Case study:Gammelelva

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Location: 63° 13' 3.56" N, 10° 18' 24.70" E

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Project overview

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Status	Complete
Project web site
Themes	Habitat and biodiversity
Country	Norway
Main contact forename	Per Ivar
Main contact surname	Bergan
Main contact user ID
Contact organisation	Governor of Trøndelag
Contact organisation web site	http://www.fylkesmannen.no/Trondelag
Partner organisations	Sweco
Parent multi-site project
This is a parent project encompassing the following projects	No

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Project summary

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This restoration project is part of a management plan for an ox-bow lake protected as a nature reserve in 1993. The lake is under pressure from new infrastructure and runoff from nearby agricultural land. The main pressure was eutrophication. An overall aim for the project is to restore ain reopen the lake and open water to protect and secure the future survival of rare forest type and animal life. This imply to extend the survival of thi nature type, that naturally is a dynamic habitat and will eventuelly dry out. Due to pressure on natural river systems the establishment of new ox-bow lakes is very limited. Ox-bow lake is a redlisted nature type (Norwegian Redlist). In 2012/2013 large quantities of sediments were excavated, and removed from Gammelelva. This resulted in more open water.

Monitoring surveys and results

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The status of the lake was monitored before the restoration: Area of open water (from airal photo 1947 - 2011). Status for species (plants, insects, zooplankton, amphibians, fish and birds) has been mapped. There are no spesific plans for further monitoring after restoration.

Lessons learnt

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This project gave interesting experience from the practical side, in cooperation with the entrepreneur. The project was highly wanted from management authorities and involved partners. The local people are a bit more biased, due to rewetting and changes in the areas, and fair for less recreation values. The output is partly successful, but the pressure from surrondings in combination with the natural prosesses is challenging, and the status of the oxbow-lake will still be changing. A need for continuous management to mainstain the habitat.

Image gallery

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Catchment and subcatchment Select a catchment/subcatchment Site Edit site Name Gammelelva nature reserve WFD water body codes WFD (national) typology WFD water body name 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 Yes Species of interest invasive lupin in near surrondings Dominant hydrology oxbow-lake Dominant substrate wetland River corridor land use infrastructure, Intensive agriculture (arable) 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) Average channel gradient category Average channel gradient Average unit stream power (W/m2) Project background Edit project background Reach length directly affected (m) Project started 2011 Works started Works completed Project completed Total cost category Total cost (k€) 3000030,000 k€ <br />30,000,000 € <br /> Benefit to cost ratio Funding sources Environmental management authorities Cost for project phases Phase cost category cost exact (k€) Lead organisation Contact forename Contact surname Investigation and design Sweco Per Ivar Bergan Stakeholder engagement and communication Local farmers and landowners Works and works supervision Sweco Per Ivar Bergan Post-project management and maintenance Governor of Trondelag Jan-Erik Andersen Monitoring Reasons for river restoration Edit reasons for restoration Mitigation of a pressure Infrastructure delevopment, agriculture Hydromorphology road and railway crossing the river Biology euthropication, invasive species Physico-chemical eutrophication Other reasons for the project Measures Edit Measures Structural measures Bank/bed modifications Floodplain / River corridor Area of open water Planform / Channel pattern Other Non-structural measures Management interventions Social measures (incl. engagement) Other Monitoring Hydromorphological quality elements Edit Hydromorphological quality elements Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Channel pattern/planform Yes Yes No Yes No Improvement Biological quality elements Edit biological quality elements Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Physico-chemical quality elements Edit 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 Edit Other responses Element When monitored Type of monitoring Control site used Result Before measures After measures Qualitative Quantitative Monitoring documents Upload monitoring documents Additional documents and videos Upload additional documents Additional links and references Edit links and references Link Description Supplementary Information Edit Supplementary Information