Page 129 - Bexley SuDS DESIGN & EVALUATION

Source Controls providing collection &
conveyance

Water must either be kept at or near the

surface to allow runoff to flow into SuDS
structures, or it must be collected through Detailed Design
permeable surfaces.

The simplest method of collection of runoff
from an impermeable surface is to intercept it
as sheet flow from a hard surface. Where
runoff flows directly from hard surfaces to
filter strips or swales then runoff must leave
the hard surface effectively without the risk
of ponding.
Pershore High School, Worcestershire.
■ swales Low risk access road with 1.2m wide filter strip
source control and conveyance swale.
■ filter drains

Site Controls

Where runoff is collected at the surface, a

depression in the ground, mimicing hollows in 124
the natural landscape, is the easiest and most
cost effective way to manage large volumes Pershore High School, Worcestershire.
of water in the landscape. Swale conveyance into pond site control for
final treatment and storage.
Where landscape is limited, storage
opportunities within pavements and on roofs
should be explored.

Careful design can maximize opportunities
with different design volumes in different
places providing maximum opportunities for
multi-functional use and biodiversity.

■ basins

■ wetlands

■ ponds

■ storage structures

London Borough of Bexley SuDS D & E Guide © 2018 McCloy Consulting & Robert Bray Associates