Case study:Remeandering of the Mardereau stream at Sorigny
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Project overview
Status | Complete |
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Project web site | |
Themes | Flood risk management, Habitat and biodiversity, Hydromorphology, Social benefits, Water quality |
Country | France |
Main contact forename | David |
Main contact surname | Laurendeau |
Main contact user ID | |
Contact organisation | Syndicat intercommunal d’aménagement de la vallée de l’Indre (SAVI) |
Contact organisation web site | |
Partner organisations | |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
The Mardereau stream is a small tributary of the Indre river. The catchment is dominated by crops and the intensification of agricultural pressures since 1941 has resulted in the creation of an extensive drainage network of and the disappearance of wetland habitats. Soil sealing in the watershed is increasing due to the proximity of the town of Tours. As a result the flood risk management issue is very relevant. At Sorigny the Mardereau was straightened, dredged and, in the upstream part, cemented.
Under the leadership of the Syndicat Intercommunal d’Aménagement de la Vallée de l’Indre (SAVI), a pilot restoration project has been realized. Works carried out included remeandering and plantation of riparian vegetation, together with some local biongeneering measures.
Monitoring surveys and results
Lessons learnt
Catchment and subcatchment
Edit the catchment and subcatchment details
(affects all case studies in this subcatchment)
Catchment
River basin district | Loire-Bretagne |
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River basin | Loire |
Subcatchment
River name | Mardereau |
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Area category | |
Area (km2) | 8.58.5 km² <br />850 ha <br /> |
Maximum altitude category | |
Maximum altitude (m) | |
Dominant geology | |
Ecoregion | Western Plains |
Dominant land cover | Intensive agriculture (arable) |
Waterbody ID |
Site
Name | Sorigny |
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WFD water body codes | FRGR2158 |
WFD (national) typology | |
WFD water body name | |
Pre-project morphology | Single channel |
Reference morphology | Actively meandering |
Desired post project morphology | |
Heavily modified water body | Yes |
National/international site designation | |
Local/regional site designations | |
Protected species present | No |
Invasive species present | No |
Species of interest | |
Dominant hydrology | |
Dominant substrate | |
River corridor land use | 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
Reach length directly affected (m) | 230230 m <br />0.23 km <br />23,000 cm <br /> |
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Project started | |
Works started | 2009/03/01 |
Works completed | 2009/03/31 |
Project completed | |
Total cost category | |
Total cost (k€) | 1919 k€ <br />19,000 € <br /> |
Benefit to cost ratio | |
Funding sources | 100 % Syndicat intercommunal d’aménagement de la vallée de l’Indre |
Cost for project phases
Phase | cost category | cost exact (k€) | Lead organisation | Contact forename | Contact surname |
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Investigation and design | |||||
Stakeholder engagement and communication | |||||
Works and works supervision | 1919 k€ <br />19,000 € <br /> | 100 % Syndicat intercommunal d’aménagement de la vallée de l’Indre | |||
Post-project management and maintenance | |||||
Monitoring |
Reasons for river restoration
Mitigation of a pressure | canalization of the stream |
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Hydromorphology | Channel pattern/planform |
Biology | |
Physico-chemical | |
Other reasons for the project |
Measures
Structural measures
| |
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Bank/bed modifications | riverbank revegetation, Introducing stones |
Floodplain / River corridor | |
Planform / Channel pattern | Re-meandering |
Other | |
Non-structural measures
| |
Management interventions | |
Social measures (incl. engagement) | |
Other | local students participated in works |
Monitoring
Hydromorphological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
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Before measures | After measures | Qualitative | Quantitative |
Biological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
---|---|---|---|---|---|---|
Before measures | After measures | Qualitative | Quantitative | |||
Invertebrates | Yes | Yes | No | No | No | |
Phytoplankton | No | Yes | No | No | No |
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
Element | When monitored | Type of monitoring | Control site used | Result | ||
---|---|---|---|---|---|---|
Before measures | After measures | Qualitative | Quantitative | |||
Public opinion | No | Yes | No | No | No |
Monitoring documents
Image gallery
Additional documents and videos
Additional links and references
Link | Description |
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Supplementary Information
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