Difference between revisions of "Spree - Restoration and remeandering of the Müggelspree - downstream Mönchwinkel"

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==Site description==
 
==Site description==
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The Müggelspree is a sixth-order section of the Lower River Spree that extends from Große Tränke to the village of Neu Zittau, east of Berlin. As a result of the river straightening described above, the Müggelspree has a trapezoid channel profile with a mean slope of 0.015%, a mean water depth of 1.25m at medium discharge, and a mean channel width of 25 m (Schulz et al. 2003). Between 1998 and 2002, discharge has ranged between 2.5m3 s−1 in summer and 30m3 s−1 in early spring (Schulz et al. 2003). In the early 1990s, the Lower River Spree changed from a turbid to a macrophyte-dominated state (Köhler and Hoeg, 2000). Shifting sand covers the midstream riverbed, whereas stable sand prevails in the lateral parts of the riverbed. The latter is often colonized by macrophytes or mussels. Total nitrogen and total phosphorus concentrations range between 0.7 and 3.4mg N l−1, and 70 and 180g P l−1, respectively. (Schulz et al. 2003). Therefore, the Lower River Spree is classified as a eutrophic section. About 53% of its banks are lined by trees such as willow trees (''Salix'' spp.), poplar trees (''Populus'' spp.), and alder trees (''Alnus glutinosa'') (Schulz et al. 2003).
  
 
==Measures selection==
 
==Measures selection==

Revision as of 15:31, 29 January 2014

Spree - Restoration and remeandering of the Müggelspree - downstream Mönchwinkel


Factsheet: Spree - Restoration and remeandering of the Müggelspree - downstream Mönchwinkel

General
Country DE
River Name Spree
Site Name Spree - Restoration and remeandering of the Müggelspree - downstream Mönchwinkel
River Characterisation
    River typology
    Location (Lat Lon) 52.377747, 13.878897
    Altitude lowland: < 200 m
    Catchment area large: > 1000 - 10000 km2
    Geology Siliceous
    National code/
    River type name
    Mid-sized lowland river
    Hydromorphological quality elements

    Biological quality elements
    Ecosystem Services
    EU Directives
    Pressures
    Measures
    Other
    Project size 0.95 km
    Approximate costs
    Synergy
    Status Realised
    Period of realization 2005
    Evaluation Hydromorphological and ecological changes


    Key features of the case study

    In the following section, background and motives of the restoration project which led to the initiation of the project are introduced.

    Drivers and pressures

    Various hydro-engineering measures led to an extreme degradation of the River Spree until the 60s of the 20th century. In order to facilitate flood protection, generation of energy by water mills, agricultural use of the wetlands, and shipping, the river was channelized by (I) shore fortification by rip-rap or hybrid poplar plantings, (II) meander cutting, and (III) constructing a symmetrical trapezoidal cross-section. The mean discharge was artificially increased by the removal of ground water during upstream open-cast lignite mining activities. As a consequence, the river lost most of its natural variability of the flow regime, sediments, and morphology leading to subsequent degradation of the riverine biota.

    Global objective

    In 2004, the Federal State of Brandenburg started implementing an intense restoration program in one section of the River Spree, the so called Müggelspree. The main objective of this program was to reconnect the previously cut meanders to the main channel. Since then, several old oxbows have been dredged and reconnected on both sides of the main channel. The reconnection of oxbows was accompanied by the removal of rip-raps and groynes and the replacement of the introduced hybrid poplars by native willows, oaks, or alders.

    Specific goals

    The restoration and re-meandering of the Müggelspree aimed to:

    • Restore the natural hydrology, morphology, and oxygen balance of the river
    • Improve water retention in the landscape
    • Develop habitats to improve benthic and rheophil species

    Site description

    The Müggelspree is a sixth-order section of the Lower River Spree that extends from Große Tränke to the village of Neu Zittau, east of Berlin. As a result of the river straightening described above, the Müggelspree has a trapezoid channel profile with a mean slope of 0.015%, a mean water depth of 1.25m at medium discharge, and a mean channel width of 25 m (Schulz et al. 2003). Between 1998 and 2002, discharge has ranged between 2.5m3 s−1 in summer and 30m3 s−1 in early spring (Schulz et al. 2003). In the early 1990s, the Lower River Spree changed from a turbid to a macrophyte-dominated state (Köhler and Hoeg, 2000). Shifting sand covers the midstream riverbed, whereas stable sand prevails in the lateral parts of the riverbed. The latter is often colonized by macrophytes or mussels. Total nitrogen and total phosphorus concentrations range between 0.7 and 3.4mg N l−1, and 70 and 180g P l−1, respectively. (Schulz et al. 2003). Therefore, the Lower River Spree is classified as a eutrophic section. About 53% of its banks are lined by trees such as willow trees (Salix spp.), poplar trees (Populus spp.), and alder trees (Alnus glutinosa) (Schulz et al. 2003).

    Measures selection

    Success criteria

    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