Conference Agenda

Access to safe drinking water is a fundamental human right, yet more than two billion people worldwide lack it, increasing the prevalence of waterborne diseases, particularly in low-income countries. Addressing this challenge requires cost-effective policies that enhance water supply while mitigating the impacts of climate shocks. This study evaluates the effectiveness of a large-scale, decentralized adaptation program designed to increase the resilience of low-income households in Brazil’s Semiarid region to recurrent droughts. The Cisterns Program constructs low-cost rainwater harvesting systems, now serving over 25% of the region’s population, primarily in remote rural areas. The analysis finds that the program significantly reduces acute diarrheal infections (ADI) and other waterborne diseases, lowering cases by 168 per 100,000 residents — a 32% decline in hospitalizations and ambulatory care. Moreover, the program fully offsets the negative health effects of drought shocks, underscoring its role in strengthening community resilience. The analysis of potential mechanisms suggest that education enhances program effectiveness, likely by improving compliance with usage guidelines and increasing agency over water resources. These findings remain robust across multiple model specifications and placebo tests, highlighting the potential of low-cost interventions as viable climate adaptation strategies, particularly in regions where large infrastructure projects are impractical.