Case study:Langford Lakes project

From RESTORE
Jump to: navigation, search
0.00
(0 votes)


To discuss or comment on this case study, please use the discussion page.


Location: 51° 8' 11", -1° 57' 11"
Edit location
Loading map...
Left click to look around in the map, and use the wheel of your mouse to zoom in and out.


Project overview

Edit project overview
Status Complete
Project web site
Themes Economic aspects, Flood risk management, Land use management - agriculture, Social benefits, Spatial planning
Country England
Main contact forename Alasdair
Main contact surname Maxwell
Main contact user ID
Contact organisation Environment Agency
Contact organisation web site http://www.environment-agency.gov.uk
Partner organisations Wiltshire Wildlife Trust, Natural England, Wild Trout Trust
Parent multi-site project
This is a parent project
encompassing the following
projects
No
River Wylye, Langford Lakes restoration

Project summary

Edit project overview to modify the project summary.


This area comprises a series of large lakes with the River Wylye, a chalk stream, flowing through the centre of them. Langford lakes and the River Wylye are renowned for their popularity for angling but fish populations have declined over recent years. In an attempt to trap sediment and diversify flow, a number of natural materials have been introduced to the stream. Creation of a V weir.

Monitoring surveys and results

This case study hasn’t got any Monitoring survey and results, you can add some by editing the project overview.

Lessons learnt

This case study hasn’t got any lessons learnt, you can add some by editing the project overview.


Image gallery


P8150201.JPG
P8150204.JPG
P8150206.JPG
ShowHideAdditionalImage.png


Catchment and subcatchment

Catchment

River basin district South West
River basin Hampshire Avon

Subcatchment

River name Wylye (Middle)
Area category 100 - 1000 km²
Area (km2)
Maximum altitude category 200 - 500 m
Maximum altitude (m) 247
247 m
0.247 km
24,700 cm
Dominant geology Calcareous
Ecoregion Great Britain
Dominant land cover Arable and Horticulture
Waterbody ID GB108043022550



Other case studies in this subcatchment: Wild Wylye Phase 1


Site

Name Steeple Langford
WFD water body codes GB108043022550
WFD (national) typology Low, Medium, Calcareous
WFD water body name Wylye (Middle)
Pre-project morphology Single channel, Straight, High width:depth
Reference morphology Sinuous, Pool-riffle
Desired post project morphology
Heavily modified water body No
National/international site designation EU - Special Area of Conservation
Local/regional site designations
Protected species present No
Invasive species present No
Species of interest
Dominant hydrology Quick run-off, Groundwater
Dominant substrate Bedrock, Cobble, Gravel
River corridor land use Extensive agriculture, Woodland
Average bankfull channel width category 5 - 10 m
Average bankfull channel width (m)
Average bankfull channel depth category 0.5 - 2 m
Average bankfull channel depth (m)
Mean discharge category
Mean annual discharge (m3/s) 0.3
0.3 m³/s
300 l/s
Average channel gradient category
Average channel gradient
Average unit stream power (W/m2)


Project background

Reach length directly affected (m) 1000 m
1 km
100,000 cm
Project started 2002/10/01
Works started
Works completed 2002/10/01
Project completed
Total cost category
Total cost (k€) Unknown
"Unknown" is not a number.
Benefit to cost ratio
Funding sources Wiltshire wildlife trust, Natural England, Environment Agency

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 Quantity & dynamics of flow, Connection to groundwaters, Continuity of sediment transport, Continuity for organisms
Biology Fish: Disturbance-sensitive species, Invertebrates: Disturbance-sensitive species
Physico-chemical Nutrient concentrations
Other reasons for the project Flood risk management


Measures

Structural measures
Bank/bed modifications Planting, Sediment trap building, Morphological diversification, Diversification of in-channel features, Weir construction
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
http://publications.environment-agency.gov.uk/pdf/GESW0910BSTR-E-E.pdf WFD Status for Wylye - See P. 1355.
http://www.therrc.co.uk/rrc case studies1.php?csid=30 River Restoration Centre Case Study

Supplementary Information

Edit Supplementary Information

RRC Visit Notes (2002):

Most of the examples of techniques in this river have only just been put into place (the official opening of the site was 28th September 2002). It is therefore, too early to establish which are likely to provide answers in terms of best practice and whether the increase in channel diversity will have a long term benefit for fisheries objectives.

Some concerns were raised during the site visit about the use of the v weir in this particular situation and it remains to be seen how successful/sustainable this will be compared to the more ‘natural’ diversity initiatives using on site materials over the longer term.

The faggots and pegs appear already to have trapped some sediment behind them. They are, however, very experimental and their height, in this case (approx 40-50cm), may ultimately be most critical to their long term success. Nevertheless they may provide a possible alternative to places where toe boarding or similar structural support has been used along other rivers.

This is an excellent site for viewing and discussing a range of techniques, and evaluating their effectiveness and suitability along chalk streams and elsewhere.