The Volta basin in West Africa is situated mainly in Ghana and Burkina Faso. An overview of the hydrology of the basin and present trends in water demands is presented. The GLOWA-Volta research project is introduced. The scientific challenge of the project is to quantitatively link models from all relevant disciplines to create a decision support system for the Volta basin. The paper concludes by highlighting the institutional links which may favour the acceptance of science-based policies.