Flowing through every part of our economy, water is a fundamental necessity for lives and livelihoods. Access to safe, resilient water supplies is essential to economic prosperity, health, development and environmental sustainability. The adoption of the Sustainable Development Goals (SDGs) put water security under the international spotlight, but if SDG6 – the goal to ensure the availability and sustainable management of water and sanitation – is to be achieved, we need robust data on the current landscape and what needs to change. This World Water Week, CDP examines how disclosure is accelerating progress towards a water-secure future.