. The facilities described in the JMP report range from low cost on site systems for water supply and sanitation to large scale piped water and sewerage networks.
Understanding the likely impacts of climate change on water supply and sanitation will help to provide a platform for the discussion of future changes to the criteria used by the JMP for assessing the progress toward the MDG target 7c. This is becoming increasingly urgent, as a new system will need to be in place and agreed by 2015 to prevent any significant gap in reporting. 1
The present report aims to provide data to inform policy decisions within the United Kingdom Department for International Development (DFID) and WHO for drinking water supply and sanitation, in the light of climate change. The timescale of the project, as well as the complex interactions between climate change, water resources, and drinking water supply and sanitation, required the scope of the project to be clearly defined to concentrate on the drinking water supply and sanitation facilities that are most relevant for future policy development, and on climate conditions that are most likely to affect the operation and management of these facilities.
Regarding climate, the report focuses on changing rainfall patterns. While there will be impacts from other changes in climate (temperature, sea level, and so on), changes in rainfall, and their consequences for water resources, are considered to have the greatest potential impact on water supply and sanitation facilities.
Regarding drinking water supply and sanitation facilities, the scope of the present report is limited to improved facilities because they are the focus of water and sanitation policy. An improved drinking water source is one that is likely to provide “safe” water (JMP). Sanitation systems are considered adequate if they are private and if they separate human excreta from human contact. Improved drinking water supply and sanitation facilities include (JMP, 2008):
Drinking water supply • Piped water • Public standpipes • Protected wells • Protected springs • Rainwater collection
Sanitation • Piped sewer system • Septic system • Pit latrines including ventilated improved pit latrines, pour –flush latrines, and pit latrine with slabs • Composting toilets
We recognize that a number of possible, specific impacts of climate change have not been included in the present work; for example: coastal inundation; saline intrusion; vectors of disease; emergency responses; and indirect effects of climate change. However, the significant impacts on drinking water supply and sanitation identified within the scope of the present report provide sufficient reason for policy development within the water and sanitation sector. Future studies into more specific impacts of climate change will be important in order the refine these policies.
Two timescales (up to 2020 and up to 2030) were used for the policy decisions, and hence were a focus of this report and the corresponding report on climate change predictions. For the present study, the year 2020 was selected to represent the minimum expected lifespan of technologies that had been installed to date, including recent efforts to meet the MDG target in 2015. The projected situation in 2020 provides an indication of the potential for climate change to undermine short term sustainability, and reflects current and historical programming, policy decisions and current climatic variability. The principal consequences of changes by 2020 relate to the management of infrastructure already, or soon to be, in operation.
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The present document draws clear lines between the impact of changing rainfall patterns and the sustainability of different drinking water supply and sanitation facilities. It provides an analysis of the number of people served in each region by different facilities as a basis for analysing the potential impact of climate change on progress towards the achievement of MDG target 7c. The definitions of vulnerability, adaptive capacity (or adaptability) and resilience, from the IPCC Working Group II (IPCC, 2007), used throughout this report are given below.