WFD-compliant assessment of the effects of hydropower plants on riverine fish assemblages

The objective of the project "Fish ecological assessment of river power plants - Extension of the MIRR Case Study Traisen river" is to analyse different scenarios for the improvement of the ecological status of the middle and lower Traisen river in Lower Austria (residual flow, morphological restauration, different types of power plants). In accordance with the WFD measures have to be adequate to achieve the good ecological status. Based on the requirements of the WFD a designation test for Heavily Modified Water Bodies must be performed and the good ecological potential must be defined if necessary. Also, measures to achieve the good ecological potential must be identified. A second goal of the project is to define basic criteria for ecologically optimised river power plants. Basis are fishecological surveys which were performed on several rivers in Lower Austria.