Water flows as a prerequisite through every one of the Sustainable Development Goals (SDGs), especially those on food security, healthy lives, energy, sustainable cities, sustainable consumption and production, and marine and terrestrial ecosystems. SDG 6 specifically reflects the critical importance of water in its own right, ensuring availability and sustainable management of water and sanitation for all. The Policy Perspectives set out essential facts about the economic case for water-related investment and the financing gap. It charts a series of actions to better value water and ultimately facilitate investment at a scale commensurate with the commitments of the global community.