Phase 1 of the programme was carried out during the period 2001-2005 and 26 projects were undertaken, covering a wide range of topics related to reduced flows, including low flows hydrology, groundwater, water temperatures, benthos, salmonid migration, population dynamics and catch statistics, remedial measures and visualisation of low flows. The projects were undertaken by universities, research institutes and by NVE itself. Programme highlights included the development of a programme for estimation of low flows in ungauged catchments, clarification of the importance of groundwater for river discharge and for the biota, assessment of the importance of discharge and other environmental variables for salmonid migration, the use of long-term catch statistics to evaluate the effects of river regulation on salmonids, the long-term effects of weirs as a remediation measures in regulated rivers and a manual for the visualisation of reduced flows.
In phase II of the programme (2007-2011) 31 projects, covering a wider range of relevant topics, have been initiated. Most of these are in progress, but two projects, an evaluation of the system for a trial period in connection with hydropower licences and an appraisal of the release of minimum flows based on catchment runoff have been completed. The former project concluded that trial periods were useful, but there must be clear time limits and close follow-up from both government agencies and the developer. The latter project chose two pilot regulated rivers in an attempt to develop a flow regime based on catchment runoff, measured via a gauging station in an unregulated part of the catchment. This would then be coupled to regulated releases and incorporated into a discharge regime based on other user interests. A possible control system was also proposed.
One important focus area in phase II is the environmental effects of small hydro, in particular possible effects on landscape and elements of biodiversity, including lichens, mosses, benthos, fish and birds (the Dipper Cinclus cinclus). There is the need for increased knowledge in this area when assessing environmental impacts in connection with the licensing process. Another relatively new form of hydropower in Norway is hydropeaking. Here again there is a clear need for improved knowledge of the environmental impacts, in particular erosion and sedimentation processes.
The impact of hydropower development on biodiversity and endangered plant and animal species is a crucial aspect in the licensing process and reviews are being undertaken for several taxa, including the freshwater pearl mussel (Margaritafera margaritafera) and the European eel (Anguilla anguilla).
A number of projects are addressing mitigation measures in regulated rivers and hydropower reservoirs. These include a general evaluation of potential mitigation measures in impacted catchments, as well as follow-up studies on earlier mitigation measures such as weirs. Temperature changes in reservoirs and regulated rivers and ways to lessen such impacts are also being studied. Further topics include aids to the management of the licensing process such as the use and suitability of models as well as the standardisation of environmental impact assessments.
The programme has also provided additional funding to a number of existing projects relevant to the objectives of the programme. These include the research programmes, Hydrofish, EnviDorr and Bioclass-Fresh that focus on the management of fish populations in reservoirs and regulated rivers. Funding has also been allocated to the management of the noxious aquatic weed, Juncus bulbosus, studies to develop suitable native species for revegetating construction sites in mountain areas and investigations on the ecology of a voracious blood sucking blackfly, Simulium truncatum, whose abundance appears to depend on river levels.
A wide range of topics are being addressed in phase II of the Norwegian Environmental Flows Programme and it is crucial that this new knowledge reaches those involved in the licensing process. During the course of the phase II several management seminars are being held in addition to a national conference at the end of the Programme.