The project 'LiLa Living Lahn' looks at positive and negative effects of selected courses of action for the development of the river Lahn on ecosystem services (ES) and evaluates them economically, if possible. Thereby, it should support decisions on the future development and maintenance of the Lahn on the basis of the Lahn concept, which is currently being developed. Conceptual variants in dealing with the barrages located on the Lahn provide different courses of action. In addition to impacts on the adjacent floodplain areas, they also affect the particularly relevant uses of the Lahn's natural capital, i.e. recreational navigation and hydropower.
The effects of the alternative courses of action on the relevant ecosystem services are mapped as broadly as possible. The knowledge from different disciplines is brought together and considered in an integrative manner. The selection of the included ecosystem services should, as far as possible, reflect all relevant use interests and, where applicable, interactions. Transparent information on the social advantages and disadvantages of the courses of action (and as far as possible: on economic costs and benefits) is provided and thus a broad and technically sound basis for consideration and decision-making. Different stakeholders can jointly discuss the various courses of action on that basis. The focus in the selection of methods for the study is on the provision of ES which are described by various indicators. ES for which there is insufficient data available for assessment are either excluded for good reason or assessed by experts. Existing indicators from the BMBF project RESI are adapted or developed further. All considered ES are evaluated verbally-argumentatively as well as quantitatively for different variants. The IÖW contributes the economic assessment of selected ES with price- and cost-based assessment methods.