White Cart Water Flood Prevention Scheme
The problem…
The White Cart Water has
caused
significant
flood
damage
to
homes and
businesses in the south side of
Glasgow. This normally shallow
river can rise very quickly. More
than twenty large floods have
occurred since the early
twentieth century. In 1984 over
five hundred homes were
flooded
and
personal
possessions destroyed.
The solution…
Wh
i te
The implementation…
Ca
rt
GLASGOW
BARRHEAD
A
se
ou
h
d
ul
B
n
ur
Kittoch Bridge
Kitt
Flooding on Millbrae Crescent
Flood storage area
E
1,710 residential properties at risk of flooding
40 businesses at risk of flooding
20 significant floods in last 100 years
Last significant flood in 1990
Flood events in January 2005 and October
2008 were very close to flooding property
Cost of flood damage greater than £100m if
nothing done
Blackhouse
Main rivers
r
Wetlands
Kirkland Bridge
Re-meandered
channel
Glasgow
Location of principal components of project
The catchment scale solution comprises three online flood storage areas
and flood defence walls. The storage areas reduce river flows by up to 45%
and result in 15% less flood defences and a reduction in wall height of over
one metre in places thereby reducing the environmental and visual impact.
Actual flood defence height at Spean Street
Predicted Flood Outline – 0.5% Annual Probability Flood Event
hW
a te
EAST KILBRIDE
Flood defences
oc
rt
Ca
Key issues
er
at
W
n
ar
Dam
i te
Wh
KEY
Page 1
The implementation of the scheme was carried out over two
phases. Contracts were completed by Carillion and
VolkerStevin and result in those properties currently at risk
being protected from the current 0.5% annual probability
event.
Kirkland Bridge flood storage area
The provision of flood storage is an
environmentally sustainable method
of flood risk management for Glasgow
whilst providing much wider benefits.
A significantly higher wall would have been
required if no flood storage was provided
The largest vortex flow controls in the world were installed at each of the
flood storage areas to reduce flows in the flood risk areas. They have no
moving parts and are passable by fish and mammals. The provision of
ledges through the culverts ensure that mammals can safely pass through
the dams. In addition the vortex flow controls minimise the frequency of
inundation and allow the land upstream to remain in agricultural use.
Spean Street flood defence wall and planting
www.whitecartwaterproject.org
White Cart Water Flood Prevention Scheme
Contract 1: Flood Storage Areas
Contractor: Carillion
Contract 2: Flood Defences
Contractor: VolkerStevin
Contract 1 comprises the construction of the three flood
storage areas. The contract started in February 2008 and
was completed in 2011.
Contract 2 comprises the construction of 4.5 kilometres of
flood walls, six pumping stations and the raising of two
bridges together with significant environmental works in a
very densely developed urban environment. The contract
commenced in October 2008 and was completed in 2011.
The majority of materials required to construct the earth
embankments were sourced from on site borrow pits rather
than importing. Excavated rock was reused on site in
gabions and roads to avoid off site disposal and the need to
import materials.
This phase presented a number of challenges including the
management of invasive species, contaminated land,
dealing with numerous utilities and minimising the impact
on an important wildlife corridor as well as keeping the
several hundred affected residents fully informed.
As well as the major civil engineering works, extensive
environmental works were carried out including the
creation of new wetland habitat, re-meandering a
straightened river channel and the creation of new habitats
for birds, otters and badgers and ensuring fish and
mammals could pass through the dams unharmed.
The recycling and re-use of materials was important with
haul road materials used to create mammal ledges and as
scour protection to newly formed riverbanks.
River banks seeded with native species
Boulders and baffles in culvert to enable passage by fish
Kirkland Bridge – artificial nesting wall used by over a dozen nesting Sandmartin pairs
Invasive species were prevalent
Millbrae Crescent garden reinstatement
• 4.5km flood defence walls and
embankments
• Six underground pumping stations
• Two raised footbridges
• Redevelopment of existing park
• Embellishment of gardens and
allotments
• 1,000 trees planted
• Creation of artificial habitats for birds,
bats and otters
• 20% recycled materials
• Consultation was essential
Collecting seed from existing wetland
Key
KeyFacts
facts
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•
•
•
•
•
Kirkland Bridge – wetlands and wet woodland tree planting
Page 2
Key
KeyFacts
facts
Catchment scale solution
2.6Mm3 flood storage
9 hectares species rich wetlands
180,000m3 locally won embankment fill
6,000 trees and scrub planted
Post construction environmental surveys
and monitoring
Completed flood defences at Tantallon Road
www.whitecartwaterproject.org