Cole Brochure
Cole Brochure
Cole Brochure
R ESTORA T
IO
RIVER
CT THE
JE O N
PR
The river Cole restored to its old course on the historic Wilts-Berks county boundary – photo; M Janes)
E S T O RA
R T
IO
Additional support was received from the Rivers Agency (Northern Ireland)
O
Photo: M Janes
demonstrates what can be achieved
in an urban environment.
The Skerne has been straightened and
enlarged to reduce flooding and to
RE
STORA
T The Future –The River Restoration Centre
IO
RIVER
After invaluable consultation with key UK institutions responsible for land and water management, RRP
CE
has been advised that it should continue to function as a UK wide catalyst for information and advice on
N
E TR
TH E
CONTACTS
For further information please contact:
River Restoration Centre. PO Box 126, Huntingdon, Cambs PE18 8QB. Telephone 01525 863341.
E-mail rrp@cranfield.ac.uk
Brochure design and map by Rob & Rhoda Burns / Drawing Attention 01438 871627. E-mail: robrhoda.graphic@ndirect.co.uk
RRP logo by Sign Design, Printed by Arca Press Ltd, Bedford
THE RIVER COLE
About the River Cole
Photo: M Janes
The River Cole runs through The National Trust owned Coleshill estate, NE of Swindon on the Oxon / Wilts border. It has
been extensively modified by man for a variety of reasons over the past 900 years, particularly milling. Originally the reach below
the mill was simply straightened, but more recently was considerably enlarged to safeguard agricultural production
and flood capacity. Above the mill the channel was realigned 200-300 years ago to form the present mill leat. This type of
historical management for milling, land drainage and agriculture is typical of many other rivers in the UK.
As a result, the ecology of such rivers has suffered.
The Objectives
• Restoration of the river and floodplain in terms of physical features, flood storage,
habitat diversity and visual appearance.
• Application of innovative restoration techniques and best management practice,
within a sustainable agricultural system.
• Furthering of knowledge and understanding of river restoration by monitoring
to a very high degree, and by practical demonstration of the results.
catchment gave the size and shape of a typical and sustainable river.
From old maps and documents it was possible to establish the upstream
pre-mill leat course of the river Cole. The ditch bypassing the mill was
identified as a remnant of the old course.
The river was reinstated on the original buried course by excavating a smaller
meandering channel and profiling the bed and banks to more natural shapes.
Downstream of the mill, mature trees were perched well above the bed of the
old channel, due to a dredging scheme carried about 25 years ago which
removed 1m of clay from the river bed. This general bed lowering also served
to reduce the water table in the adjacent floodplain fields.
New channel Here the bed level, water level and flood regime of 25 years ago were restored by:
The course of the new channel upstream of the mill is
based on old maps and visual interpretation.
This channel links into the remnant River Cole
•• Cutting a smaller channel 1.2 m above the bed of the old channel.
Meandering across the old channel keeping mature riverside trees.
to bypass the mill weir. The new course
now has ample energy gradient to
• Filling the old course whilst leaving deep backwater pools.
Map artwork: R & R Burns
sustain a small, self cleansing Although the restored channels initially looked barren, natural features are generating differen
faster flowing river. habitats. It will however, always be impossible to accurately define the exact natural state of t
river so it is essential to leave some scope for self-adjustment within the restoration
project design.
ourse
Restored dc
Re
sto l
meander re d r O
iv e r
Mill leat
Photo: M Janes
AT COLESHILL
Backwaters and
habitats Reedbed
Whilst much of the old river A small linear reedbed has
Cole was infilled, some parts been constructed and
were kept as backwaters to planted on a wide berm
provide a different habitat adjacent to the new course.
to the fast flowing, newly The reedbed is fed by an
restored course. agricultural field ditch with
a high nutrient content.
These areas are over 1m Although this feature has
deeper than the new river been designed as a habitat
(the meanders having been
Photo: M Janes
reedbed, it also offers some
cut at a higher level), and ‘buffering’ of the ditch
are important for fish, water before it enters
plants and invertebrates. the river.
Fritillary
meadow
Fritillary meadow
A small meadow of rare Snake’s Head
Fritillaries survives here but it has been
drying out over the past 25 years. An
adjacent field (previously arable) has been
New backwater re-sown with a meadow grass mixture and
an existing shallow gully has been linked
back to the river to restore seasonal flooding.
Both fields will be farmed as traditional
nt hay meadows.
the New meadow
replaces
arable crops
Arable
crops Riverbank Cliffs
ed
restor
ds
Floo
Photo: M Janes
Channel adjustment
In creating a different course for the River Cole
some natural adjustment was allowed for.
This gives the river the chance to form the small
irregularities present in all rivers, as well as the
more regular pool and riffles, vertical riverbank
cliffs and gravel beaches.
MONITORING AND BENEFITS
The Monitoring
Programme
A full background study was
carried out to make certain that
the river and the surrounding
area was thoroughly understood
before any plans were drawn.
This information will allow
comparisons to be made with the
changes resulting from the works.
A comprehensive monitoring
programme has been running since
the start of the project and will be
extended to cover at least four years
post-project.
Photo: M Janes
Early Results
• Flooding: The designed shallow flooding of grass
fields lets silt settle on fields, with less in the river.
• Landscape: River now a pleasure to see and hear; flower rich meadows
still to establish.
(photo; M Janes)
Wider Benefits
The knowledge and experience gained
means that others can be more
confident about organising, funding,
designing and implementing
future projects.
In addition, the project improves
Photo: M Janes