Global warming will continue to increase the risk of more frequent, severe, or prolonged droughts and floods in many regions, although the nature and magnitude of change differ by location. Population growth, urbanization, and industrial development are increasing water demand, while pollution, land degradation and patterns of abstraction and recharge further shape water security. In 2024, only about one-third of the world’s river basins experienced normal conditions; the rest were wetter or drier than normal, marking a sixth consecutive year of widespread hydrological imbalance. All monitored glacier regions reported ice loss for the third year in a row. Groundwater-level decline is widespread. Among the 542 aquifer systems with sufficient records for comparison, groundwater-level declines had accelerated in 30%. An estimated 3.6 billion people live in areas that are potentially water-scarce for at least one month per year; this could rise to 4.8–5.7 billion by 2050.

The global record, however, is not one of unbroken decline. Between 2000 and 2024, 2.2 billion people gained access to safely managed drinking water and 2.8 billion to safely managed sanitation. Yet in 2024, 2.1 billion people still lacked safely managed drinking water, 3.4 billion lacked safely managed sanitation, and 1.7 billion lacked basic hygiene services at home. Only 56% of domestic wastewater was safely treated. Established hazards, including faecal and chemical contamination, remain urgent, while pharmaceuticals, PFAS, microplastics, and other emerging contaminants add new monitoring and treatment challenges. Microplastics are now widely detected in the water cycle, but evidence on health effects from exposure through drinking-water remains insufficient. At the current pace, universal safely managed water and sanitation services by 2030 are increasingly out of reach.

Demand is as unevenly distributed as supply. In 2023, agriculture accounted for 72% of global freshwater withdrawals, industry for 15%, and services for 13%. Water security is therefore inseparable from food systems, energy, land use, trade, and patterns of consumption. Nor can it be managed within national borders. Approximately 40% of the world’s population lives in transboundary river and lake basins. Of the 153 countries sharing waters that cross or form international boundaries, only 43 had operational arrangements covering at least 90% of their transboundary basin area in 2023. Scarcity and pollution do not mechanically create conflict. The risk of instability rises when depletion or hydrological shocks interact with unequal access, weak institutions, disrupted services, and failures of cooperation. Conversely, fair and durable arrangements for sharing water can strengthen resilience and peace.

The trajectory can still be changed. Priorities include regulating abstraction, protecting recharge areas and ecosystems, reducing leakage and avoidable losses, expanding wastewater treatment and safe reuse, and securing long-term finance and maintenance for water and sanitation systems. Groundwater decline can be slowed or reversed through regulation, managed aquifer recharge, and changes in water supply and demand. Desalination can diversify supplies in coastal settings, but its energy use, cost, and environmental effects require case-by-case assessment. Remote sensing, low-cost sensors, and interoperable data systems can strengthen monitoring and system operation. Artificial intelligence and other emerging tools remain conditional options whose benefits, costs, and governance risks require evaluation; greater digitalization also creates cybersecurity risks. Achieving clean water for all without conflict will depend on whether proven measures and context-appropriate innovation are matched by durable infrastructure, adequate finance, local capacity, and fair rules for sharing risks, costs and benefits within and across borders.

