Quantify the scale of water infrastructure failure, assess climate-driven stress on freshwater systems, and evaluate the economic and health consequences of persistent water inequality.

Integration of WHO/UNICEF JMP data on water access, World Bank infrastructure database, USGS freshwater availability projections, and hydrological models from the Global Water Institute. Cross-referenced with cardiovascular and waterborne disease epidemiology from the Global Burden of Disease Study.

5 billion lack safely managed sanitation. Water stress affects 4 billion people — more than half the global population — for at least 1 month per year. In the next 20 years, half the world's population will live in water-scarce areas for at least 1 month annually. Water-related diseases kill 829,000 people per year — more than malaria, TB, and HIV combined.

5-1% per year against a need for 2-3% per year to maintain service. Climate change is accelerating both water scarcity in some regions and flooding in others — the infrastructure gap is widening faster than it can be closed.