In this paper we outline different theoretical approaches, namely outcome vulnerability, contextual vulnerability, and resilience, for addressing climate change effects in the context of water, sanitation, and hygiene (WASH) services. We analysed how these three approaches were employed in the WASH-climate change nexus literature, and discuss the implications for WASH research, policy, and development work. Our analysis of 33 scholarly WASH-climate change nexus papers found that they implicitly drew most frequently on an outcome vulnerability approach that tended to focus on the impact of projected climate change hazards on physical aspects of WASH service delivery. Each individual approach has limitations due to their disciplinary and epistemological foundations and the WASH sector in particular must be mindful of who stands to benefit most and what values will be upheld when these approaches are used. We argue that in most cases it will be beneficial to draw on all approaches and describe challenges and opportunities for integrating different perspectives on preparing for climate change within the WASH sector.

This paper explores the physical, social, and environmental dimensions of how climate change impacts affect drinking water safety in a rural context in developing countries. Climate impacts, such as contamination or the reduced availability of preferred drinking water sources due to climate-related hazards, threaten water safety in rural areas and these impacts will likely worsen as climate change accelerates. We qualitatively examined these impacts in a community in rural Vanuatu using three approaches side-by-side: adaptation, vulnerability, and resilience. We employed a mixed methods case study methodology that combined semi-structured interviews, technological and environmental surveys, and observations. We demonstrate the influence of physical infrastructure design, social structures mediating water access, and the availability of multiple sustainable water resources on water safety with respect to climate impacts. We also show how the initial problematization of how climate affects water safety can influence subsequent actions to address, or overlook, issues of infrastructure design and maintenance, social equity, and natural resource management for water access. Improvements to rural drinking water safety management in the context of climate change should take a pluralistic approach, informed by different conceptualizations of climate impacts, to account for the varied causal pathways of reduced water safety for different members of a community.

Significant progress is needed, in both large cities and small towns, to meet the ambitious targets set at international and national levels relating to universal access to safely managed sanitation. There has been increased recognition in the urban sanitation sector that in rapidly growing cities, there is unlikely to be a single centralized sanitation solution which can effectively deliver services to all demographics, and that heterogeneous approaches to urban sanitation are required. At the same time, due to competing investment priorities, there is a greater focus on the need for sanitation investments to address multiple objectives. However, calls for more informed sanitation planning and a more dynamic and disaggregated approach to the delivery and management of sanitation services have had limited impacts. This is in part due to the complexity of the drivers for sanitation investment, and the difficulties involved in identifying and addressing these multiple, often conflicting, goals. This paper examines three potential drivers of citywide sanitation decision-making-public health, sustainability and economic performance-via the three proxies of contamination, climate change and costs. It examines the importance of each driver and proxies, how they are considered in investment decisions, the current state of knowledge about them, and priority aspects to be included in decisions. At present, while public health is a common driver for improving sanitation, there are significant gaps in our understanding of fecal contamination spread and exposure, and how to select sanitation solutions which can best address them. Climate change is sometimes seen as a low priority for the sanitation sector given the immediacy and scale of existing challenges and the uncertainty of future climate predictions. However, potential risks are significant, and uninformed decisions may result in greater costs and increased inequalities. Cost data are sparse and unreliable, and it is challenging to build robust cost-effectiveness analyses. Yet these are needed to compare citywide options based on least-cost over their full life cycle. This paper provides insights into how existing evidence on contamination, climate change and costs can inform decisions on sanitation investments and help chart a sustainable way forward for achieving citywide services.

A non-governmental organisation has distributed point-of-use water filtering units in the Western Division of Fiji. We sought to understand filter utilisation and water quality: both water flowing directly out of filters and stored water. We surveyed 270 households and 6 schools on filter use and performed hydrogen sulphide bacterial indicator testing on 24 water samples directly from filters and 37 stored water samples. Our response rate was 95%. Of these, only half (52%) reported consistently filtering their drinking water. Very few (8%) reported consistent use when preparing kava, a traditional drink. Factors associated with limited filter use included lost or broken filter parts (22%) (p < 0.05) and perception of source water quality as 44% of respondents who believed their source water was safe to drink reported consistent filter use compared to 68% of respondents who did not (p < 0.01). Bacterial indicator testing using hydrogen sulphide paper-strips showed that most water samples directly from the filter (71%) and from storage vessels (76%) were contaminated. Limited levels of use and high levels of contamination in both water directly from the filter and stored water raise serious questions as to the benefit of the filter even as an interim water quality solution in this setting.

Already climate-related hazards are impacting sanitation systems in Indonesia and elsewhere, and climate models indicate these hazards are likely to increase in frequency and intensity. Without due attention, to maintain existing progress on Sustainable Development Goal 6’s target 6.2 and to increase it to meet ambitions for 2030 will be difficult. City governments need new forms of evidence to respond, as well as approaches to enable them to consider sufficient breadth of strategies to adapt effectively. This paper describes a co-production research process which engaged local governments in four cities in Indonesia experiencing different climate hazards. Local government engagement took place across three stages of (i) inception and design, (ii) participation as key informants and (iii) joint analysis and engagement on the findings. We adapted and simplified a risk prioritisation process based on current literature and employed a novel framework of a ‘climate resilient sanitation system’ to prompt articulation of current and proposed climate change adaptation response actions. In contrast to many current framings of climate resilience in sanitation that focus narrowly on technical responses, the results paint a rich picture of efforts needed by city governments across all domains, including planning, institutions, financing, infrastructure and management options, user awareness, water cycle management and monitoring and evaluation. Local government commitment and improved comprehension on the implications of climate change for sanitation service delivery were key outcomes arising from the co-production process. With strengthened policy and capacity building initiatives from national level, this foundation can be supported, and Indonesian city governments will be equipped to move forward with adaptation actions that protect on-going access to sanitation services, public health and the environment.