Beneden-Leeuwen - Side channel

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Beneden-Leeuwen - Side channel


Factsheet: Beneden-Leeuwen - Side channel

General
Country NL
River Name Waal
Site Name Beneden-Leeuwen - Side channel
River Characterisation
    River typology
    Location (Lat Lon) 51.8885706852741, 5.52809715270996
    Altitude lowland: < 200 m
    Catchment area very large: > 10000 km2
    Geology Siliceous
    National code/
    River type name
    R7
    Hydromorphological quality elements

    Biological quality elements
    Ecosystem Services
    EU Directives
    Pressures
    Measures
    Other
    Project size 18 ha
    Approximate costs
    Synergy Ecology & Flood protection
    Status Realised
    Period of realization 1994 - 1997
    Evaluation Hydromorphological and ecological changes
    Implemented by Rijkswaterstaat


    Key features of the case study

    Site description

    Beneden-Leeuwen is a site situated along the river Waal, a tributary of the Rhine in the Netherlands. It is characterized by a number of old sand and clay excavation pits and a cut of meander which was part of the Waal river prior to canalization. The floodplain was largely cut off from the main channel due to dikes situated on the banks of the river. The banks are fortified and groynes are in place in the channel. This has led to a decrease in hydromorphological processes and a subsequent decrease in ecological value of the area.

    Measures selection

    In an attempt to restore the ecological potential of the area as well as fortifying the dikes a deep sand and a clay excavation pit were connected. During high water this clay pit was connected to a former river bend. In years to follow a number of clay pits were dug and three secondary branches were connected, leading to a side channel. This side channel was connected to the main river, creating a side channel which flows with the river during 95% of the time. During low water levels the flow in the channel is reduced by a sill between the sand pit and the channel. The clay that was dug up from the clay pits was used to fortify dikes in the area. These dikes were not yet up to the set national standard. This measure made it possible to both fortify the dikes and at the same time facilitate ecological development of the area.

    Success criteria

    The project served as a pilot to monitor and analyse the effects. Scientific research was done on the channel to identify if the channel indeed served to (re)create habitat and biotopes that had disappeared due to channelization and artificial alterations of the Rhine and its tributaries in the Netherlands. The primary success criteria in this research were an increase in characteristic wading birds, fish and macro invertebrates.

    Ecological response

    Hydromorphological response

    Monitoring before and after implementation of the project

    Socio-economic aspects

    Contact person within the organization

    Extra background information

    References


    Related Measures

    Related Pressures