Vattenfall aB GeneRatIOn nORDIC CeRtIfIeD enVIROnmental ...

4 Additional environmental information
River Indalsälven: Bergeforsen (quality level C2)
Historical data from the area around the power station at Bergeforsen is insufficient, and a
characterization key has been applied to before exploitation conditions. Characterisation
of after exploitation conditions is based on data from fieldwork and literature. Streaming
water downstream the power station, 6 %, is characterised as rare biotope because this
stretch harbours rich fish fauna and various key elements such as sand banks. No critical
biotope is identified after exploitation, and the share of technotope is app. 55 %.
River Ångermanälven: Stalon (quality level C2)
The power station Stalon is located in the upper section of the river Ångermanälven, more
specifically in the branch named Åseleälven. The station is underground and utilizes the
height of fall of 199 meters between the lakes Kultsjön and Malgomaj.
Historical data from the area around the power station at Stalon is insufficient, and a characterisation
key has been applied to before exploitation conditions. Characterisation of after exploitation
conditions is based on data from fieldwork and literature. Streaming water is characterised
as rare biotope because of the trout population. The small lakes along river Kultsjöån, and
the reservoir Kultsjön harbour vigorous populations of trout and char. More than 70 % of the
exploited area is characterised as rare biotopes and the remainder as technotope.
4.2.1.3 Södra Norrland
Älvkarleby power station in river Dalälven has been selected in the river region Södra Norrland
and it occupies app. 0,3 % of the total land and water area that is exploited by the 14 selected
stations, whereas it contributes app. 5,3 % to average annual generation.
River Dalälven: Älvkarleby (quality level C2)
Historical data from the area around the power station at Älvkarleby is insufficient. It was was
built in the beginning of the 20th century. Aerial photographs and biotope inventories from
the before exploitation period are nonexistent, and a characterisation key has been applied.
Characterisation of after exploitation conditions is based on biological data from fieldwork
and literature. Kungsådran represents 3 % of the area and harbours migrating salmon, and is
characterised as critical biotope. Vattenfall has implemented extensive activities to improve
conditions for fish. Recreational fishing waters in Älvkarleby are among the best in Sweden
for salmon and trout. No rare biotope is identified after exploitation, and 90 % is registered
as general biotope.
4.2.1.4 Västsverige
In the river region Västsverige the stations Olidan/Hojum in the river Göta älv have been
studied. The two stations occupy 0,5 % of the total land and water area that is exploited by
the 14 selected stations and they contribute app. 13 % to the annual average generation.
Göta älv: Olidan/Hojum (quality level C2)
Historical data from the area around the power stations at Olidan/Hojum is insufficient.
The first station was built in the beginning of the 20th century. Old maps reveal that the
area was home to industrial operations, which caused extensive technotopes in the before
exploitation period. Aerial photographs and inventories from the before exploitation
period are nonexistent, and a characterisation key has been applied to before exploitation
conditions. Characterisation of after exploitation conditions is based on data from
fieldwork and literature. No critical biotopes and/or red-listed species exist within system
boundaries, merely general biotopes.
4.2.1.5 Östra Finland
Pamilo power station in river Vuoksi has been selected for the river region Östra Finland.
The river region Östra Finland is characterised by vast reservoirs and relatively low average
annual generation. The Pamilo station exploit 34 % of the total land and water area
that is exploited by the 14 selected stations and it contributes app. 3 % to the annual
average generation.
© Vattenfall AB Generation Nordic 2008
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