Under the Federal Water Act, measures must be undertaken at hydroelectric plants to protect fish from turbines and improve the descent of migratory species of fish. According to the Research Laboratory and Inspection Authority for Environmental Engineering and Water Engineering (“Versuchsanstalt und Prüfstelle für Umwelttechnik und Wasserbau”) at the University of Kassel this can occur reliably only with finely-calibrated mechanical barriers, so-called “fine screen systems”.
These barriers, while protecting the fish from the turbines, prevent them from passing the hydroelectric plant. This is dealt with through technical construction features which open a safe and easily found alternative migration “corridor” for the fish. Traditional solutions based on the concept of “guiding the fish” have not produced convincing results, due to high costs and a failure to produce discernible improvements in efficiency.
As an alternative, the Research Laboratory for Water Engineering (Univ. of Kassel) is investigating the possibility of a “lifting-trough” for fish which would function based on the principle of “fish collection” and promises decisive improvements in migrational fish descent. This “fish lift” combines the tasks of screen cleaning and regulating fish descent in one system.
