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In the first decades of the 20th century drainage of wetlands and canalization of rivers were a big issue in Middle Europe to improve flood control and agriculture in the floodplains and riparian zones.The results were very positive for land users, but for the ecological situation of our river landscapes they are a disaster.The rivers got straightened and dammed, water was taken out in channels for irrigation or for hydropower.The longitudinal continuity of the rivers were cut in sections, interrupting the migration of fishes.Point and nonpoint pollution reduced the ecological quality of the river andthe water quality.Habitats for plants and animals got lost.The recreational value of such rivers was reduced.In the last decades of the 20th century river restoration projects were started· to improve flood control· to improve ecology of the river, the riparian zones and the and floodplain and· to enhance the beauty of the landscapes, especially their recreational value.