Sustainable Drainage Systems (SuDS) are an
approach to drainage which seek to decrease the amount of surface
runoff, decrease the velocity of surface runoff, or divert it for
other useful purposes, thereby reducing the contribution it makes
to sewer discharge and flooding.
As well as controlling the quantity of runoff, SuDS can also
improve the quality of runoff, preventing pollutants from entering
the drainage system. SUDS will also 'green' the urban environment
and should provide landscape, amenity and biodiversity benefits
Techniques that come under the SUDS umbrella vary enormously but
usually involve some of the following components:
- Permeable and porous surfaces to reduce surface runoff
- Ponds/basins for temporary storage during high magnitude
rainfall events (detention basins) or longer term storage
- Pipework and channeling to divert water from undesirable
- Structures that increase the lag between a rainfall event and
discharge of water to the drainage system by increasing
SuDS are particularly
valuable in urban areas where high density development and
impermeable surfaces mean surface runoff can easily cause flooding,
either directly or indirectly through sewer flooding.
Work by Scotland and Northern Ireland Forum for Environmental
Research has shown that of the 767 SuDS sites in Scotland recorded
in late 2001, most were part of residential and commercial/retail
developments (48.6% and 22.4% respectively) as well as industrial
and roadside developments.
Case Studies (Construction Industry Research and Information
Urban Drainage Systems Network)
For further information read the CIWEM briefing report on
Multifunctional Urban Green Infrastructure
downloadable from the page resources sidetab.