Case study:Salisbury Avon Restoration Project: Difference between revisions
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|Project summary=The Hampshire Avon has historically been dredged, over-widened and impounded in many places due to past river management. This has led to a reduction in the river’s geomorphological processes, which has, in turn, led to a decline in the habitat quality and quantity throughout the reach. This decline, despite recent sympathetic management, has continued due to the lack of variation in channel form and flows, as well as riparian land use. | |Project summary=The Hampshire Avon has historically been dredged, over-widened and impounded in many places due to past river management. This has led to a reduction in the river’s geomorphological processes, which has, in turn, led to a decline in the habitat quality and quantity throughout the reach. This decline, despite recent sympathetic management, has continued due to the lack of variation in channel form and flows, as well as riparian land use. | ||
'''Description of Works''' | '''Description of Works''' | ||
This project focuses on two 750m reaches of the Hampshire Avon at Figheldean and West Amesbury, identified in the Strategic Framework for the Restoration of the River Avon (SFfRRA) as being in need of restoration for habitat quality. The restoration aims to return a more natural flow regime at the two sites, in order to promote natural bed scouring and increase riparian habitat for a variety of organisms. This will be achieved through: | This project focuses on two 750m reaches of the Hampshire Avon at Figheldean and West Amesbury, identified in the Strategic Framework for the Restoration of the River Avon (SFfRRA) as being in need of restoration for habitat quality. The restoration aims to return a more natural flow regime at the two sites, in order to promote natural bed scouring and increase riparian habitat for a variety of organisms. This will be achieved through: | ||
*the narrowing of over-widened channels to promote bed scouring and increase Ranunculus growth; | *the narrowing of over-widened channels to promote bed scouring and increase Ranunculus growth; | ||
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*introduction of woody debris to aid channel narrowing and create in-channel habitat for fish and invertebrates; | *introduction of woody debris to aid channel narrowing and create in-channel habitat for fish and invertebrates; | ||
*creation of gravel riffles to create fish spawning habitat and flow variation; | *creation of gravel riffles to create fish spawning habitat and flow variation; | ||
*tree planting for channel shading and to provide future woody | *tree planting for channel shading and to provide future woody debris; | ||
*riparian habitat creation/enhancement, such as scrape creation for invertebrate and bird life and bank re-profiling to reconnect the river to the floodplain (re-wetting wet woodland/pasture). | *riparian habitat creation/enhancement, such as scrape creation for invertebrate and bird life and bank re-profiling to reconnect the river to the floodplain (re-wetting wet woodland/pasture). | ||
Revision as of 10:17, 3 July 2013
This case study is pending approval by a RiverWiki administrator.
Project overview
Status | In progress |
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Project web site | |
Themes | Habitat and biodiversity, Hydromorphology |
Country | England |
Main contact forename | John |
Main contact surname | Rattray |
Main contact user ID | |
Contact organisation | Wiltshire Wildlife Trust |
Contact organisation web site | http://www.wiltshirewildlife.org |
Partner organisations | Environment Agency, Natural England, Wessex Water, Wiltshire Fishery Association |
This is a parent project encompassing the following projects |
Project summary
The Hampshire Avon has historically been dredged, over-widened and impounded in many places due to past river management. This has led to a reduction in the river’s geomorphological processes, which has, in turn, led to a decline in the habitat quality and quantity throughout the reach. This decline, despite recent sympathetic management, has continued due to the lack of variation in channel form and flows, as well as riparian land use.
Description of Works This project focuses on two 750m reaches of the Hampshire Avon at Figheldean and West Amesbury, identified in the Strategic Framework for the Restoration of the River Avon (SFfRRA) as being in need of restoration for habitat quality. The restoration aims to return a more natural flow regime at the two sites, in order to promote natural bed scouring and increase riparian habitat for a variety of organisms. This will be achieved through:
- the narrowing of over-widened channels to promote bed scouring and increase Ranunculus growth;
- re-meandering of channelized sections, through the creation of berms and the use of woody debris, to restore natural deposition/erosion processes;
- introduction of woody debris to aid channel narrowing and create in-channel habitat for fish and invertebrates;
- creation of gravel riffles to create fish spawning habitat and flow variation;
- tree planting for channel shading and to provide future woody debris;
- riparian habitat creation/enhancement, such as scrape creation for invertebrate and bird life and bank re-profiling to reconnect the river to the floodplain (re-wetting wet woodland/pasture).
Each restoration project completed will act as an example to future projects in the area. Through appropriate publi-cation and engagement this project will help to raise awareness of river restoration techniques and implementation on the River Avon catchment. Restoring natural functions to the river system will also increase the potential of the river to adapt to a changing climate in the future as part of a living landscape.
Monitoring surveys and results
Lessons learnt
Catchment and subcatchment
Edit the catchment and subcatchment details
(affects all case studies in this subcatchment)
Catchment
River basin district | South West |
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River basin | South Devon |
Subcatchment
River name | Avon |
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Area category | 10 - 100 km² |
Area (km2) | |
Maximum altitude category | 500 - 1000 m |
Maximum altitude (m) | 513513 m <br />0.513 km <br />51,300 cm <br /> |
Dominant geology | Siliceous |
Ecoregion | Great Britain |
Dominant land cover | Improved grassland |
Waterbody ID | GB108046004940 |
Site
Name | Hampshire Avon |
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WFD water body codes | |
WFD (national) typology | |
WFD water body name | |
Pre-project morphology | |
Reference morphology | Re-meandering |
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) | |
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Project started | |
Works started | |
Works completed | |
Project completed | |
Total cost category | 100 - 500 k€ |
Total cost (k€) | 286.470286.47 k€ <br />286,470 € <br /> |
Benefit to cost ratio | |
Funding sources |
Cost for project phases
Phase | cost category | cost exact (k€) | Lead organisation | Contact forename | Contact surname |
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Investigation and design | |||||
Stakeholder engagement and communication | |||||
Works and works supervision | |||||
Post-project management and maintenance | |||||
Monitoring |
Reasons for river restoration
Measures
Structural measures
| |
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Bank/bed modifications | Creation of gravel riffles to create fish spawning habitat and flow variation |
Floodplain / River corridor | Tree planting for channel shading and to provide future woody de-bris; |
Planform / Channel pattern | Re-meandering of channelized sections, through the creation of berms and the use of woody debris, to restore natural deposition/erosion processes; the narrowing of over-widened channels to promote bed scouring and increase Ranunculus growth. |
Other | |
Non-structural measures
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Management interventions | |
Social measures (incl. engagement) | |
Other |
Monitoring
Hydromorphological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
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Before measures | After measures | Qualitative | Quantitative |
Biological quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
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Before measures | After measures | Qualitative | Quantitative |
Physico-chemical quality elements
Element | When monitored | Type of monitoring | Control site used | Result | ||
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Before measures | After measures | Qualitative | Quantitative |
Any other monitoring, e.g. social, economic
Element | When monitored | Type of monitoring | Control site used | Result | ||
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Before measures | After measures | Qualitative | Quantitative |
Monitoring documents
Image gallery
Additional documents and videos
Additional links and references
Link | Description |
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Supplementary Information
Edit Supplementary Information