Case study:Creamery Weir fish barrier easement

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Location: 54° 52' 23", -4° 4' 5"
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Project overview

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Status Complete
Project web site
Themes Fisheries, Habitat and biodiversity, Hydromorphology
Country Scotland
Main contact forename Rob
Main contact surname Mitchell
Main contact user ID User:Robmitchell
Contact organisation RAFTS
Contact organisation web site http://www.rafts.org.uk
Partner organisations Galloway Fisheries Trust, SEPA
Parent multi-site project
This is a parent project
encompassing the following
projects
No
Creamery Weir before removal

Project summary

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This project aimed to overcome a barrier to migratory fish to allow access to over 10km of habitat. A feasibility and options report led to the selection of removal as a preferred option. Design of the removal option took place in Winter 2015/2016, and the removal process began in August 2016 (completing within one month).

There were significant volumes of sediment that had accumulated behind the weir so the project had a strong element of hydromorphological restoration, as well as enabling fish passage. Any large stone located within the sediment was reused to create rock steps in the new channel, with the remainder being disposed of in line with waste regulations. These also acted as bed checks to guard against upstream incision, although in reality plentiful bedrock outcrops also served this purpose.

A disused sluice gate downstream of the weir site was also removed to ensure effective fish passage.

Finally, the left bank of the river channel is relatively steep and a public road is situated at the top of it. In order to stabilise this bank and guard against erosion, mixed seed-impregnated erosion protection matting has been installed.

Monitoring surveys and results

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Removal took place relatively recently, and so monitoring has yet to be undertaken. Site visits are planned for early 2017, and in the longer term Galloway Fisheries Trust will carry out electrofishing surveys upstream of the site in order to compare the data with pre-works survey results.

Lessons learnt

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It was difficult to identify a cost-effective and reliable method of determining the original bed level beneath significant amount of stored sediment upstream of the weir. The final decision was to remove the sediment in a careful and 'staged' manner, ensuring that hydromorphological expertise was on site to determine the point at which the original bed level was reached. This made it difficult to estimate clear costs of sediment disposal, but estimates proved relatively reliable.


Image gallery


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Creamery Weir from downstream.jpeg
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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 2014/09/01
Works started
Works completed
Project completed
Total cost category
Total cost (k€)
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



Reasons for river restoration

Mitigation of a pressure
Hydromorphology Impassable barrier to migratory fish
Biology
Physico-chemical
Other reasons for the project


Measures

Structural measures
Bank/bed modifications Weir removal
Floodplain / River corridor
Planform / Channel pattern
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

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