Case study:Nar SSSI project: Difference between revisions
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Revision as of 13:34, 9 August 2012
This case study is pending approval by a RiverWiki administrator.
Project overview
Status | Complete |
---|---|
Project web site | |
Themes | Hydromorphology, Monitoring, Spatial planning |
Country | England |
Main contact forename | Nick |
Main contact surname | Elbourne |
Main contact user ID | User:NickRRC |
Contact organisation | River Restoration Centre |
Contact organisation web site | http://www.therrc.co.uk |
Partner organisations | |
Parent multi-site project | |
This is a parent project encompassing the following projects |
No |
Project summary
The existing river was an artificially wide channel with virtually no gradient. The existing wooden flow deflectors installed between 2002 and 2003 were insufficient in their attempts to enhance flow diversity. The project successfully narrowed the river through the construction of artificial berms mimicking those found naturally and the excavation of pools.
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 | Anglian |
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River basin | North West Norfolk |
Subcatchment
River name | Nar |
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Area category | |
Area (km2) | |
Maximum altitude category | |
Maximum altitude (m) | |
Dominant geology | |
Ecoregion | |
Dominant land cover | |
Waterbody ID |
Site
Name | Narbough Trout Fishery |
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WFD water body codes | GB105033047791 |
WFD (national) typology | |
WFD water body name | Nar to confl with Blackborough Drain |
Pre-project morphology | Single channel, Straight, Embanked, High width:depth |
Reference morphology | Sinuous, Pool-riffle |
Desired post project morphology | |
Heavily modified water body | Yes |
National/international site designation | UK - Site of Special Scientific Interest |
Local/regional site designations | |
Protected species present | No |
Invasive species present | No |
Species of interest | Water Vole |
Dominant hydrology | Groundwater |
Dominant substrate | Silt, Sand |
River corridor land use | Urban, Woodland, Grassland |
Average bankfull channel width category | 10 - 50 m |
Average bankfull channel width (m) | |
Average bankfull channel depth category | 5 - 10 m |
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) | 1000 m1 km <br />100,000 cm <br /> |
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Project started | 2011/02/01 |
Works started | |
Works completed | 2011/03/01 |
Project completed | |
Total cost category | |
Total cost (k€) | 3 k€3,000 € <br /> |
Benefit to cost ratio | |
Funding sources |
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 | |||||
Post-project management and maintenance | |||||
Monitoring |
Supplementary funding information
The entire project, covering 1 km of channel, was delivered by a team of 3 people in less than 3 days and for under 3 thousand pounds. Accordingly, although early days, it seems that the Nar SSSI project can be viewed as a successful low-cost ‘quick win’ project in a constrained site.
Reasons for river restoration
Measures
Structural measures
| |
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Bank/bed modifications | Creation of shoulders, Material was removed from bed to build out banks, Creation of pools downstream |
Floodplain / River corridor | Ensure floodplains left unmodified |
Planform / Channel pattern | Narrowing of channel |
Other | Maintain water vole habitat |
Non-structural measures
| |
Management interventions | |
Social measures (incl. engagement) | |
Other |
Monitoring
Hydromorphological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
---|---|---|---|---|---|---|
Before measures | After measures | Qualitative | Quantitative | |||
Flow velocities | Yes | Yes | Yes | Awaiting results | ||
Quantity & dynamics of flow | Yes | Yes | Yes | Awaiting results |
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/rrc%20case%20study%20-%20narborough%202011.pdf | River Restoration Centre Case Study |