Case study:Restoration of the river Børselva: Difference between revisions
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|Protected species present=Yes | |Protected species present=Yes | ||
|Invasive species present=No | |Invasive species present=No | ||
|River corridor land use=Broadleaf/mixed woodland (semi natural), | |Dominant hydrology=Artificially regulated, | ||
|River corridor land use=Broadleaf/mixed woodland (semi natural), Improved/semi-improved grassland/pasture, Wetland, Tall herb/rank vegetation, | |||
|Mn discharge=0.15 | |Mn discharge=0.15 | ||
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Revision as of 10:19, 6 December 2019
This case study is pending approval by a RiverWiki administrator.
Project overview
Status | In progress |
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Project web site | |
Themes | Habitat and biodiversity, Hydropower, Hydromorphology, Land use management - agriculture |
Country | Norway |
Main contact forename | Lars |
Main contact surname | Sæter |
Main contact user ID | |
Contact organisation | County Governor of Nordland |
Contact organisation web site | http://www.fylkesmannen.no/nordland |
Partner organisations | The Norwegian Water Resources and Energy Directorate (NVE), Ballangen Energi AS, Norwegian Institute for Water Research (NIVA) |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
Condition in 1999 - before measures: Siltation and overgrowth of macrophytes due to greatly reduced water flow (hydropower regulation) and drainage from agriculture. Very poor conditions for fish and other aquatic organisms. Nearly 70% of the water area in Børselva was covered by plants. Important wetland biotopes for wetland birds were about to disappear. Large parts of the trout’s spawning and growing areas were destroyed.
Measures implemented: Measures in the agricultural channel ("Bruksåskanalen"): Erosion control, establishment of sedimentation ponds with vegetation filters and revegetation along the channel. Establishment of three paved thresholds in Børselva, laying of spawning gravel. 1 km of the overgrown part of the river was opened with an excavator and by laying of fiber fabric with stone and gravel on top. Dredging and opening of the rest of the Børselva with a large excavator ("Langemann"). Testing of different water discharges in Børselva (from the dam in Børsvatnet) - main focus on “flushing floods” and winter water flow.
Condition in 2019 – after measures: Studies show major environmental improvements, but the environmental objectives of good chemical status and good ecological potential have not yet been achieved. Further measures are required to reduce agricultural runoff and to implement the final regime for environmentally based water discharges. As of 2019, the hydroelectric license is under review at NVE (The Norwegian Water Resources and Energy Directorate).
Monitoring surveys and results
www.fylkesmannen.no/contentassets/74f02cdd90cb485ea8def16785a345d3/ballangen---borselva---2016---etterundersokelser-etter-restaureringstiltak---vannvegetasjon-og-fisk---niva-rapp-7083-2016.pdf
Lessons learnt
The measures in the Børselva watercourse (Børselvvassdraget) have created better water quality and hydrological continuity (open water flow) in the formerly overgrown watercourse. The flow levels have improved, self-cleaning has improved and pollution has been reduced. This has resulted in a more varied benthic fauna, better spawning and growing conditions for the trout and improved conditions for the bird fauna.
Image gallery
Catchment and subcatchment
Site
Project background
Cost for project phases
Reasons for river restoration
Measures
MonitoringHydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Any other monitoring, e.g. social, economic
Monitoring documents
Additional documents and videos
Additional links and references
Supplementary InformationEdit Supplementary Information
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