Case study:Salmons Brook River Restoration at Laymer Road
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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, Social benefits|
|Main contact forename||John|
|Main contact surname||Bryden|
|Main contact user ID|
|Contact organisation||Environment Agency|
|Contact organisation web site||http://www.gov.uk/government/organisations/environment-agency|
|Parent multi-site project|
| This is a parent project
encompassing the following
This stretch of river has been subject to a previous project undertaken by the Environment Agency’s predecessors the National Rivers Authority in 1994. This installed 5 small weirs and a toe boarding along a significant length of the river. These structures would now be seen as inappropriate due to the their impact on the morphology of the stream and the requirements of the Thames River Basin Management Plan. The proposal therefore is to removal the silt traps, regrade banks, meander river and remove the check weirs and toe boarding.
The Salmons Brook is an urban river running through Enfield, London. The river has large number of issues including water quality due to urban diffused pollution and physical modifications including weirs and hard banks. For this reason the catchment (water body) has been designated as Heavily Modified for urbanisation and flood protection in the Thames River Basin Management Plan with a target of getting the river into Good Ecological Potential by 2027. The section of river from the A10 (TQ3342994308) to Latymer Rd (TQ3389694053), has been identified as section which could be improved relatively significantly through relatively minor interventions. Once the river exists the A10 culvert it passes between 2 allotments with a small footpath running on top of the left bank. At the end of the allotments there’s a footbridge across the river where the left bank opens into a small recreation ground, with the right bank being a housing estate. The informal footpath follows the top of the left bank to Latymer Rd dividing the river from the a junior school.
The investigation needed to be completed and costed by April 2011. The consultants (whoever wins the work) will be required to undertake a detailed level survey of this stretch of river and develop options to remove these structures and restore the river to a natural morphology. The consultants should look to develop only in channel options as its not feasible to meander the channel – although regrading might be viable in some areas. Its believed that there should be two options produced 1) Complete removal or notching of the weirs, 2) replacement of the weir’s by a series of fixed gravel riffles. However if the consultants believe that there would be another viable option then they should fully investigate and present this. The consultants will also be required to investigate if the toe boarding can be removed as well.
Aspects to consider with the investigation include the reason for the installation (erosion control) of the structures and the future consequence of there removal on the surrounding areas. The consultants also need to consider cost of instillation as there is a limited budget available for installation and therefore a cost efficient solutions needs to be developed.
Monitoring surveys and results
Catchment and subcatchment
Select a catchment/subcatchment
Other case studies in this subcatchment: Alma Road Rain Gardens, Bury Lodge Wetlands, Enfield Town Park Wetlands, Glenbrook Wetlands, Grovelands Park Wetlands, Houndsden Road Rain Gardens, Laymer Road Silt Trap and Recreational Ground, Rewilding Enfield's Urban Rivers, Salmons Brook Flood Alleviation Scheme, Montagu Recreation Ground site, Salmons Brook at Grange Park
Cost for project phases
Reasons for river restoration
Hydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Additional documents and videos