Today 748 million people around the world still have no clean water to drink. World Water Day is marked on March 22 every year. It’s a United Nations day to celebrate water, make a difference for the members of the global population who suffer from water-related issues, and prepare for how we manage water in the future. In 2015, the theme for World Water Day is 'Water and Sustainable Development', focusing on how water is at the core of sustainable development. Water resources, and the range of services they provide, underpin poverty reduction, economic growth and environmental sustainability.