Scientific Research for Defining the Sustainable Use of Hydropower

The concept of green hydropower needs an evaluation procedure for the ecological upgrading of hydropower plants based on scientific criteria [1]. For the planning and evaluation of riverrestoration programs, concepts like “ecosystem integrity” or “river health” have been proposed and empirically tested. Computer programs have been developed, which allow the testing of alternative restoration concepts and a quantification of hydrological regimes for minimal flow requirements. Such generalized approaches are needed to focus a multidisciplinary effort to quantify the detrimental ecological effects of hydropower use on a local level and to determine promising upgrading pathways. In this paper we discuss the experience of a large-scale pilot study of a hydropower plant in the Southern Alps. The study was designed as a test site for the evaluation procedure for green hydropower. It should allow at the same time to gain scientific insight into the network of ecosystem processes affected by hydropower use. Three main conclusions can be drawn from the experiences so far: