Interest in water accounting is based on the premise that ‘We cannot plan and manage what we do not measure’ – a statement that few would disagree with. Society needs more accurate information and answers to the key questions about water supply and demand. More data are needed but simply doing water measurements and assessments is not enough. Water accounting per se is of little use. But as a tool for understanding and resolving water problems and supporting water management, it is invaluable. Water accounting alone cannot resolve the problems of water governance and managing water resources, but it can go a long way to improving and reforming governance and providing the information needed to support sound decision-making.