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Restoration of River Cennen, south-west Wales(© EAW)
The River Cennen is a valuable spawning tributary of the River Towy, Wales's finest
sea-trout river. Since the late 1980s a large stretch of this river has been degraded due
to bank erosion - the result of removal of alder trees which used to line both banks.
Heavy grazing by sheep and cattle prevents seedlings from maturing. Before restoration
work began, the density of spawning redds had fallen to one tenth of the value recorded in
the 1970s.
This picture shows the intersection of the restored stretch of river bank with the
alder-lined region where natural erosion-resistance is provided by the tree roots.The
gravel in the foreground was strewn over the fields by heavy spates in the winter of
1998/99.
The willow spiling should help to stabilise the banks once the willows take root.
A stock-proof fence now keeps cattle out of the river, and long willow stakes inter-woven
with thinner willow branches and then back-filled with soil provide an erosion-resistant
edging. This technique is known as willow spiling.
After just a few months the willow spiling begins to shoot: roots are already growing into
the back-filled soil. In a couple of years time these roots will bind the banks firmly and
create a strong, erosion-resistant edge to this very active spate river. (In low water the
Cennen averages less than half a metre deep, but it can rise a further two metres during
very wet weather.)
Project aim
The aim of the restoration project is to re-stabilise the banks and provide a buffer strip
of dense vegetation to limit the influx of silt and farm chemicals into the river. Once
the gravels become more stable, it is intended to add boulders to the stream to
create local refuges where young trout and salmon can shelter out of the strong current
during spates and away from predatory birds during low flows.
Funding Partners
Environment Agency Wales
Eifion Jones, Glancennen Farm
Carmarthenshire Fishermen's Federation
The project team includes:
Environment Agency Wales
British Trust for Conservation Volunteers
Environment Task Force members under the New Deal Initiative Waterside UK
Consultation
Before work started, the Countryside Council for Wales was consulted, since the River Towy
(but not its tributary the Cennen) is a candidate Special Area of Conservation; this
European designation is proposed to protect the twaite shad that spawn in the Towy as far
up river as Llandeilo.
Results
The aim is to restore juvenile trout and salmon densities to what they were in the 1970s.
A juvenile salmonid monitoring programme will record the results of this project.
Other habitat restoration initiatives in south-west Wales
This project is one of several carried out on the spate rivers of south-west Wales. Other
initiatives include habitat restoration work on the rivers Aeron, Teifi, Rhosmaen Dulais
and Marlais.