Difference between revisions of "Case study:Habitat improvement measures in Bortneelva"

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|Project web site url=www.vannportalen.no/vannregioner/sogn--og-fjordane/vassomrade/nordfjord/nyhende-nordfjord/2017/miljotiltak-i-bortneelva/
|Project web site url=www.vannportalen.no/vannregioner/sogn--og-fjordane/vassomrade/nordfjord/nyhende-nordfjord/2017/miljotiltak-i-bortneelva/
|Themes=Habitat and biodiversity, Hydropower, Hydromorphology
|Themes=Environmental flows and water resources, Habitat and biodiversity, Hydropower, Hydromorphology
|Main contact forename=Vegard
|Main contact forename=Vegard

Revision as of 11:07, 4 December 2019

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Location: 61° 50' 49", 5° 23' 38"
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Project overview

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Status Complete
Project web site http://www.vannportalen.no/vannregioner/sogn--og-fjordane/vassomrade/nordfjord/nyhende-nordfjord/2017/miljotiltak-i-bortneelva/
Themes Environmental flows and water resources, Habitat and biodiversity, Hydropower, Hydromorphology
Country Norway
Main contact forename Vegard
Main contact surname Fagerli
Main contact user ID
Contact organisation SFE Produksjon AS
Contact organisation web site http://sfe.no/konsern
Partner organisations Svelgen Kraft AS, The Norwegian Public Roads Administration, County Governor of Vestland, Sub-district Nordfjord /Bremanger municipality, Uni Research Miljø LFI, Rådgivende Biologer AS
Parent multi-site project
This is a parent project
encompassing the following
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Project summary

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Svelgen Kraft (SK) utilize about 7% of the water that flows naturally in the Bortne-river for power production at the Svelgen I power plant. The established measures in the river will mitigate the impacts from this production and hopes to enhance the growing and living conditions for anadromous fish in the river.

At the request of landowners and a dialogue with the County Governor's environmental protection department, SK took the initiative to map the river. In the light of ongoing processes such as the EU's water framework directive and renewal of the concessions for the Svelgen I and II power plants, as well as SK's goal of operating environmentally sound water management, mapping and measures were prioritized. The survey was carried out by Uni Research Miljø LFI in 2016. Habitat conditions in the river was depicted and possible measures were suggested to improve the fish's growing and living conditions.

After clarification with landowners, other operators in the river and authorities, the physical work was carried out in autumn/winter 2016-17 by Machine3prenør1. Different types of measures have been established in an approximated 2 km long stretch of the river.

The following measures were done:

• Removal of migration barriers by building a “fish passage” with two ponds.

• Construction of flow deflectors to concentrate the stream of water in the river, which gives the fish easier migration paths in the case of low water levels.

• Laying of stone blocks and boulders in clusters to improve the fish's ability to hide.

• Digging of ditches and opening of a natural "fish tunnels" to drain water to migration paths at low water levels.

Monitoring surveys and results

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Lessons learnt

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Results so far:

Fish studies were conducted in 2018 by Rådgivende Biologer AS. Due to general low densities of juvenile fish in 2018, there were not enough data to say anything conclusive about the effects of the measures conducted in the river (Irgens, C. & Hellen, B.A. 2019. Fiskebiologiske undersøkelser i Bortneelva i 2018. Rådgivende Biologer AS, rapport 2910, 16 sider, ISBN 978-82-8308-63 3-1).

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Catchment and subcatchment


Name Bortneelva
WFD water body codes 086-141-R and 086-139-R
WFD (national) typology RWH1211
WFD water body name Bortneelva og Bortneelva, nedre del
Pre-project morphology
Reference morphology
Desired post project morphology
Heavily modified water body No
National/international site designation
Local/regional site designations
Protected species present Yes
Invasive species present No
Species of interest Salmon and Sea-trout
Dominant hydrology Artificially regulated
Dominant substrate Cobble
River corridor land use Grassland, Woodland
Average bankfull channel width category
Average bankfull channel width (m)
Average bankfull channel depth category
Average bankfull channel depth (m)
Mean discharge category
Mean annual discharge (m3/s) 2.1
2.1 m³/s
2,100 l/s
Average channel gradient category
Average channel gradient
Average unit stream power (W/m2)

Project background

Reach length directly affected (m) 2000
2,000 m
2 km
200,000 cm
Project started 2014/01/01
Works started
Works completed
Project completed 2017/01/01
Total cost category
Total cost (k€)
Benefit to cost ratio
Funding sources Svelgen Kraft AS, The Norwegian Public Roads Administration and Sub-district Nordfjord /Bremanger municipality

Cost for project phases

Phase cost category cost exact (k€) Lead organisation Contact forename Contact surname
Investigation and design
Stakeholder engagement and communication
Works and works supervision
Post-project management and maintenance

Reasons for river restoration

Mitigation of a pressure Hydropower, Barriers to fish migration
Biology Fish
Other reasons for the project


Structural measures
Bank/bed modifications Deflectors, Creation of fish passes, Removal of fish barriers, Creation of pools, Creation of fish refuge areas, introduction of blocks, Big rocks are placed in the stream, Creation of low flow channel
Floodplain / River corridor Improving fish migration
Planform / Channel pattern
Non-structural measures
Management interventions
Social measures (incl. engagement)


Hydromorphological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Biological quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative
Fish Yes Yes No No No Inconclusive

Physico-chemical quality elements

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Any other monitoring, e.g. social, economic

Element When monitored Type of monitoring Control site used Result
Before measures After measures Qualitative Quantitative

Monitoring documents

Additional documents and videos

Additional links and references

Link Description
http://docplayer.me/50826638-Habitatkartlegging-i-bortneelva-bremanger-kommune.html Measures plan
http://www.radgivende-biologer.no/wp-content/uploads/2019/10/2910.pdf Report

Supplementary Information

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