Case study:River Dulais Restoration Project: Difference between revisions
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|Partner organisations=Environment Agency Wales, | |Partner organisations=Environment Agency Wales, | ||
|Multi-site=No | |Multi-site=No | ||
|Project picture=Fig 5 - River Dulais one year after completion .JPG | |||
|Picture description=River Dulais one year after restoration works completed | |||
|Project summary=The River Dulais is typical of many local rivers, where unrestricted grazing, mostly by sheep, has resulted in a loss of bankside vegetation. Accordingly, there is reduced cover for fish, bank/bed instability and increased erosion. Traditionally, the approach was to extensively fence off rivers and introduce revetments, but this project looked to introduce the option of softer engineering and river restoration to the catchment. | |Project summary=The River Dulais is typical of many local rivers, where unrestricted grazing, mostly by sheep, has resulted in a loss of bankside vegetation. Accordingly, there is reduced cover for fish, bank/bed instability and increased erosion. Traditionally, the approach was to extensively fence off rivers and introduce revetments, but this project looked to introduce the option of softer engineering and river restoration to the catchment. | ||
Revision as of 08:33, 3 September 2012
This case study is pending approval by a RiverWiki administrator.
Project overview
Status | Complete |
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Project web site | |
Themes | Fisheries, Habitat and biodiversity |
Country | Wales |
Main contact forename | Nick |
Main contact surname | Elbourne |
Main contact user ID | |
Contact organisation | River Restoration Centre |
Contact organisation web site | http://www.therrc.co.uk |
Partner organisations | Environment Agency Wales |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
The River Dulais is typical of many local rivers, where unrestricted grazing, mostly by sheep, has resulted in a loss of bankside vegetation. Accordingly, there is reduced cover for fish, bank/bed instability and increased erosion. Traditionally, the approach was to extensively fence off rivers and introduce revetments, but this project looked to introduce the option of softer engineering and river restoration to the catchment.
A variety of techniques were used to restore the river, including bank grading and toe protection using live willow bundles. In deep stretches of the river with more powerful flow, upturned trees were installed to act as natural revetments. Trees were also planted to steady the banks, with all trees additionally providing further habitat.
Monitoring surveys and results
Lessons learnt
Catchment and subcatchment
Edit the catchment and subcatchment details
(affects all case studies in this subcatchment)
Site
Name | River Dulais |
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WFD water body codes | GB110060036210 |
WFD (national) typology | |
WFD water body name | Dulais - conf with Ddu to confluence with Tywi |
Pre-project morphology | |
Reference morphology | |
Desired post project morphology | |
Heavily modified water body | No |
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 | |
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 | 0.01 - 0.1 |
Average channel gradient | |
Average unit stream power (W/m2) |
Project background
Reach length directly affected (m) | 500 m0.5 km <br />50,000 cm <br /> |
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Project started | 2004/05/01 |
Works started | |
Works completed | |
Project completed | 2004/05/31 |
Total cost category | 10 - 50 k€ |
Total cost (k€) | 33 k€33,000 € <br /> |
Benefit to cost ratio | |
Funding sources |
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 | 3333 k€ <br />33,000 € <br /> | Salix | |||
Post-project management and maintenance | |||||
Monitoring |
Supplementary funding information
Works split into €20k for revetment work and €13k for fencing
Reasons for river restoration
Measures
Structural measures
| |
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Bank/bed modifications | Bank stabilisation |
Floodplain / River corridor | Control of riparian vegetation, Creation of wetlands |
Planform / Channel pattern | Channel narrowing |
Other | |
Non-structural measures
| |
Management interventions | Fencing |
Social measures (incl. engagement) | |
Other |
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 |
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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http://www.therrc.co.uk/case studies/rrn%20issue%2023.pdf | River Restoration Centre news article |
Supplementary Information
Edit Supplementary Information