NEWS New research from Umeå University shows that it is possible to implement measures that provide more environmentally friendly flows in regulated rivers with only small losses in hydropower production. The study is published in the scientific journal Water Resources Research.
Byssjan, a tributary of the Ume River.
ImageÅsa WidénSweden is facing a national review of all hydropower permits where greater demands for environmental considerations must be made.
Flows and water levels change when constructing hydropower plants and dams, which in turn changes the conditions and living conditions for organisms in the regulated watercourse and also the power plants prevent fish migration. Water flows and water levels change rapidly, so-called short-term regulation, and cause stress and disturbances for the species of the watercourses.
Through ecological regulation of the flow, some of the ecosystems of the regulated watercourses can be recreated and biological diversity preserved. In the current article, the research team from Umeå University has carried out field studies in the Ume River and presents 28 scenarios with ecological regulation with environmental benefits and impact on electricity production.
Åsa Widén currently has a postdoctoral position at the sedish University of agricultural Sciences, SLU.
ImagePrivat“We show that the hydropower plants in the Ume River can be adapted to the environment with relatively small losses of electricity or even without impact on production,” says lead author Åsa Widén, who recently completed her doctorate at the Department of Ecology and Environmental Sciences at Umeå University.
She further explains that it is unusual to have results from environmental measures where both costs and environmental benefits are quantified. As an example, a zero discharge ban (requirement of a minimum constant flow through the power stations) combined with spillage of 1–12 percent of the average annual flow to dry furrows would result in a loss of 2.1 percent of annual electricity production. If fishways were added, the loss would increase to 3.1 percent per year. The results do not include the impact on balancing and regulating power.
According to Åsa Widén, the research results are important to be able to preserve biological diversity in regulated waterways and relevant because Sweden is facing a national review of all hydropower permits where greater demands for environmental considerations must be made.
Åsa Widen has carried out the study together with a team of researchers: Roland Jansson, Birgitta Malm-Renöfält, Erik Degerman and Dag Wisaeus.
Widén, Å., Malm Renöfält, B., Degerman, E., Wisaeus, D., och Jansson, R.: Environmental flow scenarios for a regulated river system: projecting catchment-wide ecosystem benefits and consequences for hydroelectric production. Water Resources Research. Volume 58. 1:2022.
