Post on 03-Nov-2020
transcript
Västerkvarn HPP, river
Kolbäcksån First migrating fish in a 100 years…
Site conditions
2016-08-30 2 Mälarenergi
• Kolbäcksån tributary to Galten, lake Mälaren with MQ 29 m3/s
• Västerkvarn most downstream migration obstacle, about 5 km from lake Mälaren
• Migratory fish species mainly Aspius aspius, Salmo trutta and Anguilla anguilla
• HPP built 1915 with QMAX: 45 m3/s
• HHPP: 6,7 m; HDAM: 2,8 m
• Problems regarding debree, ice buildup, head loss
• Complex site. canal, historical mill, bridges etc.
• Challenging site conditions and time schedule!
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Time plan
2016-08-30 4 Mälarenergi
• March: establishment, coffer
dams etc. Decision to adapt
HPP for migratory fish
• April: demolition works
• May-jul: foundation works etc.
• Aug-nov: concrete works
• Dec: first comissioning new
station
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Solutions
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Solutions
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Results
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After construction
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After construction
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After construction
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After construction
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Evaluation (early results)
• Counter deployed april 2016
• Within 1 week Aspius aspius passed
• Local record spawning of A. aspius
• Counter technichal issues – not reliable results
• Spawning A. aspius observed in uppermost pool
• S. trutta, A. anguilla, A. brama, R. rutilus, P. fluviatile
• Up- and downstream migration about same numbers of fish
• Mainly trout observed in bypass, also bream, perch and roach
Conclusions
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• Evaluation started before
construction had finished…
• Improved cost efficiency
coordinating projects (in this
case about 30% for fishway)
• Construction type of vertical
slot, not always cost effective
• Low incline, small spaced trash
racks works fine, but demands
adapted cleansing, especially
hydrodynamically shaped ones
Work just started…
2016-08-30 17 Mälarenergi
• Upstream HPP´s will be
evaluated for possible fish
migration solutions, dam
removal etc.
• HPP´s in river Hedströmmen,
Rällsälven and Svartån:
ongoing work for fish migration
and reproduction measures
Thank you for the attention!
2016-08-30 18 Mälarenergi