Water scarcity already affects more than 2 billion people worldwide, according to UN Water. By 2050, projections suggest that number could reach nearly half the global population as demand rises and climate change disrupts freshwater supply.
Water scarcity refers to a condition where the available freshwater resources in a region are insufficient to meet the demands of its population and economy. Unlike a temporary drought, water scarcity can be a permanent structural condition driven by geography, population density, and infrastructure.
Below, you will learn the types and causes of water scarcity, which countries are most affected, how it is measured, and what organizations can do to assess their exposure.
What Is Water Scarcity?
Water scarcity occurs when the demand for freshwater in a region exceeds the available supply on a sustained basis. Hydrologists distinguish between two types:
- Physical water scarcity: Not enough water exists to meet all demands. Arid and semi-arid regions like the Middle East, North Africa, and parts of Central Asia face physical scarcity where renewable supply is inherently low relative to population and agricultural needs.
- Economic water scarcity: Water exists in nature but cannot be accessed due to lack of infrastructure, investment, or governance. Much of sub-Saharan Africa faces economic scarcity. Rivers and aquifers contain adequate water, but communities lack the pipes, treatment plants, and distribution systems to deliver it.
Is there a scarcity of water? On a global level, the total volume of freshwater on Earth has not changed. But the distribution is profoundly unequal, and demand has grown six-fold over the past century. Water scarcity is a local problem with global consequences.
Causes of Water Scarcity
Water scarcity results from multiple factors working together. No single cause explains why a region runs short of water. The primary drivers include:
1. Population growth. More people require more water for drinking, cooking, sanitation, and food production. Regions where population growth outpaces infrastructure investment face escalating water scarcity.
2. Agricultural demand. Agriculture consumes approximately 70% of global freshwater withdrawals, according to the FAO. Irrigation-intensive crops like rice, cotton, and sugarcane in arid regions draw enormous volumes from rivers and aquifers.
3. Climate change. Rising temperatures increase evaporation, shift precipitation patterns, and accelerate glacier and snowpack melt. Regions that depend on seasonal snowmelt for summer water supply face declining flows as glaciers shrink.
4. Groundwater depletion. Over-extraction of groundwater for agriculture and industry lowers water tables faster than natural recharge can replenish them. The Ogallala Aquifer in the United States, the Indo-Gangetic aquifers in South Asia, and the North China Plain aquifer are all declining at unsustainable rates.
5. Pollution and contamination. Industrial discharge, agricultural runoff, and untreated sewage can render water sources unusable even where physical supply is adequate. Water scarcity is not only about quantity but also about quality.
6. Poor infrastructure. Aging or nonexistent distribution systems lose 20 to 30% of treated water to leaks before it reaches users. Lack of storage capacity means seasonal rainfall is not captured for dry periods.
Effects of Water Scarcity
Water scarcity creates cascading impacts across health, agriculture, industry, and geopolitics:
- Food insecurity: Crop yields drop sharply in water-scarce basins. Irrigated agriculture, which produces roughly 40% of the world’s food on just 20% of cultivated land, is especially vulnerable to supply disruptions.
- Public health: Water scarcity forces communities to rely on contaminated sources, increasing waterborne diseases. Women and children in water-scarce regions often walk hours for collection, reducing time for education and economic activity.
- Economic disruption: Manufacturing, energy generation, and mining operations require reliable water access. Facilities in water-scarce basins face production shutdowns, rising input costs, and regulatory restrictions on withdrawals.
- Ecosystem degradation: Rivers, wetlands, and lakes shrink when human withdrawals leave insufficient flows for ecosystems. Biodiversity loss, fishery collapse, and soil salinization follow.
- Conflict and migration: Competition for scarce water resources can intensify tensions between communities, regions, and even countries that share river basins. Water scarcity is a recognized driver of climate-related migration.
