Sustainable watershed management: an international multi-watershed case study.

Global freshwater resources are being increasingly polluted and depleted, threatening sustainable development and human and ecosystem health. Utilizing case studies from 4 different watersheds in the United States, Japan, Switzerland, and Brazil, this paper identifies the most relevant sustainability deficits and derives general vectors for more sustainable water management. As a consequence of the demographic and economic developments experienced in the last few decades, each watershed has suffered declines in water quality, streamflow and biotic resources. However, the extent and the cultural perception of these water-related problems vary substantially in the different watersheds, leading to specific water-management strategies. In industrialized countries, exemplified by the US, Switzerland, and Japan, these strategies have primarily consisted of finance- and energy-intensive technologies, allowing these countries to meet water requirements while minimizing human health risks. But, from a sustainability point of view, such strategies, relying on limited natural resources, are not long-term solutions. For newly industrialized countries such as Brazil, expensive technologies for water management are often not economically feasible, thus limiting the extent to which newly industrialized and developing countries can utilize the expertise offered by the industrialized world. Sustainable water management has to be achieved by a common learning process involving industrialized, newly industrialized, and developing countries, following general sustainability guidelines as exemplified in this paper.