General
National Id
Luxembourg_01
Site name
Alzette in Schifflange
Summary
In the 50's and 60’s, the alluvial plain of the Alzette river was deeply modified in order to develop intensive agriculture. As a result, the water retention was reduced and ecological value declined. The project aimed at restoring the ecological state of the Alzette in Drumontshaff (Luxembourg). The two mains tasks of the project were to restore the natural functioning of the Alzette river (frequent overflowing and flooding of aside land, wetland habitats restoration) and to develop an extensive management of aside meadows (late mowing, no fertilizer or biocidal product, etc.).
The first step was to determine the floodplain through past and current reference values. After the feasibility study, a reallocation scheme was drown. An agronomic feasibility study was made to determine socio-economic solutions. The river and hydraulic annexes were restored (lateral enlargement or displacement of the river bed into natural thalweg). Finally, the restoration of the complete flood plain was possible.
The first step was to determine the floodplain through past and current reference values. After the feasibility study, a reallocation scheme was drown. An agronomic feasibility study was made to determine socio-economic solutions. The river and hydraulic annexes were restored (lateral enlargement or displacement of the river bed into natural thalweg). Finally, the restoration of the complete flood plain was possible.
The in-depth description of the case study
NUTS Code
Luxembourg
RBD code
LU RB_000
Transboundary
0
Data provider
Alexandra Rossi, ACTeon
Source(s)
NWRM(s) implemented in the case study
Longitude
6.0142918
Latitude
49.5057481
Site information
Climate zone
cool temperate moist
Mean rainfall
853
Mean rainfall unit
mm/year
Average temperature
9
Type
Case Study Info
Light or indepth?
In-depth
Design & implementations
Application scale
Field Scale
Performance timescale
< 1 year
Area (ha)
40
Area subject to Land use change or Management/Practice change (ha)
10
Design capacity description
The project was designed to restore the natural functions of the river and of its flood plain. Works were designed on this principle. Another important target was the management of the area after the project. This involved extensive agriculture and extensive grazing. The overall land planning enriched the landscape and its aesthetic value.
Design contractual arrangement
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Design consultation activity
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Design land use change
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Design authority
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Lessons, risks, implications...
Key lessons
The Alzette restoration led to the development of extensive agriculture. The high quality productions are valued and sold locally. The river restoration has a positive impact on flood risk, water quality and biodiversity.
Success factor(s)
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Financing
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Driver
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Financing share
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Policy, general governance and design targets
Policy description
In the 50s and the 60s, the alluvial plain of the Alzette river was deeply modified. The river was channelized, the valley bottom was drained and dried, intensive agriculture had been developed. As a consequence, this land planning increased flood risk downstream and had a significant impact on biodiversity and landscape.
Policy target
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Runoff control
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Peak-flow reduction
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Erosion Control
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Improved Biodiversity
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Policy pressure
| Pressure directive | Relevant pressure |
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Policy area
| Policy area type | Policy area focus | Name | Comments |
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Policy impact
| Impact directive | Relevant impact |
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Policy wider plan
| Wider plan type | Wider plan focus | Name | Comments |
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Policy requirement directive
| Requirement directive | Specification |
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Socio-economic
Direct benefits information
The main benefit is due to biodiversity improvement.
Costs investment information
No information available
Costs operation maintenance
No information available
Costs total information
No information available
Ecosystem improved biodiversity
1
Information on Ecosystem improved biodiversity
The extensive grazing and the restoration of the river and of wetlands were beneficial for water quality and for the development of biodiversity (insects, birds, bats, etc.).
Ecosystem provisioning services
1
Information on Ecosystem provisioning services
The development of a didactic path is beneficial for local citizens and tourists who can walk in the area an learn about its management.
Ecosystem impact climate regulation
Increased permanent biomas
Biophysical impacts
Information on runoff reduction
Wetland functions of the area were restored. The flood plain is filled by rain falls and then restitutes water. As a consequence, the project led to a reduction in runoff. However, this effect has not been quantified.
Information on Peak flow rate reduction
The rainwater storage in the wetland shifts the peak flow and reduces it thanks to the overall vegetation and natural pounds. However, this effect has not been quantified.
Information on Water quality overall improvements
Wetlands have self purifying capacities. In contrast to channeled rivers, wetlands and pounds increase oxygen exchange. This oxygen allows the development of activities of micro-organisms which degrade organic matter. Wetlands are also a place of sedimentation.
Information on Soil quality overall soil improvements
N/A
