Water and SDG 3: Why Health Outcomes Depend on Reliable Water Service

Children under five carry the heaviest share of this burden. Diarrhoeal disease alone is the most legible example of how a missing water service translates almost immediately into preventable mortality. The harder questions, which this article takes on, are why the global decline in water-related disease deaths has slowed in the places that need it most, why the neglected tropical disease agenda still depends on infrastructure that is not being delivered, and why a hospital without running water can be a place where new infections start rather than where they end.

FairAction is a research-led water charity advancing SDG Target 6.1: universal and equitable access to safe and affordable drinking water for all. Our work has been concentrated in Nigeria, where over more than nine years we have mapped 1,700 communities, catalogued 265 sustainability challenges that undermine lasting water service, and validated a predictive sustainability model through live, longitudinal field deployments. The mission is global. Nigeria is where the model is being built and proven; it is designed to be adapted and scaled to the other regions where SDG 6.1 is hardest to deliver.

SDG 3 is where the cost of failing to deliver SDG 6.1 is counted most directly in lives. The water deprivation that prevents a community from drinking safely is the same deprivation that fills its under-five wards with diarrhoeal disease, that lets schistosomiasis and trachoma persist where the infrastructure to interrupt them does not, and that means birth attendants in too many maternity units still cannot wash their hands when it matters most. The places where SDG 6.1 is hardest to deliver are the places where SDG 3 is most off track.

The 2025 edition of the WHO and UNICEF Joint Monitoring Programme report is the most authoritative current source on global progress. Roughly one in four people, around 2.1 billion in total, still lack safely managed drinking water, including 106 million who drink directly from untreated surface sources. Around 3.4 billion lack safely managed sanitation. The health consequences are measured in WHO's latest burden of disease estimates: around 1.4 million people die each year as a result of inadequate drinking water, sanitation and hygiene, with unsafe sanitation accounting for around 564,000 of those deaths.[1][2]

Around 60 per cent of all diarrhoeal deaths globally are attributable to WASH risk factors. The most recent systematic update from Prüss-Ustün and colleagues estimated that 829,000 diarrhoeal deaths and around 49.8 million disability-adjusted life years are caused each year by inadequate water, sanitation and hygiene, around 297,000 of those deaths in children under five.[5] The 2024 Global Burden of Disease update confirms that diarrhoeal mortality has fallen from 2.9 million annual deaths in 1990 to around 1.2 million in 2021, but children under five still carry the highest mortality rate of any age group.[6]

SDG 3 contains thirteen targets, from maternal mortality to non-communicable diseases to mental health. Three of them carry water inside them in ways the sector under-acknowledges. These are the three this article focuses on.

The water and health sectors have delivered a remarkable amount in three decades, and it is worth being honest about that before pivoting to what they have not. Global diarrhoeal mortality has fallen by around 60 per cent since 1990, with the steepest decline, around 79 per cent, in children under five. Oral rehydration therapy, rotavirus vaccination, expanded access to improved sources and slow but real sanitation progress have saved hundreds of millions of lives.[6]

The NTD picture is similarly encouraging on the headline number: a 32 per cent reduction in people requiring interventions since 2010, elimination of at least one NTD in 56 countries, and the near-eradication of guinea worm, achieved through sustained mass drug administration funded by long-running coalitions.[8] Healthcare facility WASH has finally moved onto the global monitoring radar, none of which existed a decade ago.[10] And between 2015 and 2024, around 961 million additional people gained safely managed drinking water, lifting global coverage from 68 to 74 per cent.[1]

The hardest finding is that the steady global decline in water-related disease deaths has not reached the regions where the burden is highest. The same JMP report that records 961 million people lifted into safely managed services also notes that 2.1 billion still go without, that the gains are concentrated in middle-income countries, and that progress in fragile contexts and rural sub-Saharan Africa has been far slower.

