Case study:Restoration of the river Børselva

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Location: 68° 18' 13.95" N, 16° 42' 48.11" E
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Project overview

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Status In progress
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
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Project summary

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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

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www.fylkesmannen.no/contentassets/74f02cdd90cb485ea8def16785a345d3/ballangen---borselva---2016---etterundersokelser-etter-restaureringstiltak---vannvegetasjon-og-fisk---niva-rapp-7083-2016.pdf

Lessons learnt

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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.


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Catchment and subcatchment



Site

Name Børselva
WFD water body codes 172-5-R (EU-ID:NO172-5-R)
WFD (national) typology RNM2321
WFD water body name Børselva
Pre-project morphology
Reference morphology
Desired post project morphology
Heavily modified water body No
National/international site designation Norway - Naturreservat
Local/regional site designations National Reserve
Protected species present Yes
Invasive species present No
Species of interest
Dominant hydrology
Dominant substrate
River corridor land use Broadleaf/mixed woodland (semi natural), g
Average bankfull channel width category
Average bankfull channel width (m)
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Average bankfull channel depth (m)
Mean discharge category
Mean annual discharge (m3/s) 0.150.15 m³/s <br />150 l/s <br />
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Average unit stream power (W/m2)


Project background

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Reasons for river restoration

Mitigation of a pressure
Hydromorphology
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Measures

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Floodplain / River corridor
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Monitoring

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Supplementary Information

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