The increasing human population and degradation of biological integrity of ecosystems has been expressed, to a great extent, as a decline in water resources, the most critical factor to achieve sustainable development. This is because overexploitation and degradation of the biotic structure alters ecosystem processes to the point at which the ecosystem ability to provide desired resources is seriously diminished. The progress in ecology during recent years has created a background for integration of ecology and hydrology. UNESCO, under the International Hydrological Programme IHP-V, has initiated and provided a framework for such an interdisciplinary effort. During the programme, the conceptual background and principles of the surficial processes of ecohydrology were defined: first, by integration and quantification of biological and hydrological processes at the basin scale; second, by the enhancement of basin ecosystem absorbing capacity against human impact; and third, by using ecosystem properties as a management tool. Those principles are targeted, not only to eliminate threats, but also to amplify the opportunities for sustainable development as far as the control and regulation of nutrients and water cycling at the basin scale become possible. According to Popper's philosophy, the predictive planning of the future cannot be generated by extrapolating from recently used solutions. The integration of environmental sciences should create not only new scientific disciplines, but also a new solution which can face new challenges-sustainable management of the biogeosphere.