SJE Ecohydraulic Engineering GmbH celebrates its 20th anniversary in 2021. Founded in 2001, the company works at the interface between river hydraulics and river ecology. Since then, SJE has been involved in various research projects, while at the same time developing new technologies, in particular modelling tools for eco-hydraulic studies, and applying these new tools to environmental impact assessment, especially with regard to hydropower plants.

In Hydro4U, SJE and its associated partner KJ Consult are responsible for the planning of sustainable small-scale hydropower (SHP) at several demonstration and planning sites. The design and operation strategies of the planned hydropower plant (HPP) will be optimised in order to minimise environmental impacts. Main aspects considered are e.g.

• riverine habitats upstream and downstream of the HPP sites and potential compensatory measures to support river ecology,
• environmental flows to be released to ensure good ecological conditions for aquatic organisms in all seasons,
• the optimised operation of turbines to prevent rapid flow changes and
• the design of upstream and downstream migration facilities integrating telemetry studies and innovative modelling (using tools developed in the H2020 project FIThydro).

To reach the goal of implementing environmentally friendly hydropower, SJE closely cooperates with local experts (Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, Uzbekistan) as well as with renowned European partners (BOKU Vienna, Austria and EVINBO Brussels, Belgium) integrating knowledge in fish ecology, water quality, sampling and tracking technologies, environmental hydraulics and hydrology. The fish species caught by the local fish ecology expert in the area of the potential HPP sites that could serve as indicators for river ecology are snow trout (Schizothorax sp., first picture) and a genus of stone loach (Nemacheilus sp., second picture). Their habitat requirements serve as input for habitat investigations, carried out using the SJE software CASiMiR (www.casimir-software.de) for environmental flow setting.

Authors: Matthias Schneider, SJE Ecohydraulic Engineering GmbH

Photo credits: Bakhtiyor Karimov, Tashkent Institute of Irrigation and Agricultural Mechanization Engineers