With "integrated water resources management" (IWRM) the current buzzword in international circles, the real question is: how to operationalise a truly multidisciplinary approach to the effective management of shared watercourses. Based largely on the actual experience of HELP (Hydrology for the Environment, Life and Policy), the overall aim of the book is to produce a series of case studies from around the world (from the Aral Sea to Zimbabwe) that demonstrate how the "gaps" between hydrology, water law and management are actually bridged in practice. Is hydrological data relevant and used in the formulation of national and international water law and policy? Cases cited include examples of where this has happened and been successful or unsuccessful and where this has not happened and led to problems. This will act as a guide to how future water laws and polices can be made more effective via the use of accurate and up to date hydrological information.