September 2013
As part of The MGSDP in September 2009, Scottish
Water appointed Design Consultants MWH to
undertake a drainage area plan and model for the
Shieldhall
catchment
which
provided
an
understanding of how and why areas flood and where
the catchment did not meet environmental
requirements.
Shieldhall Strategic Tunnel
How the solution was identified…
The MGSDP
The Metropolitan Glasgow Strategic Drainage
Partnership (MGSDP) is a partnership formed by
organisations involved with the operation of the
sewerage and drainage network within the Greater
Glasgow area.
Scottish Water, Glasgow City Council,
Canals, South Lanarkshire Council, Clyde
URC,Scottish
Enterprise
and
the
Environment Protection Agency (SEPA)
MGSDP.
Scottish
Gateway
Scottish
form the
Scottish Water is responsible for the sewerage
network; Glasgow City Council and South Lanarkshire
Council are responsible for roads drainage,
watercourses and flood risk; Scottish Canals is
responsible for the canal network and SEPA is
responsible for water quality and flood advice.
Scottish Enterprise and Clyde Gateway URC
have roles to consider economic development issues
and their impacts.
The MGSDP objectives are:
• Flood risk reduction
• River water quality improvements
• Enabling economic development
• Habitat improvement
• Integrated investment planning
The long term vision
The MGSDP 2060 Vision is to transform how the city
thinks about and manages rainfall to end uncontrolled
flooding and improve water quality.
The realisation of this vision will provide the flexibility
to respond to other changes in the city and help make
Scotland a world leading Hydro Nation.
A meeting was held in January 2011, which confirmed
what needed to be done with stakeholders from
Scottish Water, SEPA and local authorities. This
assessment highlighted various issues within the
catchment in terms of flooding areas, asset
deficiencies, aesthetic deficiencies and environmental
deficiencies leading to water quality failures.
Options were then developed (as shown in the table)
that would resolve the catchment needs, these were
then tested in the hydraulic model taking into account
the following issues:
• Health and Safety issues
• Hydraulic Engineering
• Land ownership
• Environmental issues
• Traffic Sensitivity
• Topography
• Geological / Geotechnical / contaminated
land issues
• Access for construction, operation &
maintenance
• Surface water flooding
• Location of known buried services
• Capital costs
Value Management (VM)
The Route
The Value Management Mission Statement is: “The
Optimum solution is the most strategic solution that
provides the lowest Net Present Value (NPV) at
acceptable risk".
Following the agreement of the tunnel as the best
option to resolve the needs, further engineering
studies were undertaken in early 2012 to establish the
most feasible and effective route.
Through a cross party project steering group, three
tunnel options were identified for more detailed
consideration to develop workable solutions and
clarify potential risks. The options were then
presented for a Value Management review to allow
the identification of the most technically feasible and
cost effective solution.
This process provided for a staged evaluation of
needs and appropriate options carried out by SW’s
delivery team in partnership with programme
stakeholders. For the purpose of this project under the
VM process was consolidated to one formal VM
meeting to agree the optimum solutions to be taken
forward to feasibility development stage.
The Tunnel option was selected as it was the best
value solution. It was also selected as it is a gravity
solution with minimal on-going maintenance costs, the
majority of the works will be tunnelling through open
parkland and will require less disruption to the public
during construction than the alternative solutions.
The alternative solutions required the construction and
maintenance of an 11,000m3 offline tank, a 1.3km
tunnelled outfall to the River Clyde, a new Kinning
Park Pumping Station, wet well and 5km rising main.
The alternative solution also required major
engineering works around Hampden Park and key
routes within the City Centre that would cause
significant disruptions to the public, and there would
be significant costs likely associated with service
diversions.