Hjartdøla and Heddøla rivers are home to the red-listed species freshwater pearl mussel and eel, as well as prioritised freshwater organisms such as lake trout and European whitefish. Reduced flow will change the growth and living conditions for fish and freshwater pearl mussels in Hjartdøla. The negative impact is expected to be greatest during the winter due to low flow and freezing of shallow areas. The assessment found that this would have a medium negative impact for fish and benthos in Hjartdøla river. The effects of the measures taken in the Skogsåa watercourse are related to a reduction in the spawning area for fish and benthos, and are assessed as having a low negative impact.
The side streams Grovaråa, Vesleåa, Kvitåa, Uppstigåa and Skorva are of less importance to the fish population, and the degree of impact has been assessed as low negative. In Vesleåa/Kjempa, a slight deterioration in living conditions for trout and brook lamprey is expected, and the degree of impact is therefore assessed as low to medium. The impact in Heddøla is linked to changes in the water temperature downstream of the power plant outlet. The impact of this is assessed as medium negative.
The building of Sauland Power Plant will primarily impact wildlife linked to the waterways and the actual affected area. The main impact of the development will be on species such as the white-throated dipper, grey wagtail, common goldeneye duck and beaver. For these species, reduced populations must be expected over time. For species that maintain their areas/territories, reduced reproduction may result. Other wildlife in the area will primarily be affected during the construction phase, without this having noticeable effects on the local populations. The development is not expected to have a significant effect on rare or endangered species. As a whole, the development will impact few areas of value in a broader context. The impact on wildlife within the area of influence will be within the range of small to medium negative.
Sauland Power Plant has been assessed as having a high negative impact on Skogsåa river and the side streams Vesleåa/Kjempa and Skorva. The assessments are related to findings of the red-listed species alder silk moss, drooping woodreed, wolf’s bane, as well as red-listed fungus species and endangered habitat types. The impact on vegetation along the Hjartdøla river is assessed as medium negative.
The assessments in the report Fagrapport Flora are based partly on claims of an expected change in the local climate, which have not been supported by the report Fagrapport Lokalklima. The Fagrapport Flora report warns of negative impact on habitat types such as pollarded or coppiced deciduous woodlands and diverse temperate deciduous forest. The developer therefore believes the assessed degree of impact on the vegetation in certain places to be too high.