EFHI can assess single- and multi-turbine set-ups in a variety of HPPs and streams. It uses an optimized number of compa rably easily obtainable input parameters, while all other relevant parameters resulting from their complex interactions are modeled or approximated from literature and empirical studies from similar systems. Regional biogeography and conservation concerns are specifically considered by the selection of target species and account for rehabilitation planning, protection requirements and other management de- cisions. The EFHI has implemented an inventory of 168 fish species native or established in European waters classified by sensitivity against mortality and other relevant traits, and it supports mitigation planning by enabling the selection of potential mitigation measures and measure combinations and assessing their effect on the hazard score. The EFHI provides a robust, evidence-based, broadly applicable, and transparent screening tool for systematic risk assessment of HPPs for fishes and as such, we expect it to be highly useful to a wide range of stakeholders.