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Pretty Nice Looking Drains
Is civil engineering a necessary encumbrance
involving considerable cost but no visible or
tangible benefit?Because it goes largely
unseen, engineering tends to matter to people
only when things go wrong and fail to function
properly. A tendency exists to commit the
minimum required resource to obtain the minimum
required result. As a consequence, marginal
infrastructure can result. We believe the way to
avoid costly and marginal infrastructure is to
aim for a result that people can appreciate, like
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Filter Drain with filter strip

• Surface runoff from road drains to median
• Runoff passes through grass vegetation planted on
  edge of filter drain, removing pollutants
• Stone medium slows and filters the water
• Larger rocks and variety planting adds to the
  aesthetic value while slowing the flow of water

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Filter Drain with filter strip
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Filter Drain with filter strip
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Grassed Swale
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Grassed Swale
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Infiltration Detention Basin
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Detention Basin
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Permeable Carpark
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Permeable Carpark

• Surface runoff from impermeable carpark surface
  drains over grass to filter drain
• Infiltration only achievable for small carpark
  areas or if highly permeable soils exist on site
• Otherwise, filter drain will treat and attenuate
  surface water before discharge

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The following slides illustrate the application
of SuDS principles to civil engineering designs
carried out by Chris Bakkalas team at Buro
Happold.
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Ballyshannon Model VillageFKL Architects
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A new Place
Place Location Identity
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Accommodation Place for Living

• 1 x 5 classroom primary school
• 1 crèche
• Village hall
• 4 commercial units
• Enterprise units
• 9 Office/ work units
• 1 stables building
• 128 houses

• Allotments
• Football pitch
• Age-specific playgrounds
• Bridle path
• Wetlands, ponds biodiversity habitats
• Kick around space
• Open green space

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Streetscape room walk, grow and drive
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Streetscape shaping topography to drain without
pipes
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Natural Effluent Treatment Systems

• A Proposed Reed Bed and Wetland System
• To provide full treatment for 500P.E from the
  Ballyshannon Model Village and tertiary treatment
  to 1000P.E from surrounding developments in
  Calverstown. It is proposed to achieve this
  through the use of a gravity fed natural
  treatment system having the benefit of increasing
  biodiversity habitats for many bird, animal and
  invertebrate species, in keeping with the rural
  aspect of the development.

Primary Treatment Settlement Tank Secondary
Treatment Horizontal Flow Reed Bed The primary
and secondary systems have been designed
according to the EPA Wastewater Treatment
Manuals, Treatment Systems for Small
Communities, Business, Leisure Centres and
Hotels Secondary and Tertiary Treatment
Integrated Constructed Wetland (ICW) The tertiary
system has been designed according to the ICW
concept developed by the National Parks and
Wildlife Service, Department of Environment,
Heritage and Local Government.
Reed Bed Wastewater Treatment Systems
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Very Low Maintenance

• Horizontal Flow Reed Bed and Integrated
  Constructed Wetlands
• Weekly
• - Log flow rates from continuous flow monitor to
  and from the wetland
• - Examine distribution pipes for blockages
• - Water level management and flow maintenance
• - Visual monitoring of final effluent,
  vegetation progress and initial fencing
• Monthly
• - Surface water quality monitoring of influent,
  effluent and receiving water course
• - Ground water monitoring
• Yearly
• - Maintenance of embankments
• - Sediment/sludge management

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The Village,CloughjordanSolearth Ecological
Architects
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Layout
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Boreens and meandering streams
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SOAKAWAYS
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Filter Drains
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Swales and Detention Ponds
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Paving over soft ground
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Traditional Drainage Systems

• (Traditional is a word whose meaning will
  change in the future)
• Aims
• Remove surface water from streetscape
  (conveyance)
• Reduce potential downstream flooding (storage)
• Remove heavy particulates and hydrocarbons more
  recent addition (treatment)
• Methods
• Road Gully Traps connected to an underground pipe
  network
• Attenuate stormwater on-site via underground
  tanks or ponds with discharge from site
  restricted via a hydrobrake or orifice plate etc
• Surface water from carparks and large road areas
  passing through a Catchpit and Petrol and Oil
  Interceptor

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Sustainable Drainage Systems (SuDS), or,
Sustainable Urban Drainage Systems (SUDS)

• Focuses decisions about drainage on the
  environment and on people
• Takes account of the quantity AND quality of
  runoff
• Takes account of the amenity value of surface
  water in the urban environment (work with
  Landscape Architects)
• Requires a philosophy shift from previous design
  techniques used
• Aim to mimic natural (greenfield) drainage
  processes, albeit in a controlled, engineered
  manner
• - Infiltration volume of infiltration should
  ideally match greenfield rates
• - Slow runoff
• - Runoff to pass through vegetation
• - Good water quality

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Sustainable Drainage Systems (SuDS)

• Surface Water Management Train
• - Source Control (street level)
• - Site Control (estate/developed site)
• - Regional Control (receiving waters local
  authorities)
• SuDS features also achieve the three main aims of
  the traditional drainage system, broadly
  summarised as
• Conveyance
• Storage
• Treatment

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SuDS Techniques

• Filter Strips and Swales
• Mimics natural drainage patterns surface flow
• Surface Runoff passes through vegetation, slowing
  and filtering the flow
• Can be designed to achieve conveyance,
  infiltration, storage and treatment
• Suitable for roads, carparks and small
  residential developments
• Very economical, however flow path may be easily
  blocked by parked cars, construction materials
  etc
• Filter Drains and Permeable Surfaces
• Encourages subsurface flow
• Contains permeable material below ground to
  convey and store surface water
• Provides treatment by slowing, filtering and
  storing the flow

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SuDS Techniques

• Infiltration Devices
• Subsurface Soakaways, infiltration
  trenches/filter drains
• Surface Swales, landscaped basins/fields
• Remain dry (except during heavy rainfall periods)
  allowing public use, such as playing fields,
  recreational areas, public open space etc
• Help to recharge groundwater, thereby mitigating
  development impacts on rivers and streams by
  maintaining base flows
• Detention Basins and Retention Ponds
• Basins are utilised during heavy rainfall to
  provide flood attenuation and can be incorporated
  to fulfill a number of SuDS aims such as
  treatment and infiltration
• Ponds retain water in dry weather, providing
  treatment and amenity value (with an allowance
  for flood attenuation) and include wetlands and
  lagoons

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Opportunities from SuDS

• Many engineers are used to treating surface water
  as a nuisance
• Chance to be seen as leading thinkers and
  designers for holistic drainage design
  quantity, quality and amenity
• Work closely with Landscape Architects
• - SuDS can play a vital role in the landscaping
  of a development. It is highly advantageous to
  work together early in the planning/design phase
  to understand the possibility of achieving common
  goals through SUDS.