SuDS illustrations

Steven Wade

Sustainable Drainage Systems (SUDS)

• Sustainable drainage is a an approach, which unlike conventional drainage:

- Replicate, as closely as possible, the natural flow pattern of a urban development site- Minimise the impact the site on flooding and pollution of rivers, streams and other water bodies- Manage water from

developments in a sustainable manner- Provide amenity/biodiversity

benefits

© All images in this presentation are copyright of the Environment Agency except where stated

SUDS Triangle

Rapidremoval

ofwater

MinimiseFlood Risk

Control Water Pollution

Urban amenity

&biodiversity

Traditional Urban drainage Sustainable Urban drainage

© SWIMMER

The effects of development on Water Quantity

An undeveloped catchment

40%Evapotranspiratio

n

25% Deep infiltration

25%Shallow

infiltration

10% Runoff

Ponding / storage

© All images in this presentation are copyright of the Environment Agency except where stated

The effects of development on Water quantity

A developed catchment with conventional drainage

60% Runoff

10% Shallow infiltration

5% Deep infiltration

20%Evapotranspiration

© All images in this presentation are copyright of the Environment Agency except where stated

How do they operate? The SUDS Management Train

Source Control

Site Controls

Regional Controls

Watercourse

Soakaway / InfiltrationSwalesFilter drains / Filter stripsPorous/permeable surfaceBio-retention areas

Storage/attenuationDetention BasinsExtended DetentionInfiltration Basins

SUDS Technique

Retention PondsWetlandsBasins

Treatment Level

© All images in this presentation are copyright of the Environment Agency except where stated

The management train

© All images in this presentation are copyright of the Environment Agency except where stated

SUDS Sustainable Drainage Systems

Mitigate the adverse effects of urban stormwater runoff on the environment Reduce runoff rates Encourage groundwater recharge Reduce pollutant concentrations Buffer accidental spills from road drainage Reduce discharges to rivers or combined sewer systems Enhance amenity and provide wildlife habitats

SUDS components & key issues

Management train Sediment control System maintenance Open public space

SUDS ManualCIRIA C697

660 pages

Design criteria

Design criteria

Climate change allowances

Elvetham Heath

Scotland – mini swales

Drainage pipes underneath pick up runoff when it overflows down the grating for big events.

M40

Scotland - roundabout

Questions