Case study:Goshen Weir removal project, River Roch, Bury
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- 1 Project overview
- 2 Image gallery
- 3 Catchment and subcatchment
- 4 Site
- 5 Project background
- 6 Reasons for river restoration
- 7 Measures
- 8 Monitoring
- 9 Additional documents and videos
- 10 Additional links and references
- 11 Supplementary Information
|Project web site|
|Themes||Fisheries, Flood risk management, Habitat and biodiversity, Hydromorphology|
|Main contact forename||Gary|
|Main contact surname||Morris|
|Main contact user ID||User:Gjmorris|
|Contact organisation||Environment Agency|
|Contact organisation web site||http://http://www.environment-agency.gov.uk/|
|Partner organisations||River Restoration Centre, APEM Ltd, Irwell Rivers Trust|
| This is a parent project
encompassing the following
Goshan weir on the River Roch in Bury was severely constraining the river corridor and restricting fish passage upstream. The weir removal was the largest attempted at the time, approx 1 km downstream of Gigg lane weir that had previously collapsed.
The weir was carefully removed by Environment Agency operations delivery operatives. Some consultancy pre-app work was undertaken by APEM that included the removal strategy to take out middle 60% and leave in the bankside lengths of the weir. This was to try and centralise the flow and take pressure of the river banks, especially the outer right hand bank.
This is one of the larger weirs that has been removed as part of the Irwell WFD ‘Good ecological potential’ project.
Monitoring surveys and results
Five monitoring methods
Expert opinion and observation drawing upon in-house geo-morphological expertise
Habitat mapping survey
Fixed point photography survey (manually taken and via time lapse cameras)
Invertebrate surveys (planned, as of May 2014, as easement works are currently being undertaken on Kirklees Brook by Irwell Rivers Trust)
Fisheries survey (planned, as of May 2014, as above)
The results are plain to see. Cumulative benefits.
The video footage shows how the angle of the weir originally directs flow to the inside of the bend. Once removed a more natural flow to the outer bend is established, with large sand and gravel deposits on the inner bend quickly burying the weir remains. The river quickly thins its width at the weir site. This also happened at the Gigg Lane weir site further upstream. One difficulty highlighted by this work is knowing just where to go to collect good data. It became evident that a large amount of erosion occurred at the top of the upper weir, an area that we were not monitoring. By focussing on the events close to our own intervention we saw little of what happened further upstream.
Problems with camera theft for time lapse work. Cameras for the Irwell Rivers Trust considrered disposable and data valued more than equipment.
Catchment and subcatchment
Select a catchment/subcatchment
Cost for project phases
Reasons for river restoration
Hydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Additional documents and videos