Background
Environmental conditions in many regulated rivers deviate substantially from their natural state. The production of salmon is also affected by these changes in their habitat. Today, we know a lot about how various environmental factors affect the production of salmon – both for the better and the worse. In rivers regulated for hydropower purposes, the licence-holder can affect the environmental conditions and help to provide better conditions for the production of salmon. Hydropower production licences often contain terms and conditions which were laid down at a time when our knowledge of the environmental factors affecting the salmon was not as good as it is today. Both we and the authorities are interested in developing a more dynamic river management regime and making more efficient use of existing hydropower schemes.

Implementation
This is the first time specialists from top research establishments in the fields of salmon biology and power generation have been brought together in one project in Norway. At the same time, the project has established links with internationally recognised experts from Sweden, the USA and Canada. The project is entitled “Increased power and salmon production with Environmentally Designed Operation of Regulated Rivers” (EnviDORR). It is defined as a user-run competence-raising project (KMB) under the RENERGI programme (Clean Energy for the Future) and will be jointly funded by the Norwegian Electricity Industry Association (EBL), Statkraft, Agder Energi, BKK and the Directorate for Nature Management. 

The project aims to exploit existing knowledge of salmon biology, gather new biological data and conduct experiments under controlled conditions. By combining new biological models and models for hydropower production, we can develop ways of operating hydropower plants so that we produce as much electricity and as much salmon as possible. This method will allow us to investigate the potential for environmentally designed river management systems and for increased value creation with regard to both electricity and salmon. 

The project is based on the premise that regulation allows the river’s physical attributes, eg water flow and temperature to be controlled. Physical factors which affect the production of salmon can therefore be enhanced or moderated, depending on whether their impact is positive or negative.

Results

• To develop strategies for operating hydropower plants in regulated rivers which optimise the balance between electricity and salmon production
• To develop criteria for how hydropower plants can be operated or expanded in a more environment-friendly way
• To develop quantitative models which describe the links between physical conditions which are affected by river regulation and biological bottlenecks for the production of salmon