SuDS Case Study – Project Red Dragon, RAF St Athan

SuDS Case Study – Project Red Dragon,
RAF St Athan
Tony Kirby, Arup
16th September 2008
Site Location
Project Red Dragon – Overview
•£80M Integrated Fast
Jet maintenance facility
for DARA
•Lead Consultant – Arup
•Principal Contractor –
Laing O’Rourke
•Construction 20022004
•Specific requirements
for surface water
attenuation
•Site area ~ 25Ha
Site Location Plan
Ammunition store
exclusion zone
Surface Water Requirements
• Peak flow attenuation (1 in 30 year) –
10,000m3
• Emergency shut-off facility for hangar
sprinkler activation
• Flexibility for future facility extension
• Hydrocarbon removal requirements
• No permanent open water bodies
(birds and planes don’t go together)
• Tanked systems for specialist
facilities
Constraints
• Space – Ammunition Exclusion
Zone
• Attenuation had to be provided offline
• Proximity of existing services
• Integration of hangar sprinkler
system requirements
• Hazardous flows from specialist
areas
• Interceptor location and size
SuDS System Operation
Paint
Petrol
Interceptor
Hangars
Chamber with
flow control
orifice
Site – 25 Ha
To Receiving
Watercourse
</= GFR
Chamber with
actuated shutoff valve
Attenuation Basin –
10,000m3
Surface Water
Overflow (storage)
Route to outfall after
storm passes
Surface Water
Flow
Surface Water Management Train
PREVENTION
CONVEYANCE
CONVEYANCE
SOURCE CONTROL
SITE CONTROL
REGIONAL CONTROL
To watercourse
or GWT
To watercourse
or GWT
To watercourse
or GWT
Maintenance and Performance
• DARA responsibility
• No significant issues during
design
• Basin has performed well in
storm events and a large
aircraft fuel spillage
• Maintenance limited to grass
cutting and emptying the
interceptor
• Automated systems allow rapid
flow containment
Summary – RAF St Athan
• Cost effective solution
• Dual purpose SuDS facility
• Maintenance considered easier than underground storage
options
• Crucial to RAF operations and EA discharge requirements
• System has functioned in a storage and emergency shut-down
mode in operation
Moving Forward
• Historically there have always been issues relating to Adoption
and Maintenance
• Things are moving in the right direction but still easier to
implement on private developments
• DCWW are actively supporting SuDS solutions and seeking sites
for their implementation
• Need to respond to Codes – e.g. Code for Sustainable Homes
(CfSH)
• EA restrictions on discharge and promotion of SuDS for majority
of sites in Wales
Heol-y-Coed, Rhiwbina
• Flooding problems with DCWW
surface water sewer
• 170m3 of flooding
• DCWW seeking to retro-fit
SuDS system to attenuate flows
in design event – 1 in 30 year
• Preferred solution is Stormcell®
due to limited space
• Product is approved by DCWW
and a Wavin system is currently
being trialled
• Support from LA with respect to
additional positive drainage