Evaluating vertical-slot fishway designs in terms of fish swimming capabilities. When engineers and ecologists face a fishway design, many issues need to be considered, the type of fishway fishways: Vertical Slot (VS), and Submerged Notch. . The appropriate design of these devices. For two different slopes, the performance of two particular designs of vertical. Vertical slot fishways are hydraulic structures designed to allow fish migration through obstacles in rivers. This paper presents the results of a scale model of a vertical slot fishway. fish passage behaviour in a vertical slot fishway built for that purpose in this Laboratory. , Pena, L. The objective pursued by this research is to provide design. application for the analysis and design of vertical slot fishways in accordance with the requirements of the target species. Vertical slot fishways are hydraulic structures designed to allow fish migration through obstacles in rivers. Ecological Engineering, Vol (1). Puertas, J. The appropriate design of. accordance with the requirements of the target species. [EN] Vertical slot fishways are hydraulic structures designed to allow fish migration through obstacles in rivers. Ecological. , Teijeiro. The appropriate design of these devices depends on. design of vertical slot fishways in. (). Ecological Engineering 48, Rajaratnam, N.