• Translate national water and sanitation commitments into costed and funded national and local delivery plans. Build the technical and institutional capacity required to implement them, including professional training and public water literacy.
• Strengthen the data foundation for water management. Maintain hydrometric, groundwater and water-quality monitoring networks; expand metering and utility-performance measurement; and publish interoperable and open data on withdrawals, allocations, leakage, service continuity and treatment performance.
• Control pollution at source, expand wastewater and sanitation services, and strengthen monitoring of emerging contaminants. Point-of-use treatment can be used as an interim or emergency safeguard.
• Strengthen integrated water resources management, maintain environmental flows, and protect and restore water-related ecosystems. In rain-fed farming areas, invest in rainwater harvesting, soil-water conservation, and carefully designed supplemental irrigation.
• Regulate groundwater abstraction. Use managed aquifer recharge while planning for both drought and flood risk.
• Expand operational agreements. Use water-conflict early-warning and risk-mapping tools to identify potential hotspots and trigger local analysis and preventive engagement.
• Align allocation and economic incentives with efficiency, equity and ecological limits. Reform subsidies that encourage overuse and protect water for low-income households.
• Transform food systems, which account for most freshwater withdrawals. Reduce food loss and support shifts toward less water-intensive diets.
• Build a circular water economy by recovering and safely reusing water, nutrients, energy, and other resources from wastewater. Support decentralized sanitation where life-cycle cost, treatment reliability and local maintenance capacity make it appropriate.
• Evaluate desalination and major supply-diversification projects, including interbasin transfers, against demand-management, reuse and ecosystem-protection alternatives, assessing these options in parallel where appropriate. Apply full lifecycle criteria covering cost, energy demand, emissions, reliability, water quality, ecological effects, equity, and residual-waste management. Increase R&D to reduce the cost, energy demand, emissions, and environmental impacts of desalination and brine management.

Sub-Saharan Africa: Water is distributed unevenly across seasons and subregions, and access depends as much on infrastructure, service quality and institutions as on physical supply. In 2024, 68% of the population used at least basic drinking-water services but only 35% used at least basic sanitation; coverage of safely managed services was lower, at 32% for drinking water and 26% for sanitation. Rapid population growth and urban expansion can therefore offset gains in coverage unless utilities and local governments can extend and maintain services fast enough.

Climate variability turns this service deficit into a resilience problem. In 2025, floods accounted for more than half of reported extreme-weather events across Africa, while drought affected more than 8.5 million people in East Africa; 60% of Africa’s population is not covered by any early warning systems. Priorities differ by place, but the shared needs are more reliable monitoring and early warning, climate-resilient WASH, maintenance of existing systems, water storage, and protection of catchments and wetlands. Groundwater can buffer dry periods and extend rural supply, but groundwater resources are unevenly distributed, and much may be difficult or costly to access or unsuitable for rapid abstraction.

Many of the region’s rivers and aquifers are shared across borders. Hydropower and irrigation can bring regional benefits but can also generate tensions when impact assessment, data exchange and operating rules are weak. Ethiopia, Egypt, and Sudan established a framework for cooperation over the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile but did not settle detailed filling and operating rules. The Cooperative Framework Agreement entered into force on 13 October 2024 and provides a legal basis for a permanent Nile River Basin Commission, although it does not bind states that have not joined. Durable water security will depend on transparent basin institutions, participation by affected communities, and finance for not only construction, but also operations, maintenance, data systems and local capacity. At least an additional US$30 billion a year is needed, while the Africa Water Vision 2063 launched in 2026 provides a longer-term continental framework.

Middle East and North Africa: MENA is the world’s most water-stressed region, while exposure and capacity differ sharply across countries. The average annual water availability is projected to fall below the absolute water scarcity threshold of 500 cubic meters per person by 2030; under current management trajectories, an additional 25 billion cubic meters per year would be needed by 2050. Climate change is intensifying the pressure. 2024 was the hottest year on record in the Arab region; drought deepened in western North Africa after six consecutive failed rainy seasons, while flash floods also affected arid Gulf states. Population growth, irrigated agriculture, groundwater over-abstraction and expanding urban and industrial demand add to the strain.

Capacity and supply strategies also differ among countries. Wealthier countries have expanded desalination and wastewater reuse, while conflict-affected and lower-income countries often struggle to maintain basic services. In Yemen, prolonged conflict, economic breakdown and disease outbreaks left more than 17.8 million people lacking access to healthcare and WASH services in 2026. Agriculture accounts for more than 80% of water withdrawals in the Near East and North Africa, so supply expansion alone cannot close the gap. Groundwater-abstraction controls, network-loss reduction and safe, fit-for-purpose reuse are just as important.

