Case study:Reconnecting the Rivers

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


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


Location: 52° 0' 20", -3° 15' 43"
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 In progress
Project web site http://www.wyeuskfoundation.org/projects/reconnecting.php
Themes Environmental flows and water resources, Fisheries, Habitat and biodiversity, Land use management - agriculture, Land use management - forestry, Monitoring, Water quality
Country Wales
Main contact forename Stephen
Main contact surname Marsh-Smith
Main contact user ID
Contact organisation Wye & Usk Foundation
Contact organisation web site http://www.wyeuskfoundation.org/
Partner organisations
Parent multi-site project

WHIP , pHish , UP! , Leader+ , Lugg & Arrow, Radnor Foal

This is a parent project
encompassing the following
projects
No
Project picture

Project summary

Edit project overview to modify the project summary.


Our first walk over survey of the upper Wye (1995/6) showed that over 50% of all available spawning habitat for salmon (by area) and over three quarters of trout spawning habitat was barred to ascending fish. A combination of neglect and poor regulation had allowed weirs, badly designed crossing points and road culverts to be built without the requirement for free passage of fish. These were the main culprits but huge debris dams had also formed on an alarming number of tributaries, completely sealing off hundreds of kilometres of essential spawning and nursery habitat. For salmon this was disastrous and the main cause of their decline, particularly the loss of the Lugg and its tributaries in the 1980s.

Small populations of brown trout remained above the blockages but the larger main channel residents, which provided the bulk of the egg deposition, were prevented from reaching the ideal (smaller) sized tributaries. The extent of the decline of brown trout as indicated by juvenile densities was even greater than that of salmon in the Wye by 1996.

Between 1996 and 1997 the Foundation embarked on a programme to reopen the tributaries of the upper Wye. The experience of the Tweed, North Esk and elsewhere showed that this is the single most cost effective way of increasing fish populations. The programme took two years, including surveying, and reopened 132km of salmon and 330km of trout spawning areas. Since then, the work has continued and as of 2013, there are just a few sites on the lower Usk, Wye and Lugg that require fish passes.

After this initial effort, the Foundation has continued opening or reopening Wye and Usk streams and rivers in the projects: WHIP , pHish , UP! , Leader+ , Lugg & Arrow, Radnor Foal and ART/Defra. The current and historical situations are detailed on the maps below which show the extent of the Wye and Usk catchment upstream that was blocked to migrating fish in 1972.


THE LUGG & ARROW

The Lugg and Arrow (the Wye's largest tributary system) had numerous barriers, built in the 18th and 19th centuries to control flooding and erosion, and to provide a water supply for agriculture and milling. Until the early 1980s, the catchment was accessible enough to enable up to 3,000 salmon redds to be recorded in a winter. However, in 1982 the Leominster Flood Alleviation Scheme sealed off the Lugg and the run dwindled to a few persistent pairs of salmon. This was partially corrected with a modern Larinier fish pass built at Hampton Court in 2003 and with two passes at Leominster in 2004.The next phase was to secure full access over the historic weirs and this will be completed in 2013.


USK

In 2004 we turned our attention to the Usk and found that while the river above Brecon is mainly unobstructed, the catchment from Brecon to Abergavenny is as bad as on the upper Wye in 1995 with every major tributary having at least one serious obstruction. Our tour de force was the construction of a fish pass in 2006 on the Cynrig – a stream that collects its rainfall from the steep slopes at the top of the Brecon Beacons.

Milestones in improving Wye and Usk fish access:

• 1996/7 Upper Wye Access Project.

• 2000 Flood washes out Skenfrith weir, Monnow

• 2003 pHish project - 7 fish passes.

• 2003 Hampton Court fish Pass opened R Lugg by EA Wales.

• 2004 Lugg Flood alleviation scheme fish passes (EA Wales).

• 2004 UP! Project: Cilieni Weir removed.

• 2006/8 Lugg and Arrow: 12 fish passes completed.

• 2006 Cynrig fish pass completed and weir removed Menasgin.

• 2008 Osbaston Fish Pass (Monnow) and lower Arrow passes completed.

• 2010 Four more fish passes completed on Arrow to take fish above Kington. Three Lugg fish passes modified by EAW below Kingsland. Modifications and removals on the Garren.

• 2011 EA Wales breaches and removes the weir at Kentchurch, opening up a huge spawning area on the Monnow system as a result.

• Weirs lowered on the Afon Lwyd (Usk tributary)

• 2011 Further improvements to upper Lugg and Arrow access with 8 more fish passes.

• 2012 Easements completed at Ffrwd, Berthin, Rhyd Y Meirch (Usk)

• 2013 Passes at Downfield and Mahollam (Arrow) completed and temporary easement at Dayhouse (Lugg).

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


ShowHideAdditionalImage.png


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 1995/01/01
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 Barriers to fish migration
Hydromorphology
Biology
Physico-chemical
Other reasons for the project


Measures

Structural measures
Bank/bed modifications Creation of fish passes, Removal of obstructions to flow
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