Case study:Poyle channel enhancement and weir removal

From RESTORE
Jump to: navigation, search
This case study is pending approval by a RiverWiki administrator.
Approve case study

 

0.00
(0 votes)


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


Location: 51° 28' 39", -0° 30' 50"
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
Themes Fisheries, Flood risk management, Habitat and biodiversity
Country England
Main contact forename Usha
Main contact surname Chapman
Main contact user ID
Contact organisation Environment Agency
Contact organisation web site http://www.gov.uk/government/organisations/environment-agency
Partner organisations
Parent multi-site project
This is a parent project
encompassing the following
projects
No
This case study hasn’t got a picture, you can add one by editing the project overview.

Project summary

Edit project overview to modify the project summary.


Primary objectives - Manage flood risk; improve upstream habitat; manage water level; reduce backwater effect
Secondary objectives - Improve fish passage; reprofile reach; narrow watercourse; raise natural bed level; naturalise bank side; marginal ecology improvement; in-stream diversity increase and naturalise flow regime Biodiversity enhancement and weir removal project.

Monitoring surveys and results

Edit project overview to modify the Monitoring survey and results.


Photographs pre-works

Lessons learnt

Edit project overview to modify the lessons learnt.


A difficulty may be in ensuring that flows in the complex Lower Colne system do not cause flooding elsewhere, as well as the access and cost of the proposed project. It had prior to the last LRAP update in August 2010, been mothballed.


Image gallery


ShowHideAdditionalImage.png


Catchment and subcatchment

Catchment

River basin district Thames
River basin Colne

Subcatchment

River name Colne Brook (from confluence with Alderbourne to confluence with Horton Brook)
Area category 10 - 100 km²
Area (km2)
Maximum altitude category Less than 100 m
Maximum altitude (m) 70
70 m
0.07 km
7,000 cm
Dominant geology Calcareous
Ecoregion Great Britain
Dominant land cover Improved grassland
Waterbody ID GB106039023010



Site

Name
WFD water body codes GB106039023010
WFD (national) typology
WFD water body name Colne Brook (from confluence with Alderbourne to confluence with Horton Brook)
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
Average channel gradient
Average unit stream power (W/m2)


Project background

Reach length directly affected (m) 500 m
0.5 km
50,000 cm
Project started 2008/01/01
Works started
Works completed
Project completed
Total cost category 50 - 100 k€
Total cost (k€)
Benefit to cost ratio
Funding sources FRM capital works

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 Barriers to fish migration, Flood risk management
Hydromorphology Quantity & dynamics of flow
Biology Fish
Physico-chemical Nutrient concentrations
Other reasons for the project


Measures

Structural measures
Bank/bed modifications Bank reprofiling, Weir removal
Floodplain / River corridor
Planform / Channel pattern Creation of pools and riffles
Other
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