In the recent decades, due to improper management of river ecosystems adverse effects occurred in riverbeds hydromorphology. Increased water retention and use of hydroelectric rivers, which entails the construction of new hydro power plants requires a new look at the continuity of the river corridor. According to the RDW "heavily modified water body means a body of sur-face water, the nature of which has been significantly altered as a result of physical alterations by human [...]"[Dyrektywa 2000/60/WE]. The heavily modified water bodies should aim to achieve good ecological potential of waters. It is to be achieved through the construction or reconstruction of water structures to ensure efficient migration and living conditions for fish and other aquatic organisms.The aim of this study is to determine the construction limits of rock fish-ladders that meet the biological criteria of fish in the Skawa river. Laboratory measurements were carried out on the physical model of rock fishladder. The re-sults of laboratory measurement were used to calculate hydraulic condition within fishladder to determine biological stability of fishes: discharge, velocity of water, water depth and energy dissipation. ...
Flood risk management and river training made with use of bed stabilization techniques followed by straitening and shortening of river corridors caused increase of the fall. As the effect hydrotechnical structures emerged with the aim of utilisation of water energy by damming the water movement. Such a structures break a river's continuity and fish migrations upwards the river is impossible. Regaining river's connectivity requires use of additional hydrotechnical solutions having purpose of making possible for fish to navigate obstacle in their migration up rivers and streams. Over the time development of the solutions in the field of fish migrations leaded to variety of constructions among them only some number really functional. The necessary compromise is needed to met all the expectations for any type of the fish pass, among them minimal and maximal water velocities, high energy losses, geometrical limitations especially considering the fact their interconnected.The paper proposes separation of particular elements generating energy losses in water movement described by energy dissipation formulae. Measurements were taken on an existing rock ramp fish way on the Tuszymka River in the Kamionka settlement and consisted of fish way geometry and water velocities. Water velocities measurements location concentrated along the places with maximal ...
