Case study:Louds Mill (Downstream)m Enhancement

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


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


Location: 50° 42' 44", -2° 24' 49"
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 Environmental flows and water resources, Fisheries, Habitat and biodiversity, Hydromorphology
Country England
Main contact forename Aly
Main contact surname Maxwell
Main contact user ID User:Alymaxwell
Contact organisation Environment Agency
Contact organisation web site
Partner organisations
Parent multi-site project

Case_study:River Frome Rehabilitation Plan

This is a parent project
encompassing the following
projects
No

File:1b Louds Mill Project Record.pdf

Project summary

Edit project overview to modify the project summary.


The reach downstream of Louds Mill was an over wide channel with little marginal vegetation and poor in channel bed morphology. During low flows the river was spread over the whole width of the channel leading to a shallow river. Spawning potential in the reach were limited due to compacted and over silted gravels. There was also very little cover and in channel structure provided by tree and in channel woody debris.

The River Frome Rehabilitation Plan states the main proposals to improve the SSSI condition and WFD objectives of unit 1b and to incorporate as part of the Louds Mill Enhancement were to: a) reprofile banks (to narrow the low flow channel and improve the marginal zone b) to reprofile river bed (to clean the gravels of silt break its compacted nature – improving spawning potential) c) introduce large woody debris to the reach (d) new riparian tree planting (willow whips to be inserted into the bank edges and soft margins at key locations.

Monitoring surveys and results

Edit project overview to modify the Monitoring survey and results.


Pre works electro fishing was complete. This is due for repeat in 2015

Lessons learnt

Edit project overview to modify the lessons learnt.


The technique of installing Large Woody Debris at this site involved digging a trench securing up to a third of the limb in the trench with the remaining in the channel. By using the thicker end of the limb in the trench it left only the thinner branches in the river.

Ideally the wood shoul dbe as large as possible when in the river to ensure it will be long lasting and have as big an impact on the flows lcoally as possible.


Image gallery


ShowHideAdditionalImage.png


Catchment and subcatchment

Catchment

River basin district South West
River basin Dorset

Subcatchment

River name Frome Dorset (Lower) & Furzebrook Stream
Area category 100 - 1000 km²
Area (km2)
Maximum altitude category 200 - 500 m
Maximum altitude (m) 223
223 m
0.223 km
22,300 cm
Dominant geology Calcareous
Ecoregion Great Britain
Dominant land cover Arable and Horticulture
Waterbody ID GB108044009690



Other case studies in this subcatchment: 2e Lower Woodsford River and Floodplain Enhancement, Bockhampton Enhancement, Hurst Bridge (downstream), Lower Bockhampton, Lower Woodsford, Martins River Island, Moreton Channel Gravel Reprofiling, North Channel Upper Reach, River Frome Rehabilitation Plan, Unit 1b - Long Bridge to Downstream of Louds Mill... further results


Site

Name
WFD water body codes GB108044009690
WFD (national) typology
WFD water body name Frome Dorset (Lower) & Furzebrook Stream
Pre-project morphology
Reference morphology
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) 150
150 m
0.15 km
15,000 cm
Project started 2013/01/01
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 Over-wide channel, poor morphology, Channel pattern/planform, Width & depth variation
Biology Silted gravels
Physico-chemical
Other reasons for the project Poor riparian vegetation


Measures

Structural measures
Bank/bed modifications Bank reprofiling, Re-profiling, Cleaning of spawning gravels, Introducing large woody debris, Tree planting, Marginal planting
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

Edit Supplementary Information