Hydrometric information is fundamental to the planning, operation and management of water resources and flood defence. The data network is greatly valued by those who use it, yet assignment of a monetary or economic value is problematic. Data managers are often frustrated by the need to continue to justify a network. The paper focuses on the uses of data within the Environment Agency of the UK, explores the difficulties in assigning a value to the data and attempts to review the value ascribed to such data by drawing on some UK and wider examples.