Water Scarcity by Country
The severity of water scarcity varies enormously by region. WRI Aqueduct data ranks countries by baseline water stress, which closely correlates with scarcity risk:
| Region | Countries With Extreme Stress | Primary Driver |
|---|---|---|
| Middle East | Qatar, Kuwait, Bahrain, UAE, Saudi Arabia | Arid climate, high per-capita demand |
| North Africa | Libya, Egypt, Tunisia | Low rainfall, growing populations |
| South Asia | India, Pakistan, Afghanistan | Massive population, agricultural demand |
| Central Asia | Uzbekistan, Turkmenistan | Cotton irrigation, shrinking Aral Sea |
| Southern Europe | Parts of Spain, Italy, Greece | Seasonal drought, tourism demand |
| Sub-Saharan Africa | Somalia, Niger, Burkina Faso | Economic scarcity, limited infrastructure |
India deserves particular attention. With roughly 18% of the world’s population but only 4% of its renewable water resources, India faces water scarcity at a scale that affects over a billion people. The Ganges, Indus, and Brahmaputra basins all register high to extreme stress scores.
Measuring Water Scarcity
Several indicators quantify water scarcity at different scales:
- Falkenmark indicator: Measures renewable freshwater per capita per year. Below 1,700 m³ indicates stress; below 1,000 m³ indicates scarcity; below 500 m³ indicates absolute scarcity.
- Baseline Water Stress (BWS): From WRI Aqueduct, measures withdrawal-to-supply ratio at the basin level. Scores above 2.5 indicate high stress; above 4.0 indicates extreme stress.
- Water Exploitation Index (WEI): Used by the European Environment Agency, similar to BWS but calculated at the national or regional level. A WEI above 20% indicates water scarcity risk.
For organizations assessing exposure across multiple locations, basin-level metrics from Aqueduct provide the most actionable data. A detailed water risk assessment can screen hundreds of sites against these indicators simultaneously.
What Organizations Can Do
Water scarcity is a structural risk that cannot be solved at the facility level alone. However, organizations can take concrete steps to understand and manage their exposure:
- Screen all locations: Run a climate vulnerability assessment that includes water stress as a hazard. Identify which facilities, suppliers, and logistics hubs sit in high-stress basins.
- Assess supply chain exposure: Tier-1 and tier-2 suppliers in water-scarce regions represent hidden risk. Agricultural and manufacturing suppliers are especially vulnerable.
- Monitor projections: Basin-level water stress is expected to worsen under all SSP scenarios through 2050. Monitoring future projections helps organizations plan ahead rather than react to disruptions.
- Report accurately: CDP Water Security and TCFD frameworks require disclosure of water-related risks. Basin-level Aqueduct data provides the evidence base for accurate reporting.
Frequently Asked Questions
What is water scarcity?
Water scarcity is a condition where the available freshwater resources in a region are insufficient to meet the demands of its population and economy. It can be physical (not enough water exists) or economic (water exists but cannot be accessed due to lack of infrastructure). Over 2 billion people currently live in water-scarce conditions.
What are the main causes of water scarcity?
The six primary causes of water scarcity are population growth, agricultural demand (70% of global withdrawals), climate change (shifting rainfall and glacier melt), groundwater depletion, pollution and contamination, and poor infrastructure. These factors typically reinforce each other in affected regions.
Is there a scarcity of water globally?
The total volume of freshwater on Earth has not changed, but its distribution is profoundly unequal. Over 2 billion people live in countries experiencing high water stress, and that number is projected to grow. Water scarcity is a local and regional problem with global consequences.
What are the effects of water scarcity?
Water scarcity leads to food insecurity, public health crises from contaminated sources, economic disruption through factory shutdowns and rising costs, ecosystem degradation as rivers and wetlands shrink, and in severe cases, conflict and migration as communities compete for limited resources.
Which countries face the worst water scarcity?
Countries facing extreme water scarcity include Qatar, Kuwait, Bahrain, UAE, and Saudi Arabia in the Middle East; Libya, Egypt, and Tunisia in North Africa; and India, Pakistan, and Afghanistan in South Asia. India is particularly significant, holding 18% of the world’s population but only 4% of its renewable water resources.
Conclusion
Water scarcity is a structural condition affecting over 2 billion people today, with projections showing significant worsening through 2050. The causes are well understood: population growth, agricultural demand, climate change, groundwater depletion, pollution, and infrastructure gaps. For organizations with operations, assets, or suppliers in water-scarce regions, basin-level data from WRI Aqueduct provides the clearest picture of current and future exposure. Screening your locations against water scarcity indicators is a practical step toward managing one of the most consequential environmental risks of this century.
