About 2.1 billion people, roughly 1 in 4 worldwide, lack access to safely managed drinking water. That figure comes from a 2025 report by the WHO and UNICEF, which also found that 106 million of those people drink directly from untreated rivers, lakes, or streams with no treatment whatsoever.
What “Clean Water” Actually Means
The 2.1 billion figure depends on how you define “clean water,” and the global standard uses a five-tier system. At the top is “safely managed” water: an improved source located on your property, available when you need it, and free from fecal and chemical contamination. This is the benchmark the United Nations uses, and it’s the standard that 2.1 billion people fail to meet.
Below that, “basic” water means an improved source (a borehole, protected well, piped supply, or similar) within a 30-minute round trip including waiting time. “Limited” water comes from the same types of sources but requires more than 30 minutes of travel. “Unimproved” means drinking from an unprotected well or spring. And at the bottom, “surface water” means drinking straight from a river, pond, or canal.
So when headlines say billions lack clean water, they’re counting everyone below that top tier. Many of these people do have some water access, but the water may be contaminated, unreliable, or far from home. The 106 million drinking untreated surface water face the most extreme risk.
Where the Crisis Is Concentrated
The water gap is not evenly distributed. Sub-Saharan Africa and parts of Central and Southern Asia bear the heaviest burden. Rural communities are hit hardest: as of the most recent global tracking data, roughly 96% of urban residents had access to improved water sources compared to about 82% of rural populations. That gap has narrowed over time (rural access was just 62% in 1990), but tens of millions of people in remote areas still rely on unprotected sources or spend hours collecting water each day.
The divide isn’t always about rainfall or geography. Researchers distinguish between physical water scarcity, where there simply isn’t enough water to go around, and economic water scarcity, where water exists but infrastructure to deliver it doesn’t. An estimated 1.2 billion people live in regions that are physically running low on water. Another 1.6 billion live in places where water is available but governments or communities lack the investment to pipe, treat, and distribute it. In many of the hardest-hit countries, the problem is infrastructure and funding, not the absence of water itself.
Health Consequences of Unsafe Water
Contaminated water is a direct pathway for diseases like cholera, typhoid, and dysentery. Cholera alone causes an estimated 1.3 to 4 million cases and 21,000 to 143,000 deaths globally each year. In 2023, over 535,000 cholera cases and 4,000 deaths were reported to the WHO from 45 countries. Those are only the reported numbers; actual cases are likely far higher in regions with limited health surveillance.
Diarrheal disease, much of it caused by contaminated water, remains one of the leading killers of young children worldwide. Children under five are especially vulnerable because repeated bouts of diarrhea cause dehydration and malnutrition, which compound each other. A child who is malnourished gets sicker from waterborne infections, and a child with chronic diarrhea can’t absorb enough nutrients to grow properly.
Economic Cost of Dirty Water
The damage extends well beyond health. Research tracking river pollution and economic output across countries found that when rivers become moderately polluted, economic growth in downstream regions drops by about 1.4%. Heavy pollution cuts growth by 2%. In middle-income countries, those losses are even steeper, reaching 1.77% to 2.5% of economic growth.
These numbers reflect a cascade of costs: lost workdays from illness, medical expenses, reduced agricultural productivity from contaminated irrigation, and the sheer time lost to water collection. In many communities, women and girls spend hours each day walking to water sources, time that could otherwise go toward school or income-generating work. The economic drag of unsafe water reinforces the poverty that makes clean water infrastructure hard to build in the first place.
The Sanitation and Hygiene Gap
Water access is only one piece of the picture. The same 2025 WHO/UNICEF report found that 3.4 billion people lack safely managed sanitation, including 354 million who still practice open defecation. Another 1.7 billion lack basic hygiene services at home, and 611 million of those have no handwashing facilities at all. Without sanitation and hygiene, even improved water sources can become contaminated through runoff, poor waste management, or unwashed hands. The three issues are deeply interconnected: solving one without the others leaves communities vulnerable.
Progress and Remaining Gaps
The situation has improved significantly over the past few decades. Rural access to improved water sources jumped from 62% in 1990 to 82% by 2012, and coverage has continued to expand since. Billions of people gained access to better water during that period, driven by investment in wells, piped systems, and water treatment.
But the remaining gap is the hardest to close. The communities still without safe water tend to be the most remote, the poorest, or the most affected by conflict and political instability. Climate change is adding pressure by altering rainfall patterns, shrinking glaciers that feed rivers, and intensifying droughts in already water-stressed regions. The 2.1 billion figure represents not just a current crisis but an increasingly complex challenge as demand for freshwater grows alongside the global population.