Abstract
The authors designed a new site-adapted fish passage system for upstream and downstream migration of small and large fish on the urban sector of the Bistriţa River. The longitudinal connectivity of this lotic system is interrupted by numerous transversal hydrotechnical works (weirs). This proposed system was designed to facilitate fish migration, promote fish recolonization of upstream and downstream habitats, allow the expansion of fish range, and increase spawning potential. All components of the proposed system are attached to a concrete girder located to the right stream bank, except a glass basin that is submerged in the riverbed. The positioning of the system in this girder ensures its resistance to high water events, while offering safe passage for fish in both directions.