Case study:Test and Itchen River Restoration Strategy

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Location: 50° 52' 56", -1° 23' 37"
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Project overview

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Status In progress
Project web site
Themes Environmental flows and water resources, Fisheries, Flood risk management, Habitat and biodiversity, Hydromorphology, Monitoring
Country England
Main contact forename Heb
Main contact surname Leman
Main contact user ID
Contact organisation Environment Agency
Contact organisation web site http://www.gov.uk/government/organisations/environment-agency
Partner organisations Natural England, local fisheries and riparian owners
This is a parent project
encompassing the following
projects
Old Station Beat restoration, River Test at Bossington
A River Restoration Centre Members site visit (June 2014) where Test and Itchen Project Officer, Heb Leman (Environment Agency), explained the aims of the restoration strategy. Photo © RRC

Project summary

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The Test and Itchen River Restoration Strategy is a collaborative project between the Environment Agency, Natural England, local fisheries and riparian owners.

Presently the SSSI status of the Test and Itchen is in unfavourable condition. This is due to historic dredging, the number of structures, industry and historic management. The aim of the Strategy is to collaboratively work with landowners to restore both rivers so that they reach favourable condition in the future.

Up to June 2014, approximately 2km has been improved by bed raising, narrowing and encouraging a change in management. Five restoration projects were completed in 2013 and a further six are planned for 2014.

Project 1: Old Station Beat restoration, River Test at Bossington (completed 2013)
At the Bossington Estate, the Environment Agency and Natural England have worked with Cain Bio-engineering to narrow the channel considerably (up to 40-60% in some sections) to restore a more natural river which has already led to significant improvement in the variety of river bed heterogeneity and in-channel habitats observed. The Estate have supported the project as they would like to attract anglers who prefer fly fishing in a more ‘challenging’ environment, than on other sections of the middle River Test, to offer this in the Test Valley. The total cost of the scheme was approximately £40,000 for 450m of restoration.

Project 2: River Test, Houghton Estate, close to Stockbridge (completed 2013)
The Houghton Club, one of the first fisheries to establish in England if not the world, has been open-minded. They agreed to modify historic bank management practices to enhance the channel and side channel scrapes have been created to reconnect the river to its floodplain in strategic areas. Selective channel narrowing has also taken place. Flooding in winter 2013/4 immediately showed the benefits of reconnecting the river with the surrounding land (which is designated SSSI). From a flood risk management perspective, holding water on this land prior to the river reaching Stockbridge was noted to have had a positive influence on flood risk reduction in the village. The project was jointly funded by the Environment Agency and the Houghton Estate.

Monitoring surveys and results

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Students at the University of Southampton are monitoring the Bossington Estate project, and are working with the Environment Agency on other sites too.

Lessons learnt

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The sections of river that have been restored demonstrate the contrasting approaches of contractors working on different sites (see Image Gallery). The extent of channel narrowing and restoration works take into account varying views of the landowners, the aspirations of the fishery and the requirement to improve the SSSI.


Image gallery


Backwater/ fish refuge on the Park Stream, Bossington Estate (tributary of the River Test) ©RRC June 2014
Channel narrowing and bed raising on the Park Stream, Bossington Estate (tributary of the River Test) ©RRC June 2014
Gravel infill shows the width of channel narrowing (40-60% of pre-restored channel) on the Park Stream, Bossington Estate (tributary of the River Test) ©RRC June 2014
Clean gravels and excellent spawning habitat after channel narrowing on the Park Stream, Bossington Estate (tributary of the River Test) ©RRC June 2014
Post channel narrowing (looking upstream) on the River Test, Houghton Club estate ©RRC June 2014
Post channel narrowing (looking downstream) on the River Test, Houghton Club estate ©RRC June 2014
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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
Works started
Works completed
Project completed 2015/03/31
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 Environment Agency/ Geodata/ Atkins
Stakeholder engagement and communication Environment Agency
Works and works supervision
Post-project management and maintenance
Monitoring Southampton University



Reasons for river restoration

Mitigation of a pressure Barriers to fish migration, Flood risk management, Impoundments (not hydropower), Land drainage, Riparian development
Hydromorphology Channel pattern/planform, Continuity for organisms, Continuity of sediment transport, Freshwater flow regime, Quantity & dynamics of flow, Width & depth variation
Biology Fish, Invertebrates, Macrophytes
Physico-chemical
Other reasons for the project


Measures

Structural measures
Bank/bed modifications Bed raising
Floodplain / River corridor Floodplain reconnection
Planform / Channel pattern Channel narrowing
Other Fish habitat restoration
Non-structural measures
Management interventions More sensitive channel maintenance
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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