Dialog between designers of flood mitigation techniques and biologists is essential to minimize ecological effects on rivers. For a successful cooperation, a tool is needed to highlight the relationships between hydrology, geomorphologic contexts, habitats, and biodiversity. Riverscapes, ranked according to their ecological potential, can convey information about those relationships. On a test-case, a mountain river of Polish Lower-Silesia, we defined four types and four sub-types of riverscapes, based on the stream-bed structure, with mention of the associated biodiversity. Then, we listed dry dams design constraints for the upstream part, the dam itself, and the dowstream area. For each stretch, a riverscape type/sub-type was set as the best attainable objective regarding these constraints. Riverscape types can then be the support to discuss further adaptations. This study sets up the approach, and will be improved in the future in more complex contexts.