SuDS in London - a guide

Prevention
Site design and management to stop or
reduce the occurrence of pollution of
impermeable surfaces; to also lower
the volume of runoff, by reducing
impermeable areas.
Public sewer
A sewer that is vested and maintained by
the sewerage undertaker (see s 219(1) of the
Water industry Act 1991).
Quietways
Proposed network of radial and orbital
cycle routes through London, linking key
destinations via direct back-street routes,
through parks, along waterways or treelined
streets.
Rain garden
A planted basin designed to collect and
treat surface water runoff.
Rain meadow
A field or drainage reserve that is capable
of flooding to absorb excess rainfall.
Rainwater butt
Small scale garden water storage device
that collects rainwater from the roof via
the drainpipe.
Rainwater harvesting or rainwater
use system
A system that collects rainwater from where
it falls, rather than allowing it to drain away.
It includes water that is collected within
the boundaries of a property, from roofs
and surrounding surfaces.
Receptor
A location that is subject to an impact,
either through flooding or pollution.
Certain types of measures can be
retrofitted at such locations.
Recharge
The addition of water to the groundwater
system by natural or artificial processes.
Retention pond
A pond where runoff is detained long
enough to allow settlement and biological
treatment of some pollutants.
Rill
A shallow channel or watercourse.
Risk
The chance of an adverse event. The
effects of a risk is the combination of the
probability of that potential hazard being
realised, the severity of the outcome if it
is, and the numbers of people exposed to
the hazard.
Risk assessment
A carefully considered judgment requiring
an evaluation of the consequences that
may arise from the hazards identified,
combining the various factors contributing
to the risk and then evaluating their
significance.
Runnel
A small river channel or course.
Runoff
Water flow over the ground surface to the
drainage system. This occurs if the ground
is impermeable, saturated or if rainfall is
particularly intense.
Soakaway
A subsurface structure that surface water
is conveyed into, designed to promote
infiltration.
Source control
The control of runoff at or near
its source.
Stockholm soil
Soil made from angular rock, specified soil
mix and water.
145 Appendices