Hydropower is a very efficient source of energy, however there will always be questions related to the effect it has on the fauna in the rivers. In EnviDORR salmon scientists, hydrologists, hydropower engineers, industry and management join forces to develop optimal solutions to increase both salmon and hydropower production in regulated rivers.
The main focus for mitigation in regulated rivers used to be to mimic natural flow conditions. EnviDORR focuses on enhancing positive and reducing negative effects of river regulation, while maintaining or increasing the power production. To design optimal solutions, it is vital to expand our knowledge on the effects of environmental variables on the different life stages of salmon.
Methods for restoration and improvement of habitat conditions without loss of power production have been used in a few Norwegian rivers. Models show that adaptive hydropower operation will ensure successful spawning, egg (preventing dewatering) and juvenile survival (residual flow patterns). We are also developing strategies to prevent turbine smolt mortality, and in the River Mandalselva strobe lights and optimal diversion of water in the bypass section has increased smolt survival from 10 % in 2003 to 64 % in 2008. Upstream migration solutions are also a major task in the project.