Water stress can aggravate existing political, economic and humanitarian pressures. Shared resources also make cooperation indispensable: about two-thirds of freshwater resources in the Arab region cross national borders, while only 27% of transboundary basin area was covered by operational cooperation arrangements. Durable water security begins with protecting and maintaining civilian WASH systems. It also requires allocation or tariff reforms developed transparently with local participation and protection of basic household needs.

Asia and Oceania: The Asia-Pacific region has made substantial but uneven progress in water security. 2.7 billion people have moved out of extreme water insecurity between 2013 and 2025, which entails rural and urban WASH, economic water security, ecosystem condition, and resilience to water-related disasters. 140 million people stopped practicing open defecation between 2022 and 2024, while only seven of 22 member States with sufficient data were on track to achieve universal basic hygiene by 2030. Gaps remain pronounced between urban and rural populations, higher- and lower-income countries, and continental states and Pacific small island developing States.

Climate and ecosystem pressures are changing the geography and timing of water risk. In 2025, destructive floods affected Pakistan, Sri Lanka and Viet Nam alongside severe drought in parts of West Asia; all 23 monitored glaciers in High-mountain Asia lost mass. Glacier retreat can alter seasonal runoff and increase hazards such as glacial lake outburst floods, but effects on water availability differ among basins and over time. In Pacific small island developing States, drought, groundwater over-abstraction and sea-level rise increase the risk of saltwater intrusion into limited freshwater aquifers. ESCAP found minimal net improvement in wetland condition in Asia between 2018 and 2024, while deterioration increased in the Pacific.

Seven of the world’s 10 largest groundwater-withdrawing countries are in Asia and the Pacific, making aquifer monitoring and abstraction governance a regional priority closely linked to agricultural and energy policy. Progress on safely treated domestic and industrial wastewater has been limited since 2015, and reporting remains incomplete. Of 30 ESCAP member States that share rivers, lakes or aquifers, 23 reported on transboundary cooperation in 2024, but only six had operational arrangements covering at least 90% of their transboundary surface-water basin area; cooperation over shared groundwater lagged further. Priorities are to expand safely managed WASH and wastewater treatment; reduce urban and irrigation losses; restore wetlands; protect freshwater aquifers in Pacific islands; strengthen multi-hazard early warning; and link infrastructure finance to maintenance, open data, affordability and inclusive basin governance.

Europe: Much of Europe has comparatively strong water-governance capacity, but hydrological exposure and implementation capacity remain uneven. Water stress affects about 20% of Europe’s territory and 30% of its population each year. 70% of European rivers had below-average annual flows in 2025, and storms and flooding continued to affect thousands of people. Low flows can constrain navigation, power-plant cooling and aquatic ecosystems, while floods and saltwater intrusion can disrupt water supplies and agriculture. Climate change intensifies these hazards, but land use, over-abstraction, ageing infrastructure and the loss of wetlands and floodplains shape how severely they translate into shortages or damage.

Basic WASH coverage is high by global standards but is not universal. More than 16 million people in the pan-European region still lack basic drinking-water services and 29 million lack basic sanitation. Within the EU, environmental water quality presents a wider systems challenge. Only 39.5% of assessed surface water bodies had good ecological status and 26.8% had good chemical status. Persistent pollutants contribute substantially to chemical-status failures, while nutrient and pesticide pollution, hydromorphological alteration, over-abstraction and incomplete wastewater collection and treatment remain important pressures.

Europe’s legal and cooperative framework includes the EU Water Framework and Floods Directives, the UNECE Water Convention and the Protocol on Water and Health. Yet the Commission concludes that the measures in current river basin plans will not achieve full Water Framework Directive compliance by 2027. The 2025 European Water Resilience Strategy seeks to restore and protect the water cycle, secure clean and affordable water, reduce leakage and improve EU water efficiency by 10% by 2030. Implementation requires basin-specific drought and flood plans, shared monitoring and early warning, transparent allocation rules during scarcity, pollution prevention at source, wastewater upgrades, demand management and reuse where appropriate, and restoration of natural water retention. Pricing and finance should support maintenance and efficient use while protecting basic household needs; transboundary cooperation should extend beyond rivers to shared aquifers and joint climate adaptation.

