Opijnen - Side Channel

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Opijnen - Side Channel


Factsheet: Opijnen - Side Channel

General
Country NL
River Name Waal
Site Name Opijnen - Side Channel
River Characterisation
    River typology
    Location (Lat Lon) 51.8262299763673, 5.31103134155273
    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 10 ha
    Approximate costs
    Synergy Navigation
    Status Realised
    Period of realization 1994
    Evaluation Ecological change
    Implemented by Rijkswaterstaat


    Key features of the case study

    Site description

    The river Waal is a major tributary of the Rhine. Near the village of Opijnen a number of groyne fields were closed off in 1984 by the construction of a longitudinal dike. It was assumed at the time that this construction would improve navigation conditions for ship traffic on the Waal. The site is situated in the outer bend of a meander. By closing off these groyne fields the hydromorphological conditions were altered. Water flow was stopped, leading to static water bodies in the groynes. Also, sedimentation was influenced by the creation of the dike.

    Measures selection

    National natural and ecology policy led to measures being taken to restore part of the natural flow and dynamics in the channel that the dike had severed. This was undertaken in 1994. To do this without influencing the main channel, openings were made at two points in the dike (entrance & outlet) and between the groynes. This allowed water from the main channel to flow through. In essence a side channel was created. The side channel has a flow during 99% of the year due to the bed level and the bottom sill at the entrance of the channel. The measure was taken in hopes of artificially creating biotopes that no longer exist along the heavilly modified river Rhine.

    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