Case study:Rhymney Great Wharf

From RESTORE
Jump to: navigation, search
0.00
(0 votes)


To discuss or comment on this case study, please use the discussion page.


Location: 51° 29' 58", -3° 5' 25"
Edit location
Loading map...
Left click to look around in the map, and use the wheel of your mouse to zoom in and out.


Project overview

Edit project overview
Status Complete
Project web site http://www.therrc.co.uk/sites/default/files/projects/57_rhymney.pdf
Themes Flood risk management, Habitat and biodiversity
Country Wales
Main contact forename Huw
Main contact surname Alford
Main contact user ID
Contact organisation Natural Resources Wales
Contact organisation web site http://naturalresources.wales/?lang=en
Partner organisations Atkins
Parent multi-site project
This is a parent project
encompassing the following
projects
No
Project picture

Project summary

Edit project overview to modify the project summary.


The Severn Estuary foreshore has international importance, reflected by the following designations: Site of Special Scientific Interest (SSSI), Special Protection Area (SPA), possible Special Area of Conservation (pSAC) and Ramsar. The site itself is located seaward of the Wentlooge Sea Defences, where the upper, vegetated saltmarsh is referred to as the 'wharf' and the lower unvegetated foreshore as the 'mudflats'. The Wentlooge Sea Defences (Map 1) protect an area of low-lying land, of which approximately 32km2 lies below mean high water springs (MHWS). The wharf acts as part of the sea defence by reducing the incident wave energy on the embankments themselves. Study of the foreshore highlighted that the wharf had been eroding locally at a fairly constant rate over a long period. In 2003, pockets of erosion were in close proximity to the flood defence embankment and as such continued erosion was predicted to undermine the embankment by the year 2008. As an immediate mitigation against further erosion of the wharf, thus protecting the defences, it was decided to use harder, more traditional engineering in the form of blockstone and rip-rap. As a longer term strategy, polder were used in an effort to regenerate the mudflats and increase protection to the wharf scarp. The works that were carried out have effectively stopped/slowed the erosion of the wharf, thus: • maintaining the ecologically important land • preventing the undermining of the defences and maintaining their function • protecting ~30km2 of agricultural land, business and numerous communities within the Wentlooge Levels

Monitoring surveys and results

This case study hasn’t got any Monitoring survey and results, you can add some by editing the project overview.

Lessons learnt

This case study hasn’t got any lessons learnt, you can add some by editing the project overview.


Image gallery


ShowHideAdditionalImage.png


Catchment and subcatchment



Site

Name
WFD water body codes
WFD (national) typology
WFD water body name
Pre-project morphology
Reference morphology
Desired post project morphology
Heavily modified water body
National/international site designation
Local/regional site designations
Protected species present
Invasive species present
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
Average channel gradient
Average unit stream power (W/m2)


Project background

Reach length directly affected (m)
Project started
Works started
Works completed
Project completed
Total cost category
Total cost (k€) £1.6m
"£" is not declared as a valid unit of measurement for this property.
Benefit to cost ratio
Funding sources Welsh Government

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



Reasons for river restoration

Mitigation of a pressure Flood and coastal erosion protection
Hydromorphology
Biology
Physico-chemical
Other reasons for the project


Measures

Structural measures
Bank/bed modifications
Floodplain / River corridor
Planform / Channel pattern
Other Salt marsh and mudflat restoration
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

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



Additional documents and videos


Additional links and references

Link Description

Supplementary Information

Edit Supplementary Information