Latin America and the Caribbean: The region is water-rich in aggregate but highly unequal in where, when and to whom water is available. About 150 million people live in highly water-scarce areas. The regional water cycle is becoming more extreme, with longer dry spells and more intense wet events; in 2025, persistent drought affected parts of Mexico, the Caribbean and southern South America, while destructive floods affected Peru, Ecuador, Mexico and other countries. These conditions disrupt drinking-water systems, agriculture, hydropower, navigation and ecosystems, and interact with urban growth, land-use change, over-abstraction, degraded watersheds and insufficient storage.

Service progress remains uneven. In 2024, 140 million people, or 21.1% of the population, lacked safely managed drinking-water services and 324 million, or 48.8%, lacked safely managed sanitation. Safely managed drinking-water coverage ranged from 83.1% in South America to 58.9% in the Caribbean and 49.2% in Central America; the corresponding shares of wastewater safely treated and reused were 60.9%, 33.8% and 30.6%. Climate exposure compounds these gaps. The Andes serve as a water tower for about 90 million people, and accelerating glacier retreat is changing the timing and reliability of runoff while increasing both short-term hazards and longer-term supply risks. Caribbean small island developing States face additional exposure to drought, tropical cyclones, sea-level rise and the salinization of limited freshwater resources.

Water stress and pollution can sharpen competition among cities, agriculture, hydropower, mining and ecosystems. Implementation of integrated water resources management reached only 38% in South America, 39% in Central America and 40% in the Caribbean in 2023. The Regional Water Action Agenda and a 2025 initiative seeking to mobilize at least US$20 billion in climate-resilient investment by 2030 provide frameworks for acceleration. Their value will depend on whether investment produces maintained networks, functioning wastewater treatment, watershed and aquifer protection, and enforceable allocation arrangements that include social protection and meaningful participation by local and Indigenous communities.

North America: Water security in North America is shaped less by continental freshwater totals than by regional mismatches among supply, demand, infrastructure and governance. In the western United States and High Plains, warming, drought, shifts in snow accumulation and runoff, and intensive irrigation and municipal demand expose basins where groundwater is already declining. The 2025 U.S. national water-availability assessment, covering water years 2010–2020, found that low precipitation and limited surface-water storage often coincide with depressed groundwater levels, reinforcing the need to manage surface water and groundwater as connected systems. Canada’s large aggregate freshwater endowment is likewise uneven. Approximately 60% of its surface freshwater drains northward, away from the most populated regions. Water management must therefore be basin-specific.

Water-use patterns and infrastructure demands are also changing. U.S. estimates for 2020 identify crop irrigation, thermoelectric generation and public supply as the three largest withdrawal categories, with different regional profiles. Withdrawals for power-plant cooling can be large because much of the water is returned. EPA estimates $625 billion in drinking-water capital needs and separately reports $630.1 billion in clean-water infrastructure needs, including wastewater, conveyance and stormwater. Access and regulatory protection remain uneven. The Indian Health Service reported in 2026 that approximately 41,000 American Indian and Alaska Native homes lacked adequate sanitation facilities, including more than 4,300 without access to a safe water supply and/or waste-disposal services. Lead service-line replacement and controls for PFOA and PFOS remain major U.S. implementation priorities. As of 13 August 2026, 40 long-term drinking-water advisories remained active on public systems on reserves in 38 First Nations communities in Canada.

Governance across shared basins is decisive. The U.S. Department of the Interior issued a 2027–2036 Decision Framework for Lake Powell and Lake Mead. The framework establishes an adaptive process for successive operating periods. In Canada, the Canada Water Agency and Freshwater Action Plan, together with the Canada–United States Great Lakes Water Quality Agreement and the International Joint Commission, provide established coordination mechanisms. A critical regional uncertainty is whether infrastructure replacement, contaminant control, recognition of Indigenous rights and integrated surface-water and groundwater governance can keep pace with climate variability and long-lived infrastructure constraints.