On the household side, the binding constraint is the gap between water access and water service. A handpump that breaks within three years, or delivers contaminated water in the dry season, is not preventing diarrhoeal disease. The rural water literature is converging on the finding that the variable for health outcomes is not whether a household has an improved source on paper, but whether the service is reliable enough to change actual disease exposure. When a rural waterpoint fails, it takes a month or more to repair.[12] A month-long outage in the dry season, when alternative sources are unsafe, is the kind of failure that fills paediatric wards.

On the facility side, the gap is starker still. Healthcare facility WASH is not a sub-sector or an add-on. It is a primary determinant of whether the rest of the health system can deliver on its mandate, and a first-order driver of the antimicrobial resistance that WHO ranks among the top ten threats of the century.[13][14] On the NTD side, the elimination progress masks a structural dependency: trachoma needs face-washing, schistosomiasis control needs safe alternatives to contaminated water, and WHO has stated plainly that WASH is critical to the prevention and management of every NTD scheduled for control or elimination by 2030.[15]

Access is not service. Water systems support SDG 3 only while reliable service continues.

Each of these positions is contested within the sector. We set them out because we think the contest matters.

The scale of the failure shaped how the FairAction Model was built. Of the 1,700 communities mapped in Oyo, Osun and Ekiti states, 49.8 per cent lack any improved water source at all. Of the 856 that do have infrastructure, 418, around half, have already failed. Roughly one in four mapped communities is a place where an investment was made and lost. The problem the model solves is not the absence of investment. It is the absence of a system that converts investment into water service that lasts.[16] The model integrates three functions as a single connected practice.

1Diagnose & design

Each community on its own terms

Local conditions, governance, geography and patterns of past failure are read together before any solution is committed. The diagnostic work is grounded in a systematic review of the literature and the mapping of more than 1,700 communities, from which 265 sustainability challenges have been catalogued to drive the model's predictive logic.

2Implement & learn

Services, not projects

Every deployment carries continuous performance learning embedded in it, treating implementation as the point at which evidence begins rather than ends. Five Smart Water Infrastructures are under continuous monitoring across more than sixteen metrics, each both a service for its community and a continuously updating asset to the model.

3Strengthen & scale

Every community makes the next one better

What works is held inside the model and used to expand the work, shared and adapted to new regions through frameworks, tools and partnerships. The underlying research has been published in six peer-reviewed international water journals and a doctoral thesis at the University of Technology Sydney, providing the external scientific review the model rests on.

This is the architecture by which FairAction turns the analytical claims in this article into a working system. Water service quality is the binding constraint on health outcomes; the way to deliver it at scale is a model that diagnoses each community correctly, implements with continuous learning embedded, and strengthens itself with every deployment. The evidence that it works is on the ground in Nigeria, accumulating in real time.[16]

If you fund global health, this article is a case for where the money goes. The evidence points to one operational conclusion: the single most cost-effective contribution to SDG 3 outcomes in the communities that need it most is not another clinic, drug procurement round or vertical disease programme. It is sustained water service that keeps working in year three, year five and year ten.

• Treat water service quality as the binding constraint. SDG 3.2, on preventable child deaths, will not be met in sub-Saharan Africa on the current trajectory of WASH service delivery, and the gap will be measured in children's lives.
• Close the healthcare facility WASH gap. Around 1.7 billion people use facilities without basic water; the resulting maternal and neonatal deaths and resistance pressure are first-order failures of SDG 3.1. The monitoring infrastructure now exists; the funding must follow.
• Fund prevention, not parallel tracks. The NTD elimination agenda is structurally dependent on water infrastructure delivered at the same pace as the drug campaigns. Water-related disease prevention belongs in the same conversation as drug procurement.
• Back durable service, not one-off installations. The FairAction Model is built to deliver it: 4.7 years of continuous monitoring at Abeku, 100 per cent sustainability, 98.7 per cent reliability, across five Smart Water Infrastructures and a research base spanning 1,700 mapped communities.

The model is built to be adapted beyond Nigeria, to the other regions where SDG 6.1 is hardest to deliver and the health consequences of failure are highest. We invite donors, foundations and institutional funders who share this view to engage with us directly on how a sustainable service approach can be embedded in the programmes you support.[16]