Case study:Agreed definition of mobility area for the Adour
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Project overview
Status | In progress |
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Project web site | |
Themes | |
Country | France |
Main contact forename | Fréderic |
Main contact surname | Ré |
Main contact user ID | |
Contact organisation | Institution Adour |
Contact organisation web site | |
Partner organisations | |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
The Adour is an highly mobile, braided piedmont watercourse and constitutes one of the primary resources for alluvial materials in the Adour-Garonne basin. From the 1960s, large amounts of aggregates were extracted from both its main channel and associated floodplain. These activities caused a significant incision of the main channel, reducing the frequency of flooding into the floodplain, lowering the ground water table and cutting off ancient meanders, etc. Thus erosion of the banks occurred, which prompted the managing authorities to stabilise its cross-sectional and longitudinal profile: major embankments, weirs and protective structures for banks (covering 26% of banks) were subsequently constructed on the Adour.
In order to put a stop to isolated responses to demands for riverbank consolidation without the implementation of a global approach, the Institution Adour and the two local associations conducted a joint study of how to design an integrated, acceptable and sustainable management programme for the Adour’s mobility area. The consultation with stakeholders in the area led to the definition of a permissible mobility area covering 1,744 hectares.
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 | Hautes-Pyrénées et Ger |
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River basin | Adour - Garonne |
Subcatchment
River name | L'Adour |
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Area category | more than 10000 km² |
Area (km2) | 17000 km²1,700,000 ha <br /> |
Maximum altitude category | |
Maximum altitude (m) | |
Dominant geology | |
Ecoregion | Western Plains |
Dominant land cover | Intensive agriculture |
Waterbody ID |
Site
Name | Hautes-Pyrénées et Ger |
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WFD water body codes | FRFR327C |
WFD (national) typology | |
WFD water body name | |
Pre-project morphology | Braided, Entrenched, Embanked |
Reference morphology | Braided |
Desired post project morphology | |
Heavily modified water body | true |
National/international site designation | |
Local/regional site designations | |
Protected species present | |
Invasive species present | |
Species of interest | |
Dominant hydrology | |
Dominant substrate | Gravel |
River corridor land use | Intensive agriculture, Urban |
Average bankfull channel width category | 10 - 50 m |
Average bankfull channel width (m) | 2020 m <br />0.02 km <br />2,000 cm <br /> |
Average bankfull channel depth category | |
Average bankfull channel depth (m) | |
Mean discharge category | |
Mean annual discharge (m3/s) | 3535 m³/s <br />35,000 l/s <br /> |
Average channel gradient category | |
Average channel gradient | 0.002 |
Average unit stream power (W/m2) | 34.324534.325 W/m² <br /> |
Project background
Reach length directly affected (m) | 44000 m44 km <br />4,400,000 cm <br /> |
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Project started | 2005/01/01 |
Works started | 2008/01/01 |
Works completed | 2018/01/01 |
Project completed | |
Total cost category | 1000 - 5000 k€ |
Total cost (k€) | 3733 k€3,733,000 € <br /> |
Benefit to cost ratio | |
Funding sources | Water Agency, Institution Adour, Regional Council, French State |
Cost for project phases
Phase | cost category | cost exact (k€) | Lead organisation | Contact forename | Contact surname |
---|---|---|---|---|---|
Investigation and design | 100 - 500 k€ | 130 k€130,000 € <br /> | |||
Stakeholder engagement and communication | 50 - 100 k€ | 55 k€55,000 € <br /> | |||
Works and works supervision | 1000 - 5000 k€ | 2580 k€2,580,000 € <br /> | Water Agency | ||
Post-project management and maintenance | |||||
Monitoring | 100 - 500 k€ | 130 k€130,000 € <br /> |
Reasons for river restoration
Measures
Structural measures
| |
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Bank/bed modifications | Removal/retreat of bank protection |
Floodplain / River corridor | Restoration of riparian forest |
Planform / Channel pattern | |
Other | |
Non-structural measures
| |
Management interventions | Definition of erodble corridor |
Social measures (incl. engagement) | |
Other | Consultation |
Monitoring
Hydromorphological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
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Before measures | After measures | Qualitative | Quantitative | |||
Channel pattern/planform | Yes |
Biological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
---|---|---|---|---|---|---|
Before measures | After measures | Qualitative | Quantitative |
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 |
Monitoring documents
Image gallery
Additional documents and videos
Additional links and references
Link | Description |
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