Water Scarcity
2.1 billion people lack access to safely managed drinking water, and 3.5 billion lack safe sanitation. Unsafe water still kills hundreds of thousands of children a year, from a problem that treating the water can solve for pennies per person.
Estimated child deaths from diarrhoeal disease so far this year, mostly from unsafe water and sanitation.
2.1 billion people, about 1 in 4 globally, lack access to safely managed drinking water, including 106 million who drink directly from untreated surface water like rivers and ponds (WHO/UNICEF Joint Monitoring Programme, 2024/2025).
3.5 billion people lack safely managed sanitation, including 419 million who still practice open defecation entirely (WHO/UNICEF Joint Monitoring Programme, 2023).
Diarrhoeal disease kills an estimated 443,800 children under 5 and 50,900 children aged 5 to 9 every year, and more than 90 percent of those deaths trace back to unsafe drinking water, inadequate sanitation, or poor hygiene (WHO, 2024).
Women and girls spend a combined 250 million hours every single day collecting water across the 53 countries with available data, more than three times the burden carried by men and boys, time taken directly from school, income, and safety (UN World Water Development Report 2026, UNESCO/UN-Water).
The global water crisis could shrink GDP by an average of 8 percent by 2050, and by up to 15 percent in the poorest countries, as it disrupts agriculture, health, and infrastructure (Global Commission on the Economics of Water, 2024).
Every $1 invested in water and sanitation returns an estimated $4.30 in reduced healthcare costs alone, before counting the added gains in productivity, school attendance, and safety (WHO, on behalf of UN-Water, 2014).
Most of this crisis isn't a technology problem, it's a delivery and maintenance problem. Evidence Action's Dispensers for Safe Water program installs free chlorine dispensers at rural water points across Kenya, Malawi, and Uganda, letting people treat water for waterborne pathogens right where they already collect it. It's one of GiveWell's top-rated global health interventions, costing an estimated $1.22 to $1.87 per person served and cutting all-cause under-5 mortality by an estimated 6 to 11 percent, roughly 5 times as cost-effective as an unconditional cash transfer. GiveWell did revise its estimate down in 2025 after finding lower real-world dispenser usage in Kenya than assumed, a reminder that even the best-evidenced interventions need ongoing scrutiny, not just a one-time stamp of approval.
Sources: WHO/UNICEF Joint Monitoring Programme, WHO ("Diarrhoeal disease" fact sheet, 2024), UN World Water Development Report 2026 (UNESCO/UN-Water), Global Commission on the Economics of Water (2024), WHO/UN-Water GLASS report (2014), GiveWell cost-effectiveness analysis
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Runs Dispensers for Safe Water, installing free chlorine dispensers at rural water points across Kenya, Malawi, and Uganda so people can treat water for waterborne pathogens right where they collect it. One of GiveWell's top-rated global health interventions.
