Based on a rigorous protocol and companion evidence gap map, our systematic review conducts meta-analyses of water sector interventions in four areas: built infrastructure, nature-based options, institutional interventions, and financial/market mechanisms. The results suggest that water-efficient irrigation systems and ecosystem-based watershed management stand out as valuable tools for enhancing adaptive capacity, warranting specific attention. The complexity and diversity of water resources necessitate a nuanced analysis of specific concerns, considering economic, social, and environmental challenges.