Case study:Remeandering of the Mardereau stream at Sorigny
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Project overview
| Status | Complete |
|---|---|
| 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
At Sorigny, the Mardereau stream has been rectified, re.... and partially .... It has water quality problems too, especially due to an old treatment plant.
Under the leadership of the syndicat intercommunal d’aménagement de la vallée de l’Indre (SAVI), a pilot restoration project has been realized.
The restoration works consist in recreating new meanders, put in place of blocks and stones and reconnecting portions of the old riverbed, supported by bioengineering actions including revegetation.
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 |
|---|---|
| River basin | Loire |
Subcatchment
| River name | Mardereau |
|---|---|
| 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 |
|---|---|
| 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 /> |
|---|---|
| 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 |
|---|---|---|---|---|---|
| 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 |
|---|---|
| Hydromorphology | Channel pattern/planform |
| Biology | |
| Physico-chemical | |
| Other reasons for the project |
Measures
Structural measures
| |
|---|---|
| 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 partecipated in works |
Monitoring
Hydromorphological quality elements
| Element | When monitored | Type of monitoring | Control site used | Result | ||
|---|---|---|---|---|---|---|
| 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 |
|---|
Supplementary Information
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