Impact of hydropower on river habitats studied by University of Hull team

Researchers at the University of Hull’s International Fisheries Institute have supported a European study into the impact of hydroelectric power plants on fish populations.

The University team, comprising of Prof. Ian Cowx and Dr Richard Noble, worked with experts across the continent to develop new methods and technologies to assess and mitigate how hydropower is impacting our environment.

Hydropower is one of the most important and widely used renewable energy sources. Arguably its main advantage is it is far less weather-dependent than wind or solar power.

However, hydropower plants involve major interventions with the natural world, such as the damming of rivers, altering aquatic habitats, and impacting fish mortality through turbines, spillways or screens.

The project, titled FIThydro, developed new solutions, assessment methods and technologies such as a fish population hazard index, simulations for fish migration and an open-access decision support tool for hydropower planning.

Dr Richard Noble said “The new FIThydro decision support tool not only provides a much-needed integrated and transferable project scoping tool.

“It also provides decision-makers a gateway to the new knowledge generated by the FIThydro project, enabling improved protection for fish and greener hydropower production.”

In the four-year EU project FIThydro (Fishfriendly Innovation Technologies for Hydropower), 26 European research institutions and companies studied the effects of hydropower plants on ecosystems - in particular fish - at 17 test sites in eight countries.

At each of the test sites, the team initially studied existing methods and technologies used to assess the impact and mitigation measures at hydropower plants.

The second part of the project explored possible measures to retrofit hydropower plants – as well as new decision-making tools for hydropower operators and planners.

Prof. Peter Rutschmann, from the Technical University of Munich and coordinator of the FIThydro project, said: "These decisions are highly complex.

"The hydropower plant and the site-specific conditions play a role. But it is also necessary to comply with regulatory standards on the national and EU level. And for the operators it is of course important for the measures to be effective and cost-efficient.

"It was important to us that the test sites reflect the diverse geographical, hydromorphological and climate conditions so that our results would be applicable to a wide range of hydropower plants in Europe.”

Reducing the negative ecological effects of hydropower plants is one of the objectives of the European Water Framework Directive.

However, older hydropower plants in particular often fail to meet these new requirements and need to be retrofitted before their certification can be renewed.

Prof. Ian Cowx and Dr Richard Noble, at the University of Hull International Fisheries Institute, devised a risk-based approach to support evidence-based mitigation planning and decision-making in a project planning framework.

This framework was implemented, together with IT specialists at TUM, into an open-access web tool to support hydropower planning across Europe in relation to the mitigation of the impacts of hydropower plants on fish.

The University’s International Fisheries Institute also helped develop a Fish Population Hazard Index for European fish species, which quantifies the risk posed by hydropower use to fish populations.

Working alongside the Leibniz-Institute of Freshwater Ecology and Inland Fisheries and Technical University of Munich, the team collected data such as fish lifespan, reproduction rates and migration behaviour as well as habitat requirements such as temperature and flow rate of the stream.

Based on these data, tolerance thresholds were derived for individual species that are specific to the impacts of hydropower plants. These can then be used by hydropower operators for the assessment and planning of mitigation measures.