Förstudue till en Miljökonsekvensbeskrivning angående rivning av vattenkraftesdammar : Samt simulering av av vattenflöden

Sammanfattning: On the basis of a legislative amendment that came into force in January 2019, which states that all dams will have to achieve modern environmental conditions, all hydropower dams in  Sweden will need to be licensed. Arvika Kraft has two regulating dams Kivilamp and Rolamp  which they do not believe will achieve the modern environmental conditions. Arvika Kraft  therefore wants to have a feasibility study for an environmental impact assessment carried out  in order to be able to study possible measures for the dams. They wanted a potential  demolition of the two regulatory ponds to be studied in this preliminary study. In an environmental impact statement, several alternatives are to be studied, and in this  feasibility study, the zero alternative is to maintain the regulating dams as they are today, the  main alternative being to demolish the two damsand the third alternative that was chosen to be  studied is the introduction of turbines in the dams along with the construction of fish roads  passing them.  In the report, a literature study is carried out to deepen the knowledge in the area, a modeling of the three alternatives to be able to study how the energy production of the power dam  downstream as Kivilamp and Rolamp acts as a regulator are affected, and finally the actual  collection of information for the preliminary study of the environmental impact assessment.  The result of the study shows that the zero alternatives contribute to regulation that increases energy production of the power dam downstream but that the two ponds Kivilamp and  Rolamp are migratory obstacles to the aquatic animals. The problem with the zero alternative  also remains that there is a great risk that the dams do not meet the modern environmental  goals at present.  The result of the main alternative shows that, according to the models, energy production would be lowered in the event of a demolition of the two regulating dams. The water flow, on  the other hand, would be more natural and the two migratory obstacles would disappear for  the aquatic animals. However, the flow would continue to be dammed downstream, which  would mean that only a small section of the total flow path would be free from migratory  obstacles.  For the third option studied, the result was an increased energy production but not as high as expected because the two regulating dams had a relatively low drop height compared to the  power dam downstream and that the flow was somewhat lower for Kivilamp and Rolamp in  comparison. By way of the constructed fishing roads, on the other hand, free movement would be facilitated and this would be a positive change for the aquatic animals.  The conclusion was that the best alternative where energy production was weighed together with an improved environment for the aquatic animals was the third option. However, this can  be costly and difficult to implement in practice and in such cases the best thing would be to  demolish the regulating dams.