The great challenge that faces all the Latin American countries is the water supply in suitable amount and quality for all its inhabitants. The conceptual plan in the CYTED - XVII is to emphasize the knowledge of the existing link between the water use and ecosystems. The scientific knowledge is the base for an integrated management of a short resource like the water. The countries of Latin America constitute a vast historical and cultural unit, that involves a great extension and diversity of natural resources and evironments. The water is part of these, but also it is a part of the culture of the towns. Therefore the CYTED - XVII wants to make a contribution from the basic research to